EFFECTS OF DIFFERENT SEED TREATMENTS AND COATINGS ON THE

Document Sample
EFFECTS OF DIFFERENT SEED TREATMENTS AND COATINGS ON THE Powered By Docstoc
					Journal of Turfgrass Science Vol. 73 (1997)

EFFECTS OF DIFFERENT SEED TREATMENTS AND COATINGS ON
THE GERMINATION AND ESTABLISHMENT OF FOUR GRASS
SPECIES
By A.J. NEWELL
The Sports Turf Research Institute, Bingley, West Yorkshire, BD16 1AU

SUMMARY
The effects of five seed treatments on the establishment of four species of grass (Agrostis tenuis
Sibth., Festuca rubra L., Poa pratensis L. and Lolium perenne L.) following sowing on
1 November 1994 were investigated. Highly significant differences were found among grass
species in the rate and success of establishment. L. perenne established most successfully overall
and at a faster rate than F. rubra which in turn was faster than P. pratensis. The plots sown with
A. tenuis showed rapid initial establishment but failed to survive the prevailing winter conditions.
Two of the seed treatments, those which contained metalaxyl, increased rates of establishment
overall and had a marked effect on the establishment of F. rubra. These treatments were found
to have significantly higher ground cover than the controls during and at the end of the study.
Metalaxyl-treated plots of F. rubra were comparable in terms of ground cover with L. perenne
at the end of the study. As no disease was noted during this investigation it is suggested that the
promotion of grass establishment by metalaxyl or metalaxyl in combination with other chemicals
resulted from these treatments stimulating other plant responses. The other chemical treatments
did not statistically affect establishment of the different grass species. It is also important to
note that no negative effects on establishment or sward appearance were recorded for any of the
chemical and or coating treatments.

INTRODUCTION                                            clearance for control of plant diseases also
There are in the region of fifty different              affected seedling and young plant vigour.
products on the market which can be, or are
designed to be, used as seed treatments. The            It is possible to speculate that the effectiveness
majority of these have clearance for the control        of different chemicals used as seed treatments
of fungal diseases (Anon. 1997). Some of                would be dependent on the method of
these products can be used to treat grass seed.         application to the seed, as well as the specific
Anon. (1995) listed eight such products: five           characteristics of the chemicals involved. In
fungicides, one insecticide, one bird and rodent        this regard, an application technique which
repellent, and one aid to germination and seed-         tightly bound the chosen chemicals to the seed,
ling survival. For the seed treatments which            thus reducing loss of active chemical from the
are currently in use or which have been the             seed during handling and leaching away from
subject of past testing, fairly variable results        the seed following sowing, may be of some
have been reported regarding their effective-           advantage. In the study reported below, some
ness for use on grass seed. Smith et al. (1989)         of the seed treatments were applied as a
in a review listed various chemical seed                polymer coating which was designed to reduce
treatments which were shown to have some                losses due to handling and maximise the
effectiveness against damping-off in turf-              contact and longevity of that contact with the
grasses. These workers also described reports           seed following sowing. This study also tested
which found fungicidal grass seed treatments            the effects of other, more traditionally-applied
to be marginally beneficial, of no benefit,             chemicals on the establishment of four differ-
erratic and of considerable advantage. They             ent grass species. This research programme
also reported that some products which had              was jointly funded by Force Limagrain
                                                   67
GRASS SPECIES AND SEED TREATMENTS

Limited and Agrichem (International)                   1995 measurements were made weekly to 13
Limited.                                               March 1995, with a second measurement being
                                                       made in the final week on 16 March. The
MATERIALS AND METHODS                                  reflectance ratio itself is strongly and posi-
A turfgrass germination and establishment              tively associated with live ground cover and
trial was sown by hand into 1 m x 1 m plots in         as such makes a rapid and repeatable measure
the STRI trial grounds (NGR SE 095 391,                of relative grass establishment (Haggar &
altitude 200 m) on 1 November 1994. This               Isaac, 1985). In addition, germination and
trial was a factorial design with four complete        subsequent establishment was scored on a 0 to
replications. In this, four grass species were         9 scale. In this scale 0=no shoots visible, 1=a
tested: A. tenuis (Egmont), L. perenne (Flair),        few shoot tips visible on close inspection,
P. pratensis (Fortuna) and F. rubra (Bingo) in         2=shoot tips visible in the majority of the plot
combination with five chemical seed                    on close inspection, 3=shoots visible when
treatments. These treatments were; Agrichem            standing and looking down on the plot, 4=first
Flowable Thiram and H116 (supplied by                  leaf starting to emerge, 5=first leaf fully
Agrichem (International) Limited), and three           emerged, 6=second leaf starting to emerge,
coated seed treatments, Co1 (Agrichem Flow-            7=second leaf