INSIDE Sweet Corn Spacing and Light Utilization

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					                                                                                                Vegetable Crops Edition
                                                                                                            May 6, 2009

          Plant & Pest advisory    A Rutgers Cooperative Extension Publication

                                                                 Sweet Corn Spacing and
                                                                    Light Utilization
                                                   Ray Samulis, Burlington County Agricultural Agent

                                                               weet corn yields are controlled by many different factors
                                                               including but not limited to plant genetics, fertility, irrigation,
                                                               and pest control. There are, however, other factors such as
                                                   light utilization, orientation to the sun, and proximity to adjoining plants
                                                   that are often overlooked as contributors. Research I conducted during
                                                   the 2008 growing season investigated the effectiveness of sunlight pene-
                                                   tration into the plant canopies. This study was conducted using a photon
                                                   light meter which was able to measure the light level at various parts of
                                                   the stalk and distances from plant to plant. This specialized instrument
                                                   measured light levels from 400 to 700 nanometers which equates to the
                                                   most active photosynthetic light spectrum. Photosynthesis is of course
                                                   the name of the game in producing any type of crop because it is this
                                                   biologic process that produces the sugars, starches, proteins, fibers etc.
                 INSIDE                            that we harvest in the final crop product.
                                                        When light was measured from the top of the stalks to the bottom,
                                                   levels ranged from more than 1900 umol at the top to less than 150
                                                   umol at the base of the plants where foliage was most dense. An old
Sweet Corn Spacing and Light                       time planting system, hill planting, was also tested where 5-6 seeds are
Utilization ...................................1   planted together and the space between hills made wider. This was proba-
                                                   bly done to facilitate cross cultivation of fields before herbicides were avail-
Drip Irrigation System                             able. The measured light levels were not much different than the traditional
Maintenance ...............................2       spacing and levels ranged from 1939 umol at the top to 138 umol at the
                                                   bottom. Data was also taken measuring light at varying distances from the
Pest Notes ...................................3    stalks. It seems that the range of light was 188 umol @ 4” from the stalk to
                                                   more than 900 umol once you moved more than 8” from the stalks.
Vegetable IPM Update .............3                     I concluded from this study that:
                                                   1) Light levels under cloudy conditions resulted in a loss of more than
Vegetable Disease Update .......4                      2/3 of the available photosynthetic light.
                                                   2) The sphere of influence of the stalks caused by shading light from
Strawberry Notes ......................6               adjoining stalks greatly diminished once you moved beyond 8” from
                                                       the plants. This confirms that 8” spacing is what most growers con-
EQIP Organic Farming                                   sider good plant spacing in most of their sweet corn fields.
Assistance ...................................7    3) Plant tops were exposed to 7-9x more light when compared to the
                                                       plant bottoms. This would suggest that growers should be paying
Weekly Weather Summary ......7                         more attention to the condition of the upper foliage and not just
                                                       worry about the older tissue for example in estimating rust levels.
                                                                            See Corn Spacing on page 2
Vol. 5 No. 7                                                                                                              Page 
         Drip Irrigation System                                       Other reasons for clogged emitters can be from
                                                                calcium carbonate and iron ochre. Calcium carbonate
             Maintenance                                        build up in lines can result in two ways; evaporation of
                                                                water leaving salts behind or changes of solubility due to
Michelle Casella, Gloucester County Agricul-
                                                                change of solution characteristics (temperature or pH).
tural Agent                                                     Generally evaporation is not a problem in drip systems,
                                                                it is more so due to chemical changes (increase in pH)

    W        ith the use of drip irrigation systems so com-
             mon in New Jersey’s vegetable industry, it is
important to remember to conduct proper maintenance
                                                                in the water solution or increase in water temperature.
                                                                When water pH increases and calcium carbonate pre-
                                                                cipitates, clogging of the emitters can occur. To clean
for optimum use and to reduce down-time of the systems          emitters, acid injection is generally recommended. There
during the growing season. For starters, the filtration unit    are two fertilizers that can be used for this purpose. An
is the most important part of the drip irrigation system.       acid formulation of nitrogen fertilizer (N-phuric) can be
This is one area that should not be neglected. A poor           used for pH control and nitrogen fertilizer at the same
filtration system or not maintaining a filtration system is     time. Additionally, phosphoric acid (a form of phos-
the main cause of drip irrigation system failure. Clogged       phorus fertilizer) is another product that is used to flush
emitters occur when irrigation water is not properly            out drip lines. Since these products are both acids they
filtered and particulates end up in the drip tubes. Addi-       can be corrosive to steel and aluminum pipes, but are
tionally, flushing out of drip lines should also be a part of   noncorrosive to pipes made of PVC or PE. Adding acid
a regular maintenance program to ensure efficient, even         to the system can also keep iron in solution so it does
water distribution through the drip irrigation system.          not precipitate and cause clogging of emitters, but this
      Particles that can clog emitters are things like sand,    is only successful when iron is at very low concentra-
organic particles, calcium carbonate (lime), and iron           tions. Iron becomes a bigger problem when there is an
ochre (slime). Sand in the system often comes from wells        interaction with iron and bacteria. When this occurs iron
that pull up sand particles with the groundwater. Screen        becomes surrounded by filamentous bacteria forming a
filters usually are used to remove sand in drip irriga-         slime or gel that clogs emitters. In this case chlorination
tion systems using well water. Screen filters should be         is used to oxidize the iron by use of a shock treatment,
cleaned by back-flushing when the pressure drop across          like used for organic particulates.
