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									                    Research: Current Projects
                          2000 Projects
Cotton Production

     Bioremediation Efforts for Sticky Cotton
      Vern J. Elliott

     31 Biological Control of the Cotton Aphid
      Kris Godfrey and Michael McGuire

     34A Remote Sensing in Cotton at Shafter, 2000
      Glenn J. Fitzgerald and William R. DeTar

     37B Approved Pima Variety Trials
      Robert Hutmacher

     39 Establishing Updated Guidelines for Nitrogen Fertility in Upland (Acala) Cotton
      Robert Hutmacher

     40 SJV Acala and Pima Testing Program
      Dick Bassett & Shane Ball

     43 Management of Key Cotton Arthropod Pests with Insecticides and Acaricides
      Larry Godfrey & Kevin Keillor

     44 Interaction of Cotton Nitrogen Fertility Practices and Cotton Aphid Population
      Dynamics in California Cotton
      Larry Godfrey, Jorge Cisneros, Kevin Keillor, & Bob Hutmacher

     45 California Upland Cotton Advanced Strains Variety Trials
      Robert Hutmacher

     46 Upland Cotton Varietal Response to Short-Season Versus Long-Season Management
      Robert Hutmacher, Steve Wright and Brian Marsh

     52 Narrow-Row (Double-Row 30 Inch and Double-Row 40 Inch) by Variety Trial
      Robert Hutmacher, Bill Weir and Brian Marsh

     53 Evaluation of Bollgard II Cotton for Lepidopteran Control & Performance under
      Commercial Productions
    Brian Marsh

   54 Agronomic Test of Improved Fiber Quality Pima Germplasm
    Richard Percy

   55 Root-Knot Nematode Management in Cotton
    Pete Goodell, Phillip A. Roberts and Chuck Haas

   56 Cotton Weed Control
    Brian Marsh

   83 Development of High Yielding, Pest Resistant Blackeye Bean Varieties for California
    Jeff Ehlers, Tony Hall and Blake Sanden

   84 Potato Late Blight Screening Nursery
    Ron Voss and Joe Nunez

   86 Importation of Peristenus spp. for the Biological Control of Lygus Hesperus
    C. Pickett

   87 Root-Knot Nematodes (Meloidogyne javanica) in Field & Vegetable Crops
    Phil Roberts

   88 Nightshade Control in Blackeyed Beans and Annual Morningglory Control in Blackeye
    David Bayer and Ernie Roncoroni
        Project: Bioremediation Efforts for Sticky Cotton
Project Leader: Vern J. Elliott
                 (661) 746-8003 (661) 746-1619 FAX
                 USDA ARS Shafter Research and Extension Center
     Objective: The Problem. Sap feeding cotton pests like aphids or whiteflies can excrete
                 a sticky, sugar rich liquid onto open cotton bolls. This sticky cotton as it is
                 called, poses serious difficulties at the textile mill. Machinery can be fouled to
                 the point that the cotton cannot be used. Consequently, sticky cotton is
                 difficult to sell and a production area can get a bad reputation that will hurt
                 sales for years to come. Although insect management can reduce the
                 chances of sticky cotton, no effective treatment currently exist to remove the
                 sugar contamination once it occurs. Our work is focused on applying special
                 strains of yeast to consume the sugar on the cotton fiber and reduce the
                 stickiness. If successful, this research would allow sticky cotton to be
                 cleaned up in the module and permit trouble free processing at the gin or
                 mill. This would give California cotton growers an important tool to protect the
                 well deserved reputation for quality cotton.

                  The Plan
                  Bioremediation offers a possibility of eliminating stickiness by using
                  microorganisms to consume the sugars. Yeasts have several characteristics
                  that would be useful in a bioremediation agent for sticky cotton. Yeasts
                  readily consume sugars, grow over a range of temperature and moisture
                  levels, and withstand drying. Honeydew is a sugar rich mixture that is
                  somewhat variable in composition depending on which insect is present. The
                  predominant sugars found on sticky cotton are melezitose, trehalulose,
                  sucrose, fructose, glucose, and trehalose . Other unique sugars such as
                  bemisiose can also occur. Consequently, it is important to identify strains of
                  yeast with the enzymes needed to break down these different sugars. The
                  present research was initiated to survey the ability of various plant
                  associated yeasts to utilize the sugars found in honeydew.

                  Methods Used
                  Naturally occurring yeasts were collected from cotton leaves, lint, and from
                  other plants growing in the San Joaquin Valley of California. A sub-sample of
                  250 strains was selected to evaluate the ability of these yeast to metabolize
                  some of the sugars found in insect honeydew. The yeast were grown on
                  Bacto YM agar for 48 hr to condition them physiologically, then suspended in
                  sterile water. Solutions of sugars (either sucrose, glucose, fructose,
                  melezitose, or trehalose) were prepared in a solution of Bacto yeast nitrogen
                  base, filter sterilized, then dispensed into 96 well microplates. Two controls
                  of either water or the nutrient base without added sugar were also tested to
                  check for growth on stored nutrients. Trehalulose was not available at this
                  time and therefore will be evaluated in later tests. Each strain by sugar
                  combination was tested in two replicates. Plates were incubated at 28° C and
                  growth was determined by periodically measuring turbidity over a 48 hour
                  period. Growth rate was measured by calculating the change in turbidity over

                  Results of the Study
                  All the sugars evaluated could be degraded to some degree by many of the
                  strains tested (Fig 1). When assessed across all 250 strains, sucrose
                  supported the highest average rate of growth followed closely by glucose
                  and fructose, then melezitose and trehalose. Essentially no growth occurred
                  in water or the nutrient base controls. The distribution of growth rates on any
                  given sugar was positively skewed with some strains showing much higher
                  rates than the average. When ranked by the maximum rate, fructose and
                  glucose supported the highest rate followed closely by melezitose and
                  sucrose. The maximum rate on trehalose was considerably lower. Many
                  strains could utilize more than one sugar and within the same strain, growth
                  rates on the different sugars tended to be correlated (Fig 2). These results
                  indicate that the naturally occurring yeast population in the San Joaquin
                  Valley will be a suitable source for selecting bioremediation agents for
                  whitefly and aphid honeydew. The positively skewed distribution indicates
                  that selecting strains for rapid rates of utilization will be successful.
                  Trehalulose has yet to be tested but given its prevalence in honeydew, it is
                  likely that strains will be found that can degrade this sugar. Ultimately,
                  selected strains will have to be tested for the ability to reduce or eliminate
                  stickiness as measured by the thermal detector test and lint processing trials.

                  These studies show that the yeasts living on cotton and other plants can
                  breakdown the sugars tested. More importantly, some strains with greater
                  rates of utilization have been identified. It was also encouraging that we
                  found yeasts strains capable of breaking down several different sugars.
                  These will be valuable as biocontrol agents.

         Project: 31 Biological Control of the Cotton Aphid
Project Leaders: Kris Godfrey, Environmental Research Scientist, CDFA Biological Control
                  Program, 916-262-1185 Michael McGuire, Research Leader USDA, ARS
                  Shafter Research and Extension Center, 661-746-8001
      Objective: The cotton aphid, Aphis gossypii Glover (Homoptera: Aphididae), is a
                  persistent concern in cotton production in the San Joaquin Valley. Over the
                  last 4 years, researchers at the California Department of Food and
                  Agriculture - Biological Control Program and the USDA - Agricultural
                  Research Service at Shafter have been conducting studies in an attempt to
                  construct a natural enemy complex that would complement the existing
                  natural enemy complex, thereby reducing cotton aphid densities. From these
                  studies, 2 introduced parasites, Aphelinus near paramali and Aphel. gossypii
                  Timberlake (Hymenoptera: Aphelinidae), have been identified as the initial
                  components for the new natural enemy complex. In addition, studies are
                  continuing on a fungus, Neozygites fresenii (Nowakowski) Batko
                  (Zygomycetes: Neozygitaceae), to determine what role, if any, it will play in
                  the new natural enemy complex. The research conducted this year has 2
                  aspects: establishment of the 2 introduced parasites across the San Joaquin
                  Valley, and efficacy testing of the fungus.

                  To establish Aphel. near paramali (ANP) and Aphel. gossypii (AG), a system
                  of parasite nurseries was established in Kern, Merced, and Madera
                  Counties. In Kern County, 6 parasite nurseries were established, and in
                  Merced and Madera Counties, 2 nurseries were established in each county.
                  Beginning in June in Kern County and July in Merced and Madera Counties,
                  the nursery sites were visited once per week to assess aphid densities. Once
                  aphids were found, releases of ANP and AG mummies began. From July 17
                  through August 24, 3,000 ANP and 7,200 AG mummies were released in
                  Kern County. From July 19 through August 30, 2,500 ANP and 5,300 AG
                  mummies were released in Merced and Madera Counties. Sampling of the
                  aphid populations began 2 weeks after the initial release of parasites. To
                  date, black mummies characteristic of aphelinid parasites have been
                  recovered in all counties. In Kern County, both ANP and AG adults have
                  been recovered, and in Merced and Madera Counties, only ANP adults have
                  been recovered. The parasite releases and sampling will continue until
                  cotton harvest. After harvest, habitats near the cotton field will be examined
                  for aphids and parasites.

                  Another biological control we are currently examining, in cooperation with
                  scientists at the University of Arkansas is a fungus called Neozygites fresenii
                  that attacks cotton aphids. In Arkansas, this fungus occurs naturally and
                  causes widespread crashes of aphid populations and removes the need for
                  insecticide applications. In September of this year, we have released the
                  fungus in plots infested with aphids. Since most insect pathogenic fungi are
                  dependent on moisture to spread, our experiment involved three irrigation
                  treatments; in furrow, overhead sprinkler and no irrigation. Measurements of
                  fungus establishment and spread will be made until defoliation.

                  In related research, efforts are currently being made to obtain at least 2 new
                  species of aphid parasites, Aphidius colemani Viereck (a strain from Chile)
                  and Lipolexis oregmae (Gahan) (Hymenoptera: Aphidiidae), for testing in
                  cotton in the San Joaquin Valley. It is anticipated that these parasites may be
                  available late in the year.

         Project: 34A Remote Sensing in Cotton at Shafter, 2000
Project Leaders: Glenn J. Fitzgerald, Physical Scientist, (661) 746-8009
                  William R. DeTar, Agricultural Engineer, (661) 746-8011
                  USDA-ARS, Shafter, CA
      Objective: Remote sensing can be an important tool for detecting within-field variability
                  in the crop and soil. When flown regularly during the cropping season, this
                  information can show temporal changes in crop and pest development. The
                  Shafter Airborne Multispectral Remote Sensing System (SAMRSS) is the
                  principal tool used to acquire remote sensing data for cotton research at
                  Shafter. This is the third year SAMRSS has been flown in a light aircraft.
                  Over 20 flights will be made in 2000 to characterize cotton dynamics in
                  research plots and cooperating growers fields. Funding for flights was
                  provided for a second year by a NASA EOCAP grant.

                  SAMRSS consists of four digital cameras, three of which have special filters
                  that allow only green, red, or near infrared light into each of the cameras.
                  The particular wavelengths were chosen because they contain important
                  information about plants, soils, and water. The fourth camera is a thermal
                  camera that measures heat from the earth's surface. This camera can
                  measure canopy temperature which is important in water stress studies.
                  When water evaporates from a surface is takes heat with it causing the
                  surface to cool. Thus, a healthy, transpiring plant has cooler leaves than the
                  surrounding air. Conversely, as a plant undergoes water stress, the
                  temperature of its leaves increases. Thus, if canopy temperature can be
                  measured with remote sensing, it could become an input to an irrigation
scheduling model for an entire field.

During 2000 the remote sensing project at Shafter continued investigations
on early detection of spider mites and water stress in cotton. Once images
are acquired and stored on computer they are processed and analyzed. An
image processing procedure was developed and tested on data collected in
1998 and 1999 and was found to consistently show mite damaged areas
within the Shafter research plots. This will be implemented on 2000 data to
test the ability of the procedure to detect mites for a third season.
Additionally, in 2000 there was a heavy aphid infestation in the research
plots. A procedure will be tested to detect these pests as well.

Other work being performed at Shafter includes a cooperative effort with
Opto-Knowledge Systems, Inc. (OKSI) for development of hyperspectral
imaging technology in cotton. Hyperspectral remote sensing involves special
instruments capable of acquiring images of cotton in dozens or hundreds of
wavelengths. Thus it might be possible to develop, a spectral "signature" for
mite damage that could be detected even before the human eye can see
damage. This same technology could be used for water stress and other
stresses in cotton. The figure at the end of this article shows an example of
this technology. Spectra of mite damaged and healthy leaves are compared
showing that there are distinct differences. These differences could lead to
the ability to identify mite damage through hyperspectral imagery. This
project was funded by a grant from Cotton Incorporated.

A new project was begun, called Ag20/20 that will showcase the application
of remote sensing technology to the management of a cotton farm. A 3800
acre farm near Lemoore was flown on over 20 dates in 2000 using the
SAMRSS package and some flights had the OKSI hyperspectral imager on
board. Although the images have not yet been analyzed, it may be possible
to provide the grower with variable rate gypsum recommendations when
combined with ground data collected from one of the fields on the farm.
Other possible uses of this technology include, irrigation scheduling, pest
detection, measurement of soil variability, and mid-season yield estimation.
Additionally, geographic information can be added to the imagery from data
acquired with global positioning systems (GPS) from locations identifiable in
the images. Thus, anomalies seen in the images can be located on the
ground. This could improve scouting and sampling efforts since maps and
GPS receivers could be provided to field scouts to locate areas of interest
located in the imagery. They could then pinpoint problems on the ground.

Plans for the future include:
1) Continued development of a mite spectral "signature" that will allow
detection of mites in any field from remotely sensed imagery and associated
image processing techniques,
2) Continued development of a water stress model allowing estimation of
water stress and canopy temperature from remotely sensed images,
3) Comparison of SAMRSS imagery with satellite, film-based infrared, and
an inexpensive digital camera to determine the advantages and
disadvantages of these technologies for the agricultural community.

Click here to view spectrum of a mite damaged portion of a leaf compared to
a healthy leaf.
        Project: 37A Approved Acala Varieties Evaluations: Multi-County Evaluations in
                 the San Joaquin Valley
Project Leader: Bob Hutmacher, UCCE Extension Agronomist, UC Shafter REC & Agronomy
                 & Range Science, UC Davis

                B.L. Weir, Farm Advisor, UCCE-Merced County
                R.N. Vargas, Farm Advisor, UCCE-Madera County
                Dan Munk, Farm Advisor, UCCE-Fresno County
                B.A. Roberts, Farm Advisor, UCCE - Kings County
                S.D. Wright, Farm Advisor, UCCE-Tulare County
                B.H. Marsh, Farm Advisor, UCCE-Kern County
                M. Keeley, R. Delgado, S. Perkins, L. Banuelos, J. Wroble, T. Martin-Duvall
     Objective: Eight county test sites were selected for the 2000 Approved Acala trials.
                Weather during the March 10 through March 23 period was unsuitable for
                planting, with inadequate heat units for good probability of germination/
                emergence. Soil temperatures and heat units improved after that period, and
                all plantings in these trials occurred between March 30 and April 26.

                Six of the tests are large-scale evaluations at grower sites in Kern, Tulare,
                Kings, Fresno, Madera and Merced counties. At these locations, most trials
                are 1300 foot run lengths, although some are as short as 800 feet and others
                as long as 2600 feet. Four replications were used at all locations. In addition,
                there are two smaller tests at both the University of CA Shafter Research
                and Extension Center and the West Side Research and Extension Center.
                Even in these smaller tests, plot sizes remain 300 feet in length by four rows
                in width. At the six large-scale county grower locations, a total of thirteen
                Approved Acala varieties were planted at each of the test sites. The Acala
                varieties included in the test include Maxxa, GTO Maxxa, DP-6211,
                Phytogen-33, DP-6207, SJ-2, GC-500, BR-9605, C-166, C-144 (Ultima), and
                three new releases for this year (GC-505, GC-507, and C-176 (Riatta RR). At
                the West Side REC and Shafter REC locations, two non-Acala CA Upland
                varieties (DPL Nucotton-33B, Stoneville BXN-47) will also be grown in this
                test (in addition to the thirteen Approved Acalas) for comparison purposes.

                Data collection includes the following: plant population evaluations and
                varietal comparisons in incidence of foliar symptoms of Verticillium. In
                addition, during the past few weeks, field evaluations have been done to
                compare crop progress in nodes above white bloom (NAWF). This data has
                been collected across all field replications, but has not been analyzed.
                Evaluations for incidence of Verticillium wilt symptoms was done on two
                additional dates during August and early September, and earliness will again
                be measured on as many varieties as possible (all if personnel and
                resources allow, fewer if necessary) as nodes above white flower, nodes
                above cracked boll, efficacy of defoliation following harvest aid applications,
                and timing of 30 to 50 % open boll.

                Plots in these large-scale trials will be harvested by commercial pickers, and
                weights determined using in-field weighing boll buggies. In the smaller trials
                at the Research and Extension Center locations, modified commercial
                pickers able to pick into sacks will be used, and individual plot weights will be
               determined on full row lengths. In both types of trials, six pound samples will
               be collected in all field replications at harvest, and samples analyzed for
               seed weight, gin turnout, with subsamples of lint sent to the USDA Classing
               Office for HVI analysis. Results will be reported at county meetings, annual
               meetings of the UC cotton group, at the annual Workgroup and Cotton
               Incorporated meetings. In addition, the information will be presented in the
               annual variety trial issues (yield and quality) of the CA Cotton Review
               Newsletter, and on the web site for cotton maintained by the University of CA
               ( Basic yield results from the multiple locations in the
               1999 Approved Acala Variety trials are as follows in Table 1. More
               complete results, including fiber quality data are available in the Variety trial
               information contained at the above-mentioned web site or in January and
               February issues of the "California Cotton Review".