the filter increases by 3 to 5 psi, or as recommended by              Even with diligent efforts in maintaining drip ir-
the manufacturer. Some systems offer an automatic flush-        rigation system clogs may still occur. Keeping on top of
ing system for screen filters called “spin filters”. These      maintenance, frequently checking flow meters and pres-
are continuous flushing units that constantly remove            sure gauges, and checking irrigation water quality are
particles while the system is running. For finer particle re-   ways to maximize efficiency of the system.
moval, like organic materials, sand media filters are most      References:
often used. Media filters should be back-flushed when           Alam M., T.P. Trooien, F.R. Lamm, D.H. Rogers. 2002,
the pressure drop reaches about 10 psi, or as recom-            “Filtration and Maintenance Considerations for Subsur-
mended by the manufacturer. The use of two filters side         face Drip Irrigation Systems” Kansas State University
by side allows for constant running of the system when          Benham. B. and B. Ross. 2002. Filtration, Treatment, and
                                                                Maintenance Considerations for Micro-Irrigation Sys-
back-flushing one filter so the other filter can continue to    tems. Pub. 442-757. Virginia Cooperative Extension. o
run the system. Automatic flushing is generally required
on media filtration systems. Some manufacturers recom-                           Corn Spacing from page 1
mend the use of a screen filter after the media filter as a     4) As a side observation, where plants spacing’s were
back up for filtration in case of media filter failure.            very tight, adequate irrigation seemed to overcome
      Since many microbiological organisms live in ir-             some of the crowding effects. In other words, where
rigation water, Chlorine injection is commonly used to             irrigation was inadequate, the crowded ears were
prevent the accumulation of biological material in drip            much smaller and where irrigation was adequate the
irrigation systems. In systems where these organisms are           ear size was near normal despite crowding.
a problem, constant injection of 1 to 2 ppm of chlorine              Spacing is an important grower decision that will de-
should be injected continuously. If microbiological             termine the overall yield of the crop. Wide spacing more
organisms have not been a problem then this step is not         than 8” however does not appear to improve light utili-
necessary. However, if a problem does arise and emit-           zation and yields in sweet corn fields. Be sure to keep a
ters become clogged, a chlorine shock treatment may be          careful eye on the condition of the upper foliage on your
needed. A shock treatment uses a concentrated amount            stalks. Look for color indicative of adequate N levels
of chlorine of 10 to 30 ppm and the solution is left in         and look for other possible nutrient problems. This upper
the line for an amount of time to clean out the lines and       area of the stalk is exposed to the highest photosynthetic
emitters. Time of treatment is determined by the severity       light levels present in your fields and will subsequently
of the clog.                                                    contribute to your total sweet corn yield. o
Page 2                                                                                                      Vol. 5 No. 7
                        Pest Notes                                        Vegetable IPM Update
Gerald M. Ghidiu, Ph.D., Specialist in Vegetable Ento-                   Kristian Holmstrom, Research Project
mology                                                                   Coordinator II, Vegetable IPM Program

Section 18 Approved for Ponco on bulb onions,
bunching onions and leeks in New Jersey.                                     M       ost of the RCE Vegetable IPM black-
                                                                                     light network has been deployed,
                                                                         and as yet, no European corn borer (ECB) or
     The Federal EPA approved a Section 18 Label for NJ for the use
of Ponch 600 as a seed treatment on bunching onions, bulb on-            corn earworm (CEW) have been caught. It
ions and leeks to protect against onion maggot. Poncho contains          is likely that we will not see either of these
the active ingredient clothianidin, and has shown to be effective        pests until warmer and drier weather be-
against onion maggot, seedcorn maggot and onion thrips when ap-          comes more prevalent.
plied as a seed treatment in onion trials at the Geneva Experiment             Cool, wet weather has limited flea beetle
Station, Cornell University, during the past several years.              infestations on new cole crop plantings. As
     Poncho must be applied to all onion and leek seed with a            the weather warms, these pests will become
film-coating or pelleting system. It can be applied at rates of 1.38     active. Flea beetles impact certain crops
fl oz/lb seed for bulb on-                                               like mustard greens and arugula much more
ions, 1.24 fl oz./lb seed                                                seriously than cabbage, and these crops
for bunching onions,                                                     should be scouted at least weekly. Check 5
and 1.61 fl oz/lb seed for                                               consecutive plants each in 10 random loca-
leek.                                                                    tions throughout the field. Consider treating
                                                                         if beetles are found on approximately 50% or
     This exemption is
                                                                         more plants and feeding damage is apparent.
approved as of May 1,
                                                                         Remember that warm weather will increase
2009 and remains in
                                                                         beetle activity.
effect until May 1, 2010.