        Project: 37B UCCE Approved Pima Variety Trials
Project Leader: Bob Hutmacher, UCCE Extension Agronomist, UC Shafter REC & Agronomy
                 & Range Science, UC Davis

               Ron Vargas, Bill Weir, Steve Wright, Bruce Roberts, Dan Munk, Brian Marsh,
               Mark Keeley, and Raul Delgado
    Objective: 1999 Studies
               The objectives of these studies with Pima are to evaluate approved varieties
               under different environmental conditions and management. The studies are
               part of a regional Beltwide Pima variety evaluation that includes Texas, New
               Mexico, Arizona and California, and are supported in part through the
               California Crop Improvement Association. Two UCCE Research Center test
               locations were used in the 1999 trials, the West Side and Shafter Research
               and Extension Centers of the University of California. The West Side location
               is in a clay loam soil with an soil profile largely unrestricted to rooting to a
               depth of 6 feet or more, while the Shafter location is a sandy loam soil with
               surface infiltration problems which limit mid- and late-season irrigation water
               penetration and effective rooting depth to 2 to 3 feet in the mid- to late-

               In order to provide a reasonable limit on the number of varieties in the tests,
               the entries include newly-approved varieties for the current year, varieties
               released last year that are in their second year of testing, plus the top 4 or 5
               previously-approved varieties (in terms of planted acreage). The new
               varieties are the focus of the tests, but they only remain in the tests for the
               first two years following release unless that variety moves into the top 4 or 5
               varieties in planted acreage. Released varieties also may not show up in the
               tests if the seed companies request that the variety is for a special market
               and don't want it in multiple location testing, or when inadequate seed
               supplies exist for large-scale testing.

               Objectives were also to evaluate varieties under different environmental
               conditions and management. The number of test locations was expanded
               considerably in 1998 and 1999 in response to increasing Pima plantings and
               the need for a broader base of information on varietal performance. Pima
               variety trials had limited financial support in 1999, supported largely from
               general research funds of UCCE Specialists and Farm Advisors, and in part
               through grants from the California Crop Improvement Association. In 2000
               the Supima Association provided some supplemental funding to assist in
               running these trials. Two test locations (UCCE Shafter and West Side
               Research and Extension Ctrs.) were used with 8 varieties in the 1999 trials,
               plus four additional locations where growers agreed to include 6 varieties.
               The four large-scale test sites were on grower-cooperator locations in Kern,
               Kings, Fresno and Merced counties. Approved Pima varieties included in the
               tests are shown in Table 1. Results for the six varieties grown at five
               locations are shown in Table 1, data for the eight varieties at two locations
               (West Side and Shafter REC) in Table 3, and yields at the Fresno County
               saline site are in Table 3. Fiber quality information from the trials is shown in
               Table 2.

               This project gives growers a continuously-updated comparison of newly-
               available varieties versus those varieties which have been available for one
               or more years. This data base has been significantly improved by increasing
               the number of test locations to include 6 sites, instead of the 3 locations used
               in 1996 or 2 locations used in 1997. Grower confidence in the utility of these
               tests has been improved with this marked increase in number of locations,
               and we hope to continue this expanded testing in the future.

               Across all locations and varieties, 1195 lbs of lint per acre were produced in
               the Pima Approved Variety Trials this year, compared with 791 lbs/acre
               (1998), 1703 lbs/acre (1997) and 1256 lbs/acre in 1996 trials. Planting dates
               in 1999 trials ranged from April 12 to April 27, and plants in most locations
               suffered from delayed development and flowering due to cool conditions that
               prevailed into mid-June. Pest problems (lygus in some locations, spider
               mites in three sites) were causes of moderate early and mid-season losses
               in at least three locations. Data from multiple years should be considered in
               making variety choices, as one year's data may not represent long-term
               performance. For instance, CH-252 performance in yield tests has been
               similar to S-7 in many locations and numerous years prior to 1999, but 1999
               yields were significantly lower.

               2000 Studies
               Four county test sites were selected for the 2000 County Approved Pima
               Variety trials in addition to the two UCCE Research Center sites. Test plots
               were planted between March 28 and April 16. Four of the tests are large-
               scale evaluations at grower sites in Kern, Kings, Fresno, and Merced
               counties. At these locations, trials range from 800 foot runs to 2600 foot run
               lengths. Four replications were used at all locations. In addition, there are
               two smaller tests at both the University of CA Shafter Research and
               Extension Center and the West Side Research and Extension Center. Even
               in these smaller tests, plot sizes remain 300 feet in length by four rows in

        Project: 39 Updated Guidelines for Nitrogen Management in Acala Cotton
Project Leader: Bob Hutmacher, UCCE Extension Agronomist, UC Shafter REC & Agronomy
                 & Range Science, UC Davis
                 Robert L. Travis and Bill Rains, Agronomy and Range Science, UC Davis

           B.A. Roberts, B.H. Marsh, Bill Weir, R. Vargas, S. Wright, D. Munk, M.
           Keeley, R. Delgado, S. Perkins, L. Banuelos, J. Wroble, T. Martin-Duvall
Objective: The response of Acala cotton in California to a range of applied N treatments
           are under investigation in a multi-year, multi-site experiment. Goals are to
           identify crop growth and yield responses to applied nitrogen and to provide
           information to better assess the utility of soil residual N estimates in
           improving fertilizer management. Results obtained during the first four years
           of this project have shown positive responses to increases in applied N
           across the 50 to 200 lbs N/acre range in only 10 out of 31 test sites (8
           locations by 3 years, 7 locations in fourth year). These findings indicate that
           while it is still true that 50 to 60 lbs N are needed per bale of cotton produced
           under CA conditions, more efforts should be put into identifying plant N
           requirements that can be met from residual soil N, rather than solely from
           fertilizer N applications.

            Incentives to consider adjusting nitrogen management practices for cotton
            and other CA crops come from several areas of concern. It has been
            recognized for many years that mid and late-season nitrogen management
            has an impact on progress toward defoliation and harvest. High nitrogen
            levels can increase problems with some late-season pests (silverleaf
            whitefly, aphids) that can influence lint quality. Higher than desired nitrogen
            levels during bloom and early boll filling can also promote vegetative
            development at the expense of fruit retention under some conditions. An
            additional area of concern in recent years has been the fate of nitrogen
            applied in excess of plant requirements. If plants grown in the rotation
            sequence do not have deep enough roots to intercept applied and residual
            nitrogen, its eventual movement through the soil profile has been shown to
            cause nitrate contamination of shallow groundwater in a wide range of

            Materials and Methods.
            In the first full year of the multi-site studies (1996), the fertilizer treatments
            ranged from a low of 50 lbs total N/acre to 200 lbs N/acre. Four treatments of
            50, 100, 150 and 200 lbs N/acre were applied in late May (prior to the first
            within-growing season irrigation), and in three supplemental treatments (50,
            100 or 150 lbs N/acre initially applied), a second N application of 50 lbs
            N/acre was applied in June just prior to the second (pre-flower) within-
            season irrigation. In 1997 to 2000, the experiments were simplified down to
            four basic treatments (50, 100, 150 and 200 lbs N/acre) due to the lack of
            crop growth and yield responses to split-application treatments as well as
            grower concerns over the practicality and expenses involved in split
            applications and potential for damage to plants associated with getting
            application equipment in prior to the second irrigation. Soils were sampled at
            five locations per replication to a depth of 8 feet at all sites for analysis of soil
            NO3-N, NH4-N, PO4-P and K.

            Samples were collected in 1 foot increments to a depth of 4 feet, and then in
            twofoot increments to 8 feet depth. While there were four field replications
            used in determining yield, growth and petiole nutrient responses to
            treatments, only the first three field replications were used in soil tests.
            Elemental analyses were conducted on both KCl extracts (which were frozen
            after collection until analyzed) as well as on composite, air-dry samples run
            to complement data from soil extracts. Petioles were collected at intervals
            representing a range of growth stages at all sites.
Results and Summary of Data

Soil Nitrate-N Levels - Treatment Effects. Soil samples were collected to a
depth of 8 feet in May (or in several cases, April) (post-planting) in all years
of the trials. This data is far too extensive to go over here. In addition, there
are recognized limits in interpreting this type of data, since values change
over time with processes such as mineralization and denitrification. However,
these changes in soil NO3-N over time still represent a general index of soil
changes in N status resulting from crop uptake and other processes / losses
during the growing season.

Soil data varies quite widely across years and site, but some generalizations
can be discussed. Soil NO3-N levels in the upper 2 feet of the profile at the
Spring 1998 sampling ranged from a low of 37 lbs N as NO3-N per acre at
the Shafter REC site to 103 lbs N as NO3-N per acre at the Madera County
site in spring of 1998, with an 8-location average of about 65 lbs N as NO3-
N/acre. The range in soil sample spring nitrate levels was even greater in
1999 and again in 2000, with the highest N site having over 200 lbs N as
NO3-N available in the upper two feet of the profile ( in a field where cotton
planting followed corn). Soil NO3-N levels in the upper 2 feet of the profile at
the Spring 1999 sampling ranged from a low of 36 lbs NO3-N per acre in the
low N treatment at the West Side REC to a high of 241 lbs NO3-N per acre
at the Madera County site. Most other sites in the spring upper 2-foot
sampling in 1999 ranged from about 45 to 110 lbs NO3-N per acre in the
upper 2 feet of soil (data not shown).

Data in general has indicated that most net depletion of soil NO3-N was seen
in the upper four feet of the soil profile. It could be argued that this depletion
could result from leaching losses as well as denitrification, but the measured
presence of significant root mass at depths down to 6 to 7 feet indicates that
plant uptake is another reason for net depletion even at the 4 to 8 foot zone.
Most other sites had root activity primarily in the upper 3 to 4 feet of the soil
profile. As levels of applied N increased at most sites, soil NO3-N levels in
the 4 to 8 foot zone of the soil profile generally increased. If the cotton or
subsequent crops cannot access this N source, it would be subject to
leaching losses if moved further by water moving through the soil profile.