A final report will have                                                       Several northern New Jersey tomato high
to be made concern-                                                      tunnels have been established, and as yet
ing acres treated with                                                   show no signs of pest problems. The typical
Poncho-treated seed to the                                               pest in these tunnels is two-spotted spider
EPA after this expiration,                                               mite (TSSM). While checking plants, be sure
so please keep accurate                                                  to look as older leaves for signs of “mite-stip-
records of total lbs treated                                             ple” or bright white pin-spots on the upper
seed you use and acres                                                   leaf surface. An examination of the under-
planted with treated seed.                                               side of these leave will generally reveal a few
A copy of the Section 18                                                 TSSM. As they increase, the spots coalesce,
Label has been forwarded                                                 and leaves begin to yellow. Often TSSM
to the county agricultural                                               produce webbing as they become more nu-
agents.                                                                  merous. If TSSM appear while the weather is
                                                                         still reasonably cool (before June), they may
Strawberry Mites                                                         be controlled effectively with the predatory
     Dr. Wyenandt reports                                                mite Neoseiulus fallacis. An internet search
that a few growers have spider mites that overwintered in high tun-      of this predator will return several commer-
nel strawberries. Many effective miticides are available for use on      cial sources for purchase. Generally one vial
strawberries, including abamectin (AgriMek), bifenzate (Acramite),       per tunnel is more than sufficient to manage
etoxazole (Zeal), fenbutatin-oxide (Vendex), hexythiazox (Savey),        TSSM for as long as is necessary. Mist the
and spiromesifen (Oberon). Also, several pyrethroids are avail-          plants lightly with water so that the bran that
able that may also help keep mite populations at a lower level,          the predator is shipped on will adhere to the
including bifenthrin (Brigade) and fenpropathrin (Danitol). The          plants. Disperse them throughout the house
pyrethroids are most effective if the spider mite population has not     with heavier applications where TSSM colo-
yet reached high levels, and will be less effective if the spider mite   nies are found. Continue to monitor TSSM
population is high.                                                      populations. These predators are most ef-
Asparagus beetles                                                        fective on peppers and other plants that lack
    With the warmer weather now starting, asparagus beetle adults        sticky hairs on the leaves, although control
are beginning to show up in asparagus fields. Bob Moore (Helena          in tomatoes has been adequate prior to the
Co.) reports asparagus beetle eggs showing up in higher num-             onset of regular temperatures above 85ºF. o
bers on asparagus spears throughout the area, and adult feeding
                       See Pest Notes on page 5
Vol. 5 No. 7                                                                                                     Page 
   Vegetable Disease Update                                         ✔ Lettuce – Downy mildew – The disease is very
                                                              difficult to control once established in mature fields.
Andy Wyenandt, Ph.D., Specialist in Vegetable
                                                              Symptoms of lettuce downy mildew include irregular
Pathology and Wesley Kline, Ph.D., Cumber-                    yellowish-brown lesions on leaves. White, fuzzy sporu-
land County Agricultural Agent                                lation will develop on the underside of leaves under
                                                              ideal condition. Please scout on a regular basis. Use one
     ✔ Cole crops – Downy Mildew and Alternaria               of the following during periods of high moisture and
–Symptoms of Downy mildew include purple to yellow-           moderate temperatures.
ish-brown spots on upper leaf surfaces. A grayish-white             Alternate:
spore mass will develop and cover the underside of                 Maneb or OLF (M3) at 1.5-2.0 lb 75DF/A (7- to 10-
leaves under ideal temperatures (night temperatures of             day schedule) or OLF, or
46 to 61oF and day temperatures below 75oF. Downy                  Aliette (fosetyl AL, 33) at 3.0 lb 80WDG/A (14-day
mildew can kill young plants. Heavily infected leaves              With one of the following FRAC code 40 tank
may drop providing entry points for bacterial infec-               mixes:
tions (Black rot and Soft rot). Symptoms of Alternaria on          Revus (mandipropamid, 40) at 8.0fl. oz 2.08SC/A
infected leaves include small, expanding circular lesions          plus 1.5-2.0 lb maneb 75DF/A, or
with concentric rings that may have a ‘shot-hole’ ap-              Forum (dimethomorph, 40) at 6.0 fl oz 4.18SC/A
pearance as lesions age. Heavily infected seedlings may            plus 1.5-2.0 lb maneb 75DF/A
                                                                   or one of the following FRAC code 11 tank mixes:
result in damping-off. Control of Downy mildew and Al-
                                                                   Quadris (azoxystrobin, 11) at 6.0–15.5 fl oz 2.08SC/
ternaria begin with preventative fungicide applications.           A plus 1.5- 2.0 lb maneb 75DF/A, or
Use one of the following at the first sign of disease and          Tanos (famoxadone + cymoxanil, 11 + 27) at 8.0 oz
continue every 7 to 10 days (Please refer to the pesticide         50W/A plus 1.5- 2.0 lb maneb 75DF/A
table on page F21 of the 2009 NJ Commercial Vegetable              or
Production Recommendations to determine which fungi-               Previcur Flex (propamocarb HCL, 28) at 1.33 pt
cide is labeled for each specific crop.): Quadris (azoxys-         6F/A plus 1.5-2.0 lb maneb 75DF/A
trobin, 11) at 6.0 to 15.5 fl oz 2.08F/A, or chlorothalonil         ✔ Pepper – Phytophthora blight
(M5) at 1.5 pt 6F/A or OLF, or Cabrio (pyraclostrobin, 11)          For control of the crown rot phase of blight:
at 12.0 to 16.0 oz 20EG/A, or Endura (boscalid, 7) at 6.0           Apply 1.0 pt Ridomil Gold 4E/A or 1.0 qt Ultra
to 9.0 oz 70WG/A, or maneb (M3) at 1.5 to 2.0 lb 75DF/        Flourish 2E/A (mefenoxam, 4), or MetaStar (metalaxyl,
A or OLF, or Ridomil Gold Bravo (mefenoxam + chloro-          4) at 4.0 to 8.0 pt 2E/A.