Lint Yields. It is important to get a multi-year, multi-location perspective in
analyzing lint yields across these nitrogen treatments (yield tables on
following page). Some generalizations are possible for each year.

1996 Moderate yields across all sites. In all but one of the eight field sites
used in 1996, there were no significant effects of nitrogen treatments on lint
1997 more locations showing significant yield reductions with N applications
of 50 to 100 lbs N/acre Yield responses to applied N were not observed in
locations with low initial soil NO3-N levels
1998 a very difficult production year, with cool and wet spring conditions,
delayed growth, and abnormal progression of crop development associated
with early cool conditions, hot late summer conditions which influenced
flower and boll retention, and a cool fall which delayed progress toward
defoliation and harvest. Yields were extremely low in fields across most of
the San Joaquin Valley. Under these low yield potential conditions, less N is
1999 Much higher yields at most study sites in 1999 put a higher N "load" on
the plants (higher need for N to meet fruit development requirements)
                 Future Plans - Related Studies.
                 This field project was again conducted in 2000 in order to strengthen the
                 data set and complete the field portion of this project.

        Project: 40 SJV Acala and Pima Testing Program
Project Leader: Dick Bassett & Shane Ball, Cotton Specialists Jim Bergman & J. Scott
                 Perkins, Ag. Techs. (661) 746-8028
     Objective: Acala
                 Six of the entries in the regular large-scale tests completed the third year of
                 testing and thus were eligible to be considered for approval as SJV Acalas
                 (Table 1). Five of them were ultimately approved by the SJV Cotton Board in
                 March. Three are transgenics, the first such cottons to enter the testing
                 program. Two of these contain the gene for resistance to Roundup herbicide.
                 These are CPCSD's C-176, which has a Maxxa background, and Germains
                 GC-9646. These have been renamed and will be marketed as Riata and GC-
                 546RR respectively. The third transgenic is GC-9645, renamed GC-545BG.
                 It contains the BT gene for worm resistance. The two non-transgenics that
                 were approved are GC-9642 (renamed GC-507) and GC-9643 (renamed

                 The C-176 (Riata) significantly out yielded the standard in 1999, but not in
                 1998. Very few measurable differences were found in growth and fruiting
                 characteristics, fiber quality or spinning performance when compared to the
                 standard. The two Germain transgenics were below the Maxxa yield at most
                 locations, but both possessed excellent quality traits, especially the GC-9646
                 (GC-546RR). The latter variety is characterized by a shorter, more
                 determinate growth and fruiting pattern. The two conventional cottons, GC-
                 9642 and GC-9643, lint yields were the same as Maxxa, although there were
                 response differences in 1998 and 1999. The fiber and yarn quality
                 characteristics were equal to or slightly better than Maxxa. The DP6100RR
                 was inconsistent in yield performance and was not approved by the SJV
                 Board, primarily over concerns about substantial reductions in yarn strength,
                 especially when spun into the fiber count yarns.

                 The UA-5 fell below the S-7 yield when averaged over all test sites, but the
                 difference did not reach statistical significance (Table 2). Any yield deficits
                 are primarily a result of a lower lint percent and gin turnout. It grows taller, is
                 more indeterminate and somewhat later maturing than the S-7. This may
                 account for its relatively poorer showing in the 1998 shortened season than
                 in the other two years. The more vigorous, indeterminate growth
                 characteristics make it less susceptible to the premature bronzing and leaf
                 senescence that often occurs with the S-7 and similar types. Overall fiber
                 and yarn qualities are improved. The slightly lower micronaire is a result of
                 improved fineness, rather than immaturity. These fiber characteristics
                 translate into a stronger and more even yarn.
        Project: 43 Management of Key Cotton Arthropod Pests with Insecticides and
Project Leader: Larry D. Godfrey, Entomology, UC Davis (530) 752-0473
                 Kevin Keillor, Shafter REC & Entomology, UC Davis (661) 746-8032
     Objective: INTRODUCTION:
                 Insecticides and miticides represent a large portion of the budget required to
                 grow cotton in the San Joaquin Valley. Lygus bugs, cotton aphids, spider
                 mites, and silverleaf whiteflies are key pests of SJV cotton. In addition,
                 Lepidopterous larvae, particularly beet armyworm, appear to be an
                 increasing problem. Research-based, unbiased information needs to be
                 available to growers and PCAs so that they "get the most bang for the buck"
                 in pest control activities. These pests, depending on the year, reduce cotton
                 yields up to 15% with each individual pest inflicting as high as 4-6% loss.
                 Losses from arthropod pests and costs of control were on an increasing
                 spiral from 1994 to 1997; however, from 1998 through 2000 these values
                 were more moderate.

                 Insecticides are an important part of integrated pest management programs.
                 However, in order to refine and to advance IPM programs, research on the
                 role of insecticides needs to continue. Three primary areas are of importance
                 1.) incorporating new insecticides into IPM programs including the effects of
                 these materials on non-targets, efficacy on pests, yield impacts, etc., 2.)
                 efficacy of registered materials on pest populations as a means of
                 forewarning the development of resistance and determining the cost-
                 effectiveness of products, and 3.) the impacts of registered materials on
                 natural enemies in order to thoroughly evaluate product fit into effective IPM
                 programs. Changes in registration guidelines, such as the Food Quality
                 Protection Act, also alter the availability insecticides and this hastens the
                 need for additional research.

                 1.) Develop an expanded database on the current efficacy of
                 labeled/recommended insecticide and acaricide products on key insect and
                 mite pests of cotton in the San Joaquin Valley and record the impact of these
                 products on beneficial arthropods with the objective of providing better
                 guidelines on pesticide use.

                 2.) Evaluate the effectiveness of new candidate insecticide/acaricide
                 products on key San Joaquin Valley cotton pests, the impact of these new
                 compounds on populations of beneficial arthropods, and devise strategies for
                 utilization of these new products.

                 3.) Provide outreach to growers, PCAs, UCCE personnel, and others in the
                 cotton industry through appropriate field days, meetings, and publications.

                 Replicated field plots were established to evaluate the effect of registered
                 and experimental compounds on cotton aphids at the Shafter Research and
                 Extension Center. Similar studies on spider mites and lygus bugs were
                 conducted at the West Side Research and Extension Center. Aphid
                 treatments were applied on 3 August on plots measuring 6 rows by 70 feet (4
                 replications of each treatment). Pretreatment aphid populations averaged
                 76.6 per leaf. Efficacy was evaluated at 3, 7, 14 and 21 days after treatment.
                 Selected treatments were re-applied and further evaluations were conducted.
                 Treatments examined included registered materials (e.g., Provado, Lorsban,
                Furadan, Thiodan, Vydate), experimental materials (Actara, Fulfill, Calypso,
                Assail), and Bollwhip (a neem based product). Post-treatment populations
                were as high as 377 aphids per leaf. Data are being summarized and
                analyzed at this time.

        Project: 44 Interaction of Cotton Nitrogen Fertility Practices and Cotton Aphid
                 Population Dynamics
Project Leader: Larry D. Godfrey, Entomology, UC Davis (530) 752-0473
                 Jorge Cisneros, Entomology, UC Davis (530) 752-0473
                 Kevin Keillor, Entomology, UC Davis (661) 746-8032
                 Bob Hutmacher, Shafter REC & Agronomy & Range Science, UC Davis

                Cooperators for Complementary Studies Conducted in Grower Fields:
                Pete Goodell, UC IPM Project, Kearney Agricultural Center
                Brian Marsh, UCCE Kern County
                Bruce Roberts, UCCE Kings County
                Steve Wright, UCCE, Tulare County
                Dan Munk, UCCE, Fresno County
                Ron Vargas, UCCE, Madera County
                Bill Weir, UCCE, Merced County
     Objective: During the last 10 years, the cotton aphid (Aphis gossypii) has developed
                from a non-pest to one of the most significant insect pests of California
                cotton. This insect pest has joined lygus bugs, spider mites, silverleaf
                whitefly, and beet armyworms as a key arthropod pest of California cotton.
                The most significant cotton aphid outbreaks occurred in 1997; an estimated
                3.5% yield loss occurred which was estimated at $34 million in crop loss and
                an additional $38 million in control costs were incurred to "manage" this one
                insect pest. Cotton aphid infestations damage the cotton crop in several
                ways. On vegetative stage cotton, aphid feeding stunts the plant growth.
                However, only the highest, most prolonged early-season infestations result in
                a yield reduction or delay in crop maturity. During the mid-season (July to
                mid-August) cotton aphids reduce cotton lint yields since the aphids act as a
                significant sink, competing with the bolls, for carbohydrates. The late-season
                infestations (mid-Aug. to Sept.) are problematic because the aphids deposit
                honeydew on the exposed cotton lint, which reduces the lint value. Reasons
                for this change in pest status of cotton aphid are unclear; however, one of
                the most noticeable changes in cotton production over the last 10-15 years is
                the use of a plant growth regulator instead of irrigation and nitrogen deficits
                to limit early-season cotton vegetative growth. This has allowed cotton
                production practices in the SJV to evolve to higher nitrogen fertilization and
                irrigation inputs. Host plant conditions including high nitrogen and adequate
                moisture are generally optimal for aphid population growth and development.
                Insecticide use patterns (some of which directly or indirectly affect aphid
                populations), cotton varieties, the crop mosaic in the SJV, and other factors
                may also be acting upon aphid populations. Several species of insects have
                been shown to respond positively to higher levels of nitrogen, and similarly,
                small plot studies have shown more cotton aphids in highly nitrogen fertilized
                plots compared with low fertility areas. The idea of balancing the amount of
                nitrogen needed for optimal cotton yield with the level required to mitigate
cotton aphid population build-up is the goal of this project. Utilizing cultural
control measures such as nitrogen management could play an important role
in cotton aphid management. Biological control, predators and parasites, of
mid- and late-season aphid outbreaks is only moderately effective. Relying
on insecticides for aphid control adds undesirable production costs and also
promotes the development of insecticide resistance in this aphid pest.
Therefore, additional non-chemical control measures would fill an important

1) Study the influence of cotton nitrogen fertilization practices on cotton aphid
population dynamics and seasonal buildup in cotton.

2) Identify specific crop carbohydrate and N status associated with higher
aphid densities during specific crop growth stages.

Two specific studies were conducted at the Shafter REC in each of 1999 and
2000. In addition, the REC was included as a location in the "grower field"
strip tests evaluating the effects of nitrogen on cotton yield as well as on
cotton aphid populations.

Nitrogen Effects on Aphid Biology: Cotton aphid reproduction, survival,
and development were studied under treatments of 0 (=20 lbs. residual in
soil), 50, 100, 150, 200, and 250 lb./A nitrogen (ammonium sulfate fertilizer)
in 1999 and 2000. There were also treatments of 200 lb./A nitrogen split in 4
applications (applied every two weeks), an alternate source of nitrogen (200
lb./A of urea), and a "balanced" fertilization (200 lb./A nitrogen + 100 lb./A
K2O) in 1999. In 2000, the nitrogen rate treatments studied in 1999 were
used, as well as several combinations of nitrogen and potassium were
studied. Cotton aphids from a laboratory colony were placed on to five to
eight plants in each plot on July 16 and July 10 in 1999 and 2000,
respectively. These aphids were enclosed in single-leaf cages and were
monitored daily for their survival, fecundity, and generation time.

Results from detailed studies on the effects of nitrogen on cotton aphid levels
showed that, for the first generation of aphids exposed to the conditions, the
aphids from high nitrogen plots, especially the ones reared on plants
fertilized with ammonium sulfate only, produced significantly more offspring
and had shorter generation times, i.e., the time needed to go from a new-
borne aphid to an adult, than the aphids from low nitrogen plots. Generation
times ranged from 12.3 days (0 lbs./A nitrogen) to 9.3 days (250 lbs./A
nitrogen). Similarly, the number of offspring per adult averaged 1.7 and 5.3
with the low and high nitrogen regimes, respectively. Conversely, potassium
seemed to have a detrimental effect on the aphid processes. Thus, aphids
from the treatment that had the "balanced" fertilization (200 lb./A nitrogen +
100 lb./A K2O) had a lower fecundity and longer generation time than
individuals from the two highest nitrogen treatments (200 and 250 lb./A of
ammonium sulfate). No differences in aphid survival were found among
treatments; however, the overall survival was low (about 33%). Data from
2000 are still being summarized. However, the initial results suggest that the
aphids developed faster (~6 days from nymph to adult in the high nitrogen)
and produced more offspring (more than 20 per adult) in 2000 than in 1999.
This corresponds with the aphid outbreak observed in the natural field
population in 2000.
Nitrogen X Insecticide Aphid Study: In a second study at the REC,
nitrogen rates ranging from 0 to 200 lbs./A were set-up and at the onset of
aphid build-up, insecticide treatments of Capture and Provado (and an
untreated) were placed in each nitrogen treatment plot. In 2000, a 200 lb./A
nitrogen + 150 lbs./A K2O was added. After establishing the fertility by
insecticide combinations, aphid populations were monitored weekly via leaf

For the nitrogen by insecticide study, at 3 weeks following the insecticide
application, in the untreated plots, aphid numbers increased slightly across
the increasing nitrogen levels (10.9 to 24.8 aphids per leaf from 20 to 200
lbs./A N). Aphids populations in 1999 did not develop until late August/early
September. At this time, the applied nitrogen rates had undoubtedly been
greatly altered and/or depleted by the growing crop. This probably muted the
effect. Provado controlled the infestation which is in agreement with its
activity spectrum. At 0 to 100 lbs./A N, the aphid population was 50-75%
higher in the Capture-treated plots compared with untreated. However, at
150 and 200 lbs. N/A, there were 3 and 4 times, respectively, more aphids in
the Capture plots compared with the untreated. In 2000, the naturally-
occurring aphid population in the nitrogen by insecticide plots was much
higher than in 1999 and populations developed earlier (treatments were
applied on 26 July). Data are still being collected and results are being
summarized/analyzed but some treatments averaged as high as 350 aphids
per leaf.

Large Plot Strip Tests: Replicated field studies were set up and managed
by the Cotton Agronomist and Cotton Farm Advisors in grower fields and
contributed to the overall goals of the REC studies. The treatments were set
up in strips, generally 8 rows wide x the field length (up to 1/4 mile long) x 4
blocks. Target nitrogen rates in these studies were 50, 100, 150, and 200
lbs. N/A; the lowest rate utilized the residual soil nitrogen and therefore
varied across locations. The three highest rates were the residual plus the
appropriate amount of applied N generally in June. Field sites were located
in Tulare Co., Fresno Co./West Side Research and Extension Center, Kings
Co., Merced Co., Madera Co., and Kern Co. (Shafter Research and
Extension Center and in a grower field). Planting dates varied across
locations but were generally in mid-late April in 1999 and early April in 2000.
Cotton aphid populations were sampled at weekly intervals from each plot
from July to September. A ten-leaf sample, fifth main stem node leaf from the
top, was used. Aphids were counted with the aid of 50X magnification. Aphid
number, separated into color morphs and winged vs. unwinged aphids, was
recorded for each sample.

In the grower field strip studies, cotton aphid populations were generally low
in 1999 and moderate in 2000, but levels responded to nitrogen regime.
Populations generally built-up late in the season at a time when the nitrogen
levels had likely largely equilibrated or at least were greatly altered compared
with the treatment regimes. In 1999, aphid populations developed in six of
the eight sites. The highest aphid density was ~33 per leaf. However, at all
the six sites with aphids, there was a trend with more aphids at the higher
nitrogen levels; a 3-4X range was commonly seen from the 50 to 200 lbs./A
treatments. Similarly, the percentage of leaves with aphids also responded
positively to nitrogen level.
        Project: 45 California Upland Cotton Advanced Strains Variety Trials
Project Leader: Bob Hutmacher, UCCE Extension Agronomist, UC Shafter REC & Agronomy
                & Range Science, UC Davis
                Cooperators: Mark Keeley, Raul Delgado, Scott Perkins, Shafter & West
                Side REC staff, Brian Marsh, Dan Munk, Steve Wright, Bruce Roberts, Bill
                Weir, Ron Vargas
     Objective: Project Summary
                A series of variety trials (both large-scale grower fields, plus two or three
                screening trials in small plot studies) were done on CA Upland cotton
                varieties in the San Joaquin Valley. This report only covers the "Advanced
                Strains" variety trials on the CA Upland varieties, with these trials conducted
                only at the West Side and Shafter REC locations. Overall goals of the project
                are to identify field performance in yield and quality of varieties seed
                companies are bringing in to the SJV region. This information is designed to
                supplement that provided by the San Joaquin Valley Cotton Board (for Acala
                and Pima entries in the Approved variety trials) plus the UCCE Farm Advisor
                tests on Approved Pima and Approved Acala entries. The "Advanced
                Strains" trials supplement the "Large-Scale CA Uplands Variety Trials" ,
                providing an opportunity for field trials with varieties where there is little prior
                performance information in the San Joaquin Valley. Seed availability is often
                quite limited on some of these varieties, so the plot sizes and seed
                requirements are small enough to allow testing to begin prior to large-scale
                seed increases.

                  The tests do not overlap those underway in other SJVCB or UCCE trials.
                  Data collected includes the following: final mapping will be done on select
                  varieties at all locations, with all yields machine-harvested and weighed. In-
                  season and final mapping includes data on height, number of nodes,
                  vegetative nodes, percent bolls at positions 1, 2, 3 and greater, identification
                  of the 95% zone for yield production, percent retention of fruit in the first five
                  fruiting branches, and the number of bolls per plant.

                  Yield data and a six pound seedcotton sample will be collected in all plots in
                  2000 as in 1999. Seedcotton samples will be ginned at the UC Shafter
                  Research and Extension Center gin to determine gin turnout, lint percentage
                  and seed weights. Results will be tabulated by locations and statistically
                  analyzed using analysis of variance and mean separation procedures.
                  Summaries of data will be done by individual locations and over locations.
                  Verticilium wilt incidence will be evaluated in 25 plants per field replication in
                  the as many varieties as time and labor allows.

                  As we did following the 1999 season, results of the trials will be reported in
                  winter meetings of the UCCE Specialist and Farm Advisors, and will be
                  printed in the CA Cotton Review (January or February issue) as well as in
                  county newsletters and meetings. Plans for 2000/2001 are to include the
                  yield, final mapping and lint quality data in a web site that will be more
                  accessible for grower and industry review, with this information posted as
                  soon as possible after February 1 each year. This posting on a UCCE web
                  site was initiated in 2000.