thalonil, 4 + M5) at 1.5 lb 76.5WP/A (14-day schedule),             Apply broadcast prior to planting or in a 12- to
or Switch (cyprodinil, 9) at 11.0 to 14.0 oz 62.5WG/A         16-inch band over the row before or after transplanting.
(Alternaria only). For downy mildew only, apply Actigard      Make two additional post planting directed applications
(acibenzolar-S-methyl, P) at 1.0 oz 50WG/A (begin ap-         with 1 pint Ridomil Gold 4E or 1 qt Ultra Flourish 2E
plications 7-10 days after thinning and re-apply every 7      per acre to 6 to 10 inches of soil on either side of the
days for a total of 4 applications per season.), or Aliette   plants at 30-day intervals. Use formula in the “Calibra-
(fosetyl Al, 33) at 3.0 to 5.0 lb 80WDG/A (on 14-day          tion for Changing from Broadcast to Band Application”
schedule). For more information please see 2009 New           section of Calibrating Granular Application Equipment
Jersey Commercial Vegetable Production Recommenda-            to determine amount of Ridomil Gold needed per acre
tions Guide.                                                  when band applications are made.
     ✔ Lettuce – Bottom Rot/Drop – Growers should                   When using polyethylene mulch, apply Ridomil
take precautions to help control Bottom rot (Rhizocto-        Gold 4E at the above rates and timing by injection
nia) and Lettuce drop (Sclerotinia) which may cause po-       through the trickle irrigation system. Dilute Ridomil
tential problems. For Bottom rot, Endura 70W (boscalid,       Gold 4E prior to injecting to prevent damage to injector
FRAC code 7) at 8.0 to 11.0 oz/A, or iprodione (FRAC          pump.
code 2) at 1.5 to 2.0 lb/A or OLF should be applied one             ✔ Spinach - Downy Mildew and White Rust
week after transplanting or thinning and 10 and 20 days       – Scout on a regular basis, especially if spring plantings
later. For Lettuce drop, apply Endura (FRAC code 7) at        are near overwintered fields. Beginning 2 to 3 weeks
8.0 to 11.0 oz 70WG/A, Botran (dichloran, FRAC code           after emergence (and prior to symptom development),
14) at 2.0 to 5.5 lb 75WP/A, or iprodione (FRAC code 2)       apply the following on a 7 to 10 day schedule: Quadris
at 1.5 to 2.0 lb/A beginning one week after transplant-       (azoxystrobin, 11) at 6.0 to 15.5 fl oz 2.08F/A (use high
ing or thinning and again at 10 and 20 days later. For        rate for downy mildew), or Cabrio (pyraclostrobin, 11)
more information on control of Bottom rot and Lettuce         at 12.0 to 16.0 oz 20EG/A (use lower rate for white rust
drop and other important diseases of lettuce please see       only). Rotate to one of the following fungicides: Actigard
the 2009 New Jersey Commercial Vegetable Production           (acibenzolar-S-methyl, P) at 0.75 oz 50WG/A, or Aliette
Recommendations Guide.                                        (fosetyl Al, 33) at 3.0 lb 80WDG/A, or fixed copper
                                                                             See Disease Update on page 5
Page                                                                                                       Vol. 5 No. 7
                 Disease Update from page 4                            For subsequent applications, alternate:
(FRAC code M1) at labeled rates (Copper containing fun-                Captan (M3) at 4.0 lb 50WP/A, or Captevate (captan
gicides may cause some phytotoxicity), or Ridomil Gold            + fenhexamid, M3 + 17) at 3.5 to 5.25 lb 68WDG/A, or
Copper (mefenoxam + copper, 4 + M1) at 2.5 lb 65WP/               Switch (cyprodinil, 9) at 11.0 to 14.0 oz. 62.5WG/A or
A (on 14-day schedule). For more information please see           Pristine (pyraclostrobin + boscalid, 11 +7) at 18.5 to 23.0
the 2009 New Jersey Commercial Vegetable Production               oz 38 WG/A, or Thiram (M3) at 4.0 to 5.0 lb 65WSB/A
Recommendations Guide.                                                 ✔ Strawberry – Leather rot
     ✔ Strawberry – Anthracnose fruit rot -Strawberry             In New Plantings:
anthracnose can be extremely destructive during warm,                  Aliette (fosetyl-Al, 33) at 2.5 to 5.0 lb 80WDG/A.