                  Following is some information collected in the Advanced Strains trials in
                 1999 (Table 1 for yield summaries, Table 2 for lint quality summary). This is
                 similar to the type of information we will continue to collect in 2000 and 2001.
                 The data shown concentrates on yield and quality information, and does not
                 show data collected in mapping work, Verticillium wilt evaluations or
                 evaluations of earliness and ease of defoliation (that work will be reported
                 elsewhere for the 2000 data after analyses are complete.

        Project: 46 Upland Cotton Varietal Response to Short-Season Versus Long-
                 Season Management Practices
Project Leader: Bob Hutmacher, UCCE Extension Agronomist, Shafter REC & Agronomy &
                 Range Science, UC Davis
                 Steve Wright, Farm Advisor, UCCE Tulare County
                 Brian Marsh, Superintendent, Shafter REC and Farm Advisor, UCCE Kern

                Cooperators: Mark Keeley, Raul Delgado, Scott Perkins, Lalo Banuelos
     Objective: The introduction of some potentially widely-different varieties which were
                developed in environments outside of CA in most cases represents a real
                challenge in terms of identifying the most suitable management practices for
                best results under SJV conditions. These "newly-available" varieties are now
                available in CA under the designation "CA Upland". These varieties in many
                cases represent an opportunity of unknown proportions to CA cotton
                growers. Tests on grower fields in 1998 were largely planted very late under
                the governor's emergency exemption, so may or may not truly represent the
                potential of these varieties in improving grower profitability. It was considered
                vital that we get some UCCE testing programs underway in 1999 and
                beyond that will begin to answer some questions regarding management
                approaches with these varieties. Information is needed by the growers to
                make some hard decisions on variety choices. It is important that at least
                some of these tests occur under well-controlled conditions so that
                assessments can be made of the likely range of varietal performance in both
                yield and quality characteristics. Varietal evaluations important to the
                growers and industry include not only yield, but quality characteristics of the
                new variety choices with potential to impact both the reputation of CA SJV
                cotton and potentially the impact of the premium price now paid to growers of
                "Approved Acala" varieties approved by the San Joaquin Valley Cotton

                 The evaluations begun at the WSREC and Shafter REC in 1999 began an
                 evaluation of the impact of combinations of two planting dates, two irrigation
                 treatments and two growth regulator regimes on growth, yield and quality
                 responses of three cotton varieties (one approved SJV Acala and two CA
                 Upland varieties) representing some of the range of expected differences in
                 growth habit and estimated maturity. Data from this project will eventually be
                 described in the CA Cotton Review, and will also be mentioned in crop
                 advisory updates printed in handouts at Production meetings. Data will also
                 be presented at cotton field days at both the Shafter REC and West Side
                 REC. Project results will also be featured in oral presentations at the Cotton
                 Workgroup meetings in December, and in the session and Proceedings of
                 the jointly-sponsored CA Cotton Growers Association Winter Meeting /
                 UCCE Winter Production Management Seminar when adequate data is
                 available for presentation.
Protocol Used:
Some of these varieties can be classified as having the potential to be "early-
maturing", "medium season", or "full-season" varieties. While years like 1998
can demonstrate the utility of "short-season" varieties in making a good crop
within the constraints of a limited growing season, there are many years in
CA where the growing season duration is much greater than in 1998. We feel
that it is important to identify the "plasticity" of some varieties representative
of part of the range of growth habits, maturity classes under management
practices covering a range of strategies, including:

(a) conditions typical of a shorter growing season requiring a more
compressed fruiting period (perhaps more water stress and earlier or higher
rates of growth regulator)
(b) long-season management where goals may be to build a larger
framework / more fruiting sites, with a different management scheme
involving less water stress / more growth regulator application which are
started later, and, if boll load warrants, consideration of additional foliar
fertilizer applications during flowering to "push" the plant under long-season
(c) with two planting dates, two irrigation / fertilizer regimes and two growth
regulator treatments and the eight combinations (2 x 2 x2 ), there can be a
range of conditions in between the extremes mentioned in (a) and (b) above

1999 Results/2000 experiment.
In both 1999 and 2000, this test was replicated at both the Shafter and
WSREC locations. Both fields were planted on 40 inch row spacing. Trials
initiated in 1999 at the West Side and Shafter REC's begin to look at the
impact of combinations of two planting dates (mid-April versus early May),
two irrigation treatments and two growth regulator regimes on growth, yield
and quality responses of three cotton varieties (one approved SJV Acala
(Maxxa) and two CA Upland varieties (Germains GC-204 (early-mid-
maturity) and DPL Nucotton 33B (mid-maturity)). These varieties represent at
least some of the range in expected differences in growth habit and
estimated maturity across the CA Upland varieties when compared with an
Acala standard.

The following points are worth noting in the 1999 results:

· Irrigation treatments with variable irrigation amounts and timing were
achieved at both field research sites, resulting in different timing and degrees
of water stress across treatments (IRRIG TRT #1 was irrigated at the
standard -16 bars first irrigation / -18 bars subsequent irrigation for leaf water
potentials in UCCE recommendations) - (IRRIG TRT #2 was irrigated the
same for the first irrigation, but subsequent irrigations were delayed to
achieve about 2-3 bars lower leaf water potential prior to irrigations)
· Growth regulator treatments differed in the timing and amount of mepiquat
chloride applications, based upon the use of 4th-5th internode length
measurements for the timing in short-season management versus first bloom
timing in longer-season management treatments
· Plant monitoring data showed some differences in factors such as plant
height and node development across treatments, with varietal interactions,
but the data has not been fully analyzed at the time of preparation of this
· Differences in yield were seen across treatments, with the most consistent
yield improvements with the earlier planting date, with planting densities
                 approximately 40,000 to 45,000 plants per acre instead of 75,000, and with
                 earlier irrigation termination (under 1999 conditions).

                 Results from primary treatments for each variety at the Shafter REC and
                 West Side REC locations are shown in Table 1, showing lint yield averages
                 for all three varieties individually. Data for the West Side REC location
                 showed more dramatic differences with planting date, irrigation and plant
                 density treatments than at the Shafter REC location. Lint yields were
                 generally significantly better with the earlier planting date in all three
                 varieties, and with the delayed irrigation in the two CA Uplands but not with
                 Maxxa. Plant density impacts were more complicated, with higher densities
                 resulting in reduced yields in the earlier planting date treatments at high yield
                 locations, but in similar or higher yields under the lower yield potential
                 conditions at Shafter or with delayed plantings.

                 2000 project results.
                 Very good plant populations were achieved in both field trial locations this
                 year, which provided adequate numbers of plants to allow thinning to the two
                 planned plant populations (40,000 to 45,000 plants per acre versus 70,000 to
                 75,000 plants per acre). For 2000, the three varieties utilized in the study
                 include Maxxa (an Acala standard variety for comparison purposes),
                 Germain's GC-204 (a relatively short-season/mid-season variety - changed
                 from 1999); and DPL Nucotton-33B (a mid-season variety grown on quite a
                 few acres in CA in recent years).

        Project: 52 Narrow-Row (Double-Row 30 Inch and Double-Row 40 Inch) by
                 Variety Trial
Project Leader: Bob Hutmacher, UCCE Extension Agronomist, UC Shafter REC & Agronomy
                 & Range Science, UC Davis
                 Bill Weir, Farm Advisor, UCCE Merced County
                 Brian Marsh, Superintendent, Shafter REC and Farm Advisory, UCCE Kern
                 Cooperators: Mark Keeley, Raul Delgado, Scott Perkins
     Objective: Studies were initiated in 1999 and continued in 2000 to evaluate the
                 responses of three cotton varieties (two CA Upland and one Acala) to
                 several different combinations of row spacings and plant density. These
                 studies were initiated as an extension of studies initiated by Dr. Bill Weir and
                 representatives of San Juan Ranch (Daniel Burns) and Bowles Farms (Ken
                 Van Loben Sels) at farm sites in Merced County. Preliminary studies have
                 been done in 1998, 1999 and 2000 on private farms in Merced and Madera
                 County, and these sites at the West Side and Shafter Research and
                 Extension Centers were set up as locations for trials under conditions where
                 a fairly high level of control over inputs and pest control measures could be
                 handled. Shown in Table 1 is the 1999 data at the West Side REC, while
                 Table 2 has 1999 data for the Shafter REC location.

                 1999 Results.
                 In the West Side REC trial in 1999, the plant populations achieved were
                 lower than the design plant populations. In the 1 row / bed planting
                 configuration, the planting rate called for a final plant population of about
                 45,000 plants per acre, while an average of 33,100 plants per acre were
                 achieved (averaged across all three varieties). In the 2 row per bed
                 configuration where a final plant population of 75,000 plants per acre was the
                 target population, an actual average population of 54,700 was achieved.

                 At the Shafter REC trial in 1999, the plant populations achieved were also
                 somewhat lower than the design plant populations, although not as low as at
                 the WSREC location. In the 1 row/bed planting configuration, the planting
                 rate called for a final plant population of about 45,000 plants per acre, while
                 an average of 41,500 plants per acre were achieved (averaged across all
                 three varieties). In the 2 row per bed configuration where a final plant
                 population of 75,000 plants per acre was the target population, an actual
                 average population of 59,200 was achieved.

                 In both 1999 and 2000, the double-row and single-row plantings at the West
                 Side REC location were all on 40-inch beds, while the trials done at the
                 Shafter REC were on 30-inch rows. All of the field trials in the Merced County
                 grower locations were on 30-inch beds. In the 1999 trials at Shafter REC,
                 double-row plots out yielded single-row in each variety by 8% or more, while
                 yield differences were not significant at the West Side REC site.

                 2000 Results.
                 Identical field setups were used for these trials in 2000, and data collection
                 and plans for harvest and lint quality evaluations are the same as in 1999.
                 Final plant mapping will again be done to help analyze affects of treatments
                 on boll distribution on a plant basis. Results of these studies will be reported
                 either in CA Cotton Review articles or at the Winter UCCE Production
                 meeting held annually in February of each year.

        Project: 54 Agronomic Test of Improved Fiber Quality Pima Germplasm
Project Leader: Richard Percy, Research Geneticist USDA-ARS, 602-379-4221
                 Bob Hutmacher, UCCE Extension Agronomist, UC Shafter REC & Agronomy
                 & Range Science, UC Davis
     Objective: Sources of superior fiber strength and length exist within extra-long staple
                 Gossypium barbadense germplasm. However, these sources lack heat
                 tolerance, are later maturing, have lower yield potentials, or are otherwise
                 unadapted to the southwestern United States. A breeding project was
                 initiated several years ago to incorporate superior fiber length and strength
                 into a heat tolerant, earlier maturing, higher yielding Pima background, and
                 to widen the genetic base of Pima germplasm. A Sea Island cotton, St.
                 Vincent, and an Egyptian cotton, Giza 70, were hybridized with an early
                 maturing Pima strain, P62. Progeny of these hybridizations were
                 intercrossed among themselves and crossed to another source of high fiber
                 strength, 8810. Selected progeny of this second round of hybridization are
                 now being evaluated in replicated testing to identify superior lines for release
                 to private and public breeding programs.

                 In 1999, ten progeny lines were evaluated in replicated tests at Maricopa and
                 Safford, AZ. Preliminary analyses of results indicate that the lines possess
                 fiber that is 4-5 g/tex stronger and a tenth of an inch, or more, longer
                 (approx. 1.48-1.55 inches) than Pima S-7. Fiber yield among the 10 lines
                 varied from 110% to 66% of Pima S-7 when averaged over the two locations.
                 The majority of lines tested were equal to, or shorter than, PS-7 in plant
                 height. All lines exhibited heat tolerance superior to the Sea Island St.
                Vincent and Giza 70 parents and comparable to PS-7 at Maricopa, AZ.
                Some deficiencies were noted within the lines, among these being lower lint
                percentages. Two or three of the lines exhibit tight, non-fluffed lint within the
                boll and weak stems. All lines are being evaluated for yield, fiber quality, and
                agronomic characteristics at Shafter, CA in 2000.

                The best three or four germplasm lines will be determined using data
                collected at the three test sites in Arizona and California in 1999 and 2000.
                The USDA-ARS, the Arizona Agricultural Experiment Station, and the
                California Agricultural Experiment Station will jointly release the best lines to
                public and private breeding programs in the winter of 2001.

       Project: 55 Root-Knot Nematode Management in Cotton
Project Leader: Peter B. Goodell, IPM Advisor, Statewide IPM Project, Kearney Ag Center
                Phillip A. Roberts, Professor, Nematology, UC Riverside
                Chuck Haas, SRA, Kearney Ag Center
     Objective: Cotton is susceptible to attack by root-knot nematode, causing an estimated
                1.2% loss of yield (25,000 bales) in 1999. Chemical control has been limited
                through the restrictions on fumigants and the lack of long-term control with
                contact nematicides. Our project has investigated non-chemical alternatives
                to management of root-knot nematode in Acala cotton and is developing
                information on the impact of root-knot nematode on Pima yield.

                Root-knot nematode can be managed in cotton using non-chemical
                approaches, specifically rotation to non-hosts and use of host plant
                resistance. We demonstrated that rotation with alfalfa or black-eye bean
                reduced root-knot nematode populations (Figure 1) and raised yields
                compared to continual Maxxa rotations (Figure 2).

                The introduction of root-knot nematode resistant Acala cotton in 1996
                provided a new tool in the management of this pest. During the period 1997
                through 1999 we demonstrated the value of NemX cotton in protecting yield
                (Figure 3). In addition, the resistant variety does not allow the population to
                build during the growing season.

                The impact of root-knot nematode on Pima production is not very clear. Pima
                cotton (Gossypium barbadense) is a different species from Acala upland
                cottons (G. hirsutum) and information about this Pima and root-knot
                nematode is limited.

                We have initiated trials comparing two varieties under different root-knot
                nematode populations. These trials have already demonstrated that Pima S7
                yield is as susceptible as Maxxa and allows populations to build during the
                growing season (Figure 1). Our investigations will also look at the interaction
                of Fusarium, root-knot nematode, and Pima cotton.

       Project: 83 Development of High Yielding, Pest Resistant Blackeye Bean
                Varieties for California
Project Leader: Jeff Ehlers, Botany and Plant Sciences, UC Riverside (909) 787-4332
                Tony Hall, Botany and Plant Sciences, UC Riverside (909) 787-4405
                Blake Sanden, UCCE Kern County (661) 868-6218
     Objective: Introduction
                Blackeye bean is an important rotation crop of cotton systems in California
                with production on about 40,000 acres in the State, most of which is in the
                San Joaquin Valley. 'Blackeyes' are the largest single market class of dry
                beans produced in California. Varieties with high yield, heat tolerance,
                excellent grain quality, and resistance to root-knot nematodes, Fusarium wilt,
                lygus bug and cowpea aphid are needed in order for blackeye production to
                remain competitive with lower-cost producers in Texas and elsewhere. As
                there are no private companies breeding blackeyes in the US, so it is
                appropriate that the University of California be involved in the genetic
                improvement of this crop. There are no private companies breeding
                blackeyes in the US, so it is appropriate that the University of California be
                involved in the genetic improvement of this crop. The University of California,
                Riverside (UCR) has a breeding program to develop improved blackeye
                varieties and complimentary production systems for California growers.
                Since 1995, the Shafter Research and Extension Center has been a key
                testing site for evaluation of breeding lines being developed by the UCR
                program, and for evaluation of agronomic practices (e.g. row-spacing x
                variety trials) and of the heat tolerance and delayed leaf senescence traits.

                 Varietal development and testing: 'California Blackeye No. 27' (CB27),
                 developed by the UCR blackeye breeding program under the experimental
                 designation H8-8-27, was released in May 1999 following several years of
                 field performance testing at the Shafter Research Station and other
                 locations. CB27 possesses high yield potential, excellent grain quality and
                 also heat tolerance, broad-based resistance to root-knot nematode
                 (Meloidogyne incognita and M. javanica) and resistance to two races of
                 Fusarium wilt (Fusarium oxysporum) (Table 1).

                 We consider the Shafter Research Station to be a key site at which to
                 evaluate yield potential of blackeye lines under development by the breeding
                 program at UCR. In 2000, we are evaluating 32 new blackeye breeding lines
                 for yield potential and seed quality in replicated trials, and have a breeding
                 nursery with 140 lines from which selections will be made.

                 Effects of heat tolerance and delayed leaf senescence (DLS) traits on
                 single-flush yield and agronomic performance: The DLS and heat
                 tolerance traits in cowpeas were discovered and described by this project
                 some years ago. The DLS trait enhances plant survival under certain stress
                 conditions that cause many plants of non-DLS lines to die after the first flush
                 of pods is produced ('early cut-out'). Consequently, the DLS trait can
                 increase yields of long-season blackeye crops. Both heat tolerance and DLS
                 have now been incorporated into advanced blackeye breeding lines, but
                 assessments of the traits individual and combined effects on yield in a wide
                 genetic background under field conditions had not been investigated. In this
                 experiment, conducted at both Riverside and Shafter, we compared the first-
                 flush grain yields and other agronomic traits of 40 lines, ten lines each of the
                 following four types: heat tolerant with DLS, heat tolerant without DLS, heat
                 susceptible with DLS, and heat susceptible without DLS. All lines were
                 derived randomly from a single cross between a heat tolerant, non-DLS
                 parent (H8-9) and a heat susceptible, DLS parent (8517) and had been
               developed and characterized for either expression/non-expression of DLS
               and heat tolerance in several evaluations over the last four years.