wet weather causing significant fruit rot. Symptoms of            Begin 14 to 21 days after planting and continue on a 30
                                                                  to 60 day interval as long as favorable disease conditions
Anthracnose include blackish-brown circular spots on
                                                                  occur, or
maturing green fruit and soft, sunken (flat) circular le-
                                                                       Ridomil Gold (mefenoxam, 4) at 1.0 pt 4E/A. Make
sions on ripe fruit. On ripe fruit, lesions can expand rap-       one application at transplanting plus an additional ap-
idly and are often covered with a pinkish-orange spore            plication at fruit set or 30 days before harvest.
mass. Spores are spread from infected to healthy fruit            In Established Plantings:
with splashing water. Control of Anthracnose always                    Aliette (fosetyl-Al, 33) at 2.5 to 5.0 lb 80WDG/A, or
begins with a 7 to 10 day preventative spray program no                Ridomil Gold (mefenoxam, 4) at 1.0 pt 4E/A. Apply
later than 10% bloom and/or prior to disease develop-             in spring before first bloom and repeat once in the fall.
ment. For control apply the following combinations:                    ✔ Tomato – Bacterial spot and speck – Tomato
     #1) captan (M3) at 4.0 lb 50WP/A plus Pristine               transplants with suspected symptoms can be treated with
     (pyraclostrobin + boscalid, 11 + 7) at 18.5 to 23.0
     oz 38WG/A                                                    streptomycin (Agri-Mycin 17, Agri-Strep, 25) at 1 lb/100
     #2) captan 5(M3) at 4.0 lb 50WP/A plus Abound                gallons, or 1.25 teaspoon per gallon every 4 to 5 days
     (azoxystrobin, 11) at 6.0 to 15.5 fl. oz 2.08F/A or          prior to transplanting. Additionally, Kocide 3000 (cop-
     Cabrio (pyraclostrobin, 11) at 12.0 to 14.0 oz 20EG/A        per hydroxide, FRAC code M1), the updated formula-
     #3) Captevate (captan + fenhexamid, M3 + 17) at              tion from DuPont, has a greenhouse label for speck and
     3.5 to 5.25 lb 68WDG/A                                       spot control in the greenhouse. Apply ½ to 1.5 TBSP per
     For subsequent applications, alternate:
     captan (M3) at 4.0 lb 50WP/A plus Abound (azoxys-            1000 sq ft. every 5 to 10 days. Remember, phytoxicity
     trobin, 11) at 6.0 to 15.5 fl oz 2.08F/A, or                 is an important issue when applying copper in enclosed
     Cabrio (pyraclostrobin, 11) at 12.0 to 14.0 oz 20EG/A with   structures; see label for cautions, restrictions and li-
     captan (M3) at 4.0 lb 50WP/A, or                             abilities. After transplanting, apply Actigard at 0.33 oz
     Captevate (captan + fenhexamid, M3 + 17) at 3.5 to           50WG/A (see label for use), or fixed copper (M1) at 1 lb
     5.25 lb 68WDG/A                                              a.i./A plus a mancozeb (Dithane, Manzate, Penncozeb,
     To help manage fungicide resistance development,             M3) at 1.5 lb 75DF or OLF, or ManKocide (M1 + M3) at
do not make more than 2 consecutive applications of ei-           2.5 to 5.0 lb 61WP/A on a 7 day schedule. o
ther; Pristine (pyraclostrobin + boscalid, 11 + 7), Cabrio
(pyraclostrobin, 11) or Abound/Quadris (azoxystrobin,                               Pest Notes from page 3
11) before switching to another fungicide chemistry.              damage was evident in low amounts. Treat spears with
     ✔ Strawberry – Botrytis (Gray Mold) and Blossom              either carbaryl (Sevin), malathion, methomyl (Lannate),
blight – can cause serious losses in strawberry plantings         or permethrin (Pounce, Perm-Up) for management of the
in high tunnels and the field if not controlled properly.         adult beetles. After harvest is complete, and beetles are
Development is favored by moderate temperatures (59               still present, spinetoram (Radiant) and spinosad (SpinTor,
to 77 F) with prolonged periods of high relative humidity         Entrust) are labeled (post-harvest use only). Also, if pos-
and surface wetness. Control of Gray mold begins with             sible, daily harvesting of spears will reduce damage to a
preventative fungicide applications. Apply at 5 to 10             minimum. o
percent bloom and every 10 days until harvest. During
                                                                                Strawberry Notes from page 6
periods of excessive moisture, spray intervals of 5 to 7
days may be necessary. Rotate fungicide chemistries to            pollinators from flying. More pollination usually results
aid fungicide resistance management.                              in bigger fruit regardless. Each blossom should receive
     Application #1: captan (M3) at 4.0 lb 50WP/A plus            16 to 25 bee visits for complete pollination.
Topsin M (thiophanate-methyl, 1) at 1.0 lb 70WP/A or              IPM for Strawberries in the N.E. U.S. Guide
Switch (cyprodinil, 9) at 11.0 to 14.0 oz. 62.5WG/A                    IPM for Strawberries in the Northeastern U.S is avail-
     Application #2; Elevate (fenhexamid, 17 - See restric-       able from University of Massachusetts online bookstore
tions) at 1.1 to 1.5 lb 50WDG/A, or Pristine (pyraclos-           at: or by
trobin + boscalid, 11 + 7) at 18.5 to 23.0 oz 38 WG/A             calling 413-545-0895.
     Application #3: captan (M3) at 4.0 lb 50WP/A plus                 The guide covers nutrient and water management,
Topsin M (thiophanate-methyl, 1) at 1.0 lb 70WP or
                                                                  as well as identifying and controlling pests, diseases and
Switch (cyprodinil, 9) at 11.0 to 14.0 oz. 62.5WG/A
                                                                  weeds. Includes 77 color photos. $7.00. o
Vol. 5 No. 7                                                                                                         Page 5
            Strawberry Notes                                        1) Some cultivars just do that. There can be bumps,
                                                               folds, crinkles, and hollow berries that split open at the
                                                               tip. This happens more frequently with cultivars that are
Sowbugs in Strawberries                                        known for a huge size. Cabot, Camarosa, and Albion
Kathy Demchak, Penn State Horticulture                         tend to do this, and almost always, it’s just with the pri-
Reprinted from The Vegetable and Small Fruit Gazette,          mary berries. Mesabi also may have misshapen berries,
The Pennsylvania State University, May 2009, Volume            but to a lesser extent, and low boron could also play a
13, No. 5                                                      role (see below). Once you are producing secondary
     Q. A local grower mentioned he was having trouble         and tertiary berries, this becomes less of a problem, pos-
with sowbugs eating holes in his strawberries last year.       sibly because more pollen is available – source of pollen
However, the literature says that sowbugs eat dead and         and timing of pollen release also may play a role.
decaying organic matter, and that they typically aren’t             2) Environmental conditions during bloom that
a problem for crops. Have you ever heard of this hap-          would have affected pollination. This can be tempera-
pening anywhere else? Are there any materials that can         tures below freezing, which can damage flower parts.
be used to help with this problem? (Tim Elkner, PSU            A hot dry spell can cause the stigmas (located on the
Cooperative Extension, Lancaster County, PA).                  yellow “cone” in the center of the flower) to dry out,
     A. Yes, and yes. We had major problems with sow-          and therefore, the pollen doesn’t stick. In the case of
bugs eating holes in strawberry fruit in our high tunnels.     cold temperatures, the berry may appear folded, or the
I thought the problems we were having were isolated in-        tip may be affected. With hot dry temperatures, pollen
cidents, but since then, I’ve heard from a few strawberry      may stick only where the stigmas touch the anthers. The
growers with sowbug problems, and the problem has oc-          anthers are located in a circle around the stigmas. In ex-
curred in the field as well as in high tunnels. Maybe the      treme cases, the berry may end up shaped like a doughnut.
problem wasn’t as isolated as I thought. In every case              3) Damage to the flower from a mixture of spray
where sowbugs have been a problem, there has been              materials applied during bloom. I’ve only suspected this
organic matter involved, either as a mulch, a compost,         in cases where more than 3 or 4 materials were applied
an unharvested root crop, or wood for permanent raised         in a tank mixture at one time. There is some indication
beds that started to decompose, as in our tunnels. In          in the literature that when high calcium concentrations
these situations, the sowbug population starts build-          are applied to flowers (much higher than those found
ing on an abundant organic (organic meaning carbon-            when labeled directions for nutritional supplements are
containing, in this case) source of food, but once the         followed), pollen viability is affected. So, you might
population becomes high and the original food source           want to measure. More often isn’t better.
decomposes further, the sowbugs will eat whatever they              4) Low boron or zinc. Both are involved in pollen
can find that is soft enough. Strawberries certainly fit       tube growth, so incomplete pollination takes place. Bad
the bill. One of the growers had tried a product called        pollination = no seeds, and when seeds don’t develop,
Sluggo Plus (other trade names exist) that is labeled for      the fruit doesn’t enlarge. The seeds produce the growth
control of both snails and sowbugs (and some other             regulator that causes the berries to expand. This is one
soil-dwelling pests), and apparently it worked quite well.     reason why we like to see growers use tissue analysis.