               The interaction of the DLS and heat tolerance traits was not significant for
               either yield, harvest index, pods per peduncle, 100 seed weight, or seeds per
               pod. Heat-tolerant lines produced substantially greater average yields than
               the heat-susceptible lines at the hotter location (29.6 vs. 21.6 sacks/ac at
               Shafter) and similar yields at Riverside. Heat-tolerant lines also had a higher
               harvest index, more pods per peduncle, and greater seed weight than heat-
               susceptible lines. Average grain yields of lines with DLS were 3-4 sacks/ac
               lower than senescent lines, suggesting there is a yield penalty on the first-
               flush. This penalty is more than made up for in double-flush production fields
               where CB46 cuts-out and the DLS lines consistently produce two flushes of

               Evaluation of growth habit x production system interactions. We
               completed a two-year study in 1999 at the Shafter REC to evaluate yield
               responses of new compact and viny plant type blackeye breeding lines and
               varieties in the production systems used by blackeye growers in San Joaquin
               Valley. Growers typically use one of three planting systems, i.e. single
               planted row on 30" raised beds, single planted row on 40" raised beds, or
               two planted rows on 40" raised beds. Within-row spacing is generally 3-4
               plants per foot, resulting in different total plant densities for each system.
               Past research, conducted before the development of compact blackeye
               varieties such as CB46 and CB27 had not shown yield response to changes
               in planting density or row spacing. With the development of compact
               blackeyes, a re-examination of variety x row spacing effects was warranted.
               We evaluated the agronomic performance of 6 lines with contrasting plant
               habit (3 compact lines- CB46, CB27, and H36, and 3 viny lines- CB5, H8-8-
               1N, and UCD 8517) under the three planting systems used by growers in the
               San Joaquin Valley. Plots were harvested after a single pod flush had
               occurred (about 100 day growing season). Briefly, compact lines produced
               higher grain yields in both years (two year avg. yield of 3076 lb/ac) and had
               higher harvest indices (two year avg. of 48 %) than viny lines (two year avg.
               yield of 2698 lb/ac) and harvest index (42%) over the three production
               systems. The compact plant type appears to be higher yielding as a
               consequence of better partitioning of assimilates into grain. In both years,
               compact varieties produced their highest yields (two year avg. yield of 3226
               lb/ac) at the intermediate density (single-row 30" bed) and high density
               (double-row 40"bed) systems, while viny varieties produced their highest
               yields at the lowest density (single-row 40"bed) spacing (two year avg. yield
               of 2817 lb/ac).

               Future Plans
               The Shafter REC provides a representative high-yielding environment to test
               breeding lines being developed by the UCR breeding program. We hope to
               continue this effort as well as agronomic/management studies that
               compliment new blackeye varieties that are being developed.

        Project: 84 Potato Late Blight Screening Nursery
Project Leader: Ron Voss, Vegetable Specialist, UC Davis
                 Joe Nunez, UCCE Kern County
     Objective: Problem and Significance: Late blight of potatoes was a major problem in
                Kern County spring potatoes in 1994, 1995, and 1998. This has become a
                problem in the past few years not only for Kern County potato growers, but
                for potato growers worldwide. New strain of the fungus has entered Kern
                County, just as it has in other parts of the country. The introduction of the
                new strains of Phytophthora infestans has made the control of late blight
                more difficult.

                The old strain, A1, was satisfactorily controlled with the use of systemic
                fungicides. The presence of the newly introduced A2 strain has hampered
                control of late blight because it has shown resistance to the standard
                fungicide treatment. The presence of both mating types has also produced
                new genetic recombinations that are superior in their ability cause disease.
                Besides being resistant to the previous standard late blight fungicide, these
                new strains are more aggressive and cause infection over a wider range of
                environmental conditions. The new strains found in Kern County potato fields
                are superior from the previous strains that growers had to deal with in their
                ability to overwinter, produce many generations of asexual spores
                (sporangiaspores), resistance to metalaxyl, and ability to cause infection at
                higher temperatures. Because of the increased virulence of the new strains
                growers need to adopt new control strategies.

                Genetic resistance has been one area of late blight control strategies that
                has been ignored in the past. This has probably been largely due to the fact
                that highly efficacious fungicides were available. With the introduction of the
                new strains however, identifying potato varieties that demonstrate resistance
                or tolerance to late blight has become increasingly important as a method of
                reducing pesticide use. A late blight screening nursery has been conducted
                at SREC since 1998 to identify commercial and breeding lines that may have
                some genetic resistance. These studies have shown that differences do exist
                among some of the commercial lines and breeding materials.

        Project: 86 Importation of Peristenus spp. for the Biological Control of Lygus
Project Leader: C. Pickett, J. Ball, D. Mayhew, K. Casanave, U. Kuhlmann , D. Coutinot ,
                 L. Ertle , and K. Hoelmer
                 Biological Control Program, California Dept. of Food & Agriculture, 3288
                 Meadowview Road, Sacramento, California

                  CABI Bioscience, Delemont, Switzerland
                  USDA-ARS European Biological Control Laboratory, Montpellier, France
                  USDA-ARS Newark, Delaware
     Objective: Lygus hesperus is the number three ranked pest nationwide on cotton and a
                key pest of cotton in California. New, imported parasitoids capable of
                attacking L. hesperus nymphs could significantly reduce early season
                populations infesting cotton by attacking overwintering populations of this
                pest residing in alfalfa and other non-crop plants within the cotton
                agroecosystem. Past and present surveys have found parasitism completely
                lacking in nymphs of Lygus hesperus sampled from central California grown
                alfalfa. An attempt to establish nymphal parasites of Lygus hesperus in
                California in the 1970's failed, either due to poor syncronization between host
                and parasite or loss of habitat. Bill Day and others in eastern United States,
                however, have successfully imported a nymphal parasitoid that attacks
                Lygus lineolaris, a close relative to Lygus hesperus. Peristenus digoneutis
                has increased parasitism from 15% to 50% two years following
                establishment. Lygus numbers have decreased by 75% in alfalfa. We
                propose importing exotic species of Peristenus spp. collected from Lygus
                infesting alfalfa in southern Europe. Populations of Peristenus collected from
                areas with climate similar to central California and released into alfalfa
                managed for parasitoid survivorship will maximize their chances for
                permanent establishment.

                 Foreign exploration has been conducted in Europe over the past 3 years.
                 Three populations of adult and immature Peristenus stygicus (i.e.,
                 parasitized nymphs) have been released multiple times into each of 7
                 release sites in central California, from Kern to Yolo county. Three sites are
                 in the Sacramento region and four in the southern San Joaquin Valley. The
                 alfalfa fields are either small plots maintained specifically for our project, or
                 commercial forage alfalfa. One of these is at the UC/USDA Shafter Field
                 Station. The first releases were made in the Sacramento region summer
                 1998. The first releases of parasitoids at the southern sites occurred this
                 summer, beginning in April.

                 This year a total of 12,269 adult parasitoids and 15,900 exposed nymphs
                 were released in the 7 fields. Peristenus cocoons were recovered in May
                 from our Sacramento site, showing the population released in summer 1999
                 successfully overwintered and persisted in our plot. They were recovered in
                 higher numbers in an August sample. Parasitoids have been recovered this
                 August from 3 of 7 release sites. Recoveries have been found in 3 out of 4 of
                 our own managed alfalfa plots. A surprisingly high level of parasitism (24%;
                 n=25) was recorded at the UC Kearney Agriculture Ctr. Site where
                 parasitoids were released for the first time this summer.

        Project: 88 Nightshade Control in Blackeye Beans
Project Leader: Dave Bayer, Professor, UC Davis
                 Ernie Roncoroni, SRA IV, UC Davis, (530) 752-2173
                 Blake Sanden, UCCE Kern County
                 Carol Frate, UCCE Tulare County
     Objective: Tall morningglory (Ipomoea purpurea) and ivy-leaf morningglory (Ipomoea
                 hederacea) continue to be serious problem in some areas of the blackeye
                 bean growing areas of the Southern San Joaquin Valley and is appearing in
                 more fields each year. Both tall and ivy-leaf morningglory over grows the
                 blackeye bean plants making harvest difficult and reduces blackeye bean
                 yields in areas of heavy infestation. Current registered herbicides for use in
blackeye beans are not satisfactorily controlling either species of

A Pesticide Research Authorization from the State of California for weed
control trials in blackeye beans allowed the use of non-registered and
experimental herbicides such as Frontier, Authority, Pursuit and Raptor to be
evaluated alone and in combination with currently registered herbicides for
weed control. The Shafter Research and Extension Center site is of major
importance because it is located in the major blackeye bean growing area.

The field was divided into four 40-inch rows by 25 feet long plots and
replicated 3 times in a randomized complete block. Preplant incorporated
treatments (Table 1.) were applied May 22, 2000 using a hand held CO2
backpack sprayer. Herbicides were applied, to the entire plot, in 20 gallons of
spray solution per acre using 80015 nozzles at 30 psi. Immediately after the
last herbicide application all beds were reshaped using a power incorporator
bed shaper. Two rows of 'California Blackeye 27" were then planted per 40
inch bed. The post plant surface treatments of Authority or Aim were then

Prior to the post emergence treatments on June 22, 2000 all plots were
evaluated for morningglory control. Post emergence treatments were also
made in 20 gallons of spray solution per acre. Herbicides were applied over
the top of the blackeye beans to evaluate both morningglory control and
injury to the beans. A second evaluation was made August 2, 2000. Attempt
at a third evaluation on August 24, 2000 showed that our individual plot size
was too small and that morningglory from one plot had spread throughout
surrounding plots.

The preplant treatments of Sonalan and Dual Magnum + Prowl (Table 2.)
gave satisfactory early control of the morningglory. The addition of Pursuit +
Crop Oil Concentrate to Dual Magnum, Dual Magnum + Prowl or Frontier
gave added morningglory control. Only Raptor at the .047 lb ai + 1 quart of
COC per acre caused any visual damage to the blackeye beans. This injury
was noted as a loss of early flowers, which delayed the blackeye pod set.
The soil active herbicides such as Authority and Pursuit were tested at
reduced rates for weed control and to reduce herbicide residuals.

At the end of the normal growing season the blackeye beans will be
harvested and then the area will be tilled and planted to selected winter
vegetable and agronomic crops to evaluate carry-over of the soil active
herbicides in Kern County soil.

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