Sluggo Plus contains iron phosphate for slug control           Low boron is more likely to be a problem on sandy soils.
(same as in the product Sluggo) and spinosad, which            Boron levels in the soil should be above 1.5 pounds per
affects the sowbugs and other insect pests. One caution        acre, or 0.75 ppm, and tissue levels should be between
is that there is a 3-day PHI for Sluggo Plus, as opposed to    30 and 70 ppm.
Sluggo which can be used up to the day of harvest. So,              5) Seed destruction (seeds may only be hollowed
if you’re seeing sowbugs, you’ll want to get this product      out) from an insect, mostly likely tarnished plant bugs.
on before harvest begins.                                      Adult tarnished plant bugs fly away fast, so it’s possible
Causes of Misshapen Strawberries                               to miss the problem until you see the green nymphs
                                                               crawling around. Usually tarnished plant bugs are a
Kathy Demchak, Penn State Horticulture
                                                               bigger problem where you have weeds, on which they
Reprinted from The Vegetable and Small Fruit Gazette, The
                                                               multiply. Long-necked seed bugs are occasionally a
Pennsylvania State University, May 2009, Volume 13, No. 5
                                                               problem, and as the name implies, look like they have
     Every year, I’ll get several calls about misshapen ber-
                                                               a long neck. They are dark brown, slender, and have
ries. There are a lot of possible causes, so if you notice
                                                               tiny little heads. They move really fast and hide under
strange strawberry shapes, check over this list, and see if
                                                               leaves. Both tarnished plant bugs and long-necked seeds
some of these items apply to your situation – that could
                                                               bugs cause a “button-berry” shape most commonly, but
help with sorting out the cause of the problem. In cases
                                                               other shapes are possible.
where a weather event or a spray is suspect (see below),
                                                                    6) Poor pollination from a lack of pollinators, or
the berry shape improves in a few days, indicating that a
                                                               damp rainy weather during bloom, which discourages
short-lived event was responsible.                                             See Strawberries on page 5
Page 6                                                                                                      Vol. 5 No. 7
      EQIP Organic Farming                                     The sign-up period begins Monday, May 11 and goes
                                                               through Friday, May 29. Six core conservation practices
           Assistance                                          (conservation crop rotation, cover cropping, integrated
                                                               pest management, nutrient management, rotational graz-
                                                               ing, and forage harvest management) are being made
     USDA announced a special three-week sign-up for           available to transitioning organic farmers on a nation-
farmers in the process of converting to organic farming        wide basis. Each state may then also add a variety of
to receive technical and financial assistance through          ‘facilitating’ conservation practices specific to the type of
the Environmental Quality Incentives Program (EQIP),           agriculture in their region.
a move applauded by the National Sustainable Agricul-               The new initiative addresses the special ‘organic
ture Coalition and its grassroots member organizations         conversion assistance’ component of EQIP in particular.
across the country.                                            Funding under the organic conversion section of the
     The organic conversion assistance was provided for        farm bill is capped at not more than $20,000 per farm
by the 2008 Farm Bill but the plan went awry when the          per year, and not more than $80,000 per farm in any
Bush Administration issued rules for the EQIP program          6-year period. Organic farmers may opt to compete
just before leaving office which baffled state and local       in this special pool, with the tighter payment caps, or
offices of USDA’s Natural Resources Conservation Service       may opt instead to compete in the regular EQIP pool
(NRCS). As a result, in a majority of states organic farmers   for which the 6-year cap is $300,000. However, under
and transitioning farmers were simply not being served, in     the terms of the new initiative announced today, farmers
contradiction of Congress’ intent in the farm bill.            will receive higher payments, relative to conventional
     Today’s announcement sets-aside $50 million out           EQIP rates, for five of the six national core practices for
of the $1 billion EQIP program for a special three-week        organic conversion option. The higher payment rates
sign-up for farms converting to organic production,            reflect the higher management costs associated with
farms expanding their organic production, or exist-            the mandatory three-year organic transition period and
ing organic farms who desire conservation support to
                                                               the higher ongoing management costs associated with
reach even higher levels of environmental performance.
                                                               organic farming. o

                                   Weekly Weather Summary
Keith Arnesen, Ph.D., Agricultural Meteorologist

    T   emperatures averaged much above normal, averaging 61 degrees north, 61 degrees central and 63 degrees
        south. Extremes were 95 degrees at Toms River on April 28th, and 38 degrees at Toms River on May 1st.
Weekly rainfall averaged 0.59 inches north, 1.08 inches central, and 0.65 inches south. The heaviest 24 hour total re-
ported was 0.83 inches at New Brunswick and Freehold on the 3rd to 4th. Estimated soil moisture, in percent of field
capacity, this past week averaged 85 percent north, 79 percent central and 70 percent south. Four inch soil tempera-
tures averaged 62 degrees north, 62 degrees central and 64 degrees south.
                              Weather Summary for the Week Ending 8 am Monday 5/ 4/ 9
                                  RAINFALL                TEMPERATURE                       GDD BASE50 MON
    WEATHER STATIONS              WEEK TOTAL DEP          MX       MN      AVG     DEP      TOT      DEP      %FC
    BELVIDERE BRIDGE              .59     4.34    -3.92 90         45      61.     5        162      105      85
    CANOE BROOK                   .51     5.94    -3.15 90         43      62.     7        190      145      89
    CHARLOTTEBURG                 .24     5.48    -3.47 90         44      61.     8        159      144      78
    FLEMINGTON                    1.14    5.81    -2.88 93         41      62.     6        207      156      99
    NEWTON                        .45     3.91    -4.06 90         47      61.     7        166      140      84
    FREEHOLD                      1.07    8.04    -.57    87       40      60.     3        199      122      98
    LONG BRANCH                   1.02    8.22    -.69    90       41      59.     3        148      87       100
    NEW BRUNSWICK                 1.48    7.12    -1.19 90         40      61.     3        190      94       100
    TOMS RIVER                    .78     8.65    -.05    95       38      62.     6        212      145      88
    TRENTON                       1.07    5.57    -2.24 90         41      63.     5        237      122      98
    CAPE MAY COURT HOUSE .25              7.65    .07     91       48      62.     4        228      130      65
    DOWNSTOWN                     .55     6.81    -1.00 92         43      63.     4        219      96       79
    GLASSBORO                     1.03    9.18    .94     89       46      62.     4        230      115      95
    HAMMONTON                     .53     6.03    -1.98 92         40      63.     5        257      147      74
    POMONA                        .49     8.50    .87     92       41      63.     6        264      183      74
    SEABROOK                      1.05    7.20    .20     89       47      62.     3        247      121      95
    SOUTH HARRISON                missing
    WES KLINE -- GDD BASE 40 PINEY HOLLOW LAST WEEK 132 (Ending 4/27/09) THIS WEEK 165 (Ending 5/4/09)
Vol. 5 No. 7                                                                                                       Page 7
                                                                          New Brunswick, N.J. 08901
                                                                          ASB II, 57 US Hwy. 1
                                                                          and Biological Sciences
                                                                          Rutgers School of Environmental
                                                                          Plant & Pest Advisory
   PERMIT #576

                                                                Pesticide User Responsibility: Use pes-
           PLANT & PEST ADVISORY                                ticides safely and follow instructions on
    VEGETABLE CROPS EDITION CONTRIBUTORS                        labels. The pesticide user is reponsible for
                                                                proper use, storage and disposal, residues
Rutgers NJAES Cooperative Extension Specialists
Gerald M. Ghidiu, Ph.D., Vegetable Entomology                   on crops, and damage caused by drift. For
George Hamilton, Ph.D., Pest Management                         specific labels, special local-needs label
Joseph R. Heckman, Ph.D., Soil Fertility                        24(c) registration, or section 18 exemption,
Bradley A. Majek, Ph.D., Weed Science                           contact RCE in your County.
Andy Wyenandt, Ph.D., Vegetable Pathology                       Use of Trade Names: No discrimination
Rutgers NJAES-CE County Agricultural Agents                     or endorsement is intended in the use of
Atlantic, Richard W. VanVranken (609-625-0056)                  trade names in this publication. In some
Burlington, Raymond J. Samulis (609-265-5050)                   instances a compound may be sold under
Cape May, Jenny Carleo (609-465-5115)                           different trade names and may vary as to
Cumberland, Wesley Kline, Ph.D. (856-451-2800)                  label clearances.
Gloucester, Michelle Infante-Casella (856-307-6450)             Reproduction of Articles: RCE invites
Hunterdon, Winfred P. Cowgill, Jr. (908-788-1338)
                                                                reproduction of individual articles, source
Middlesex, William T. Hlubik (732-398-5260)
Monmouth, Bill Sciarappa, Ph.D. (732-431-7260)                  cited with complete article name, author
Morris, Peter J. Nitzsche (973-285-8300)                        name, followed by Rutgers Cooperative Ex-
Passaic, Elaine F. Barbour, Agric. Assistant (973-305-5740)     tension, Plant & Pest Advisory Newsletter.
Salem (856-769-0090)
Warren, William H. Tietjen (908-475-6505)                         The Vegetable Crops On-Line Resource
Vegetable IPM Program (732-932-9802)                          Center website is a dedicated source for infor-
Joseph Ingerson-Mahar, Vegetable IPM Coordinator              mation on production, insect, weed and disease
Kristian E. Holmstrom, Research Project Coordinator II        management, food safety, marketing and more:
Newsletter Production                               
Jack Rabin, Associate Director for Farm Services, NJAES
Cindy Rovins, Agricultural Communications Editor              For back issues of the Plant & Pest Advisory:

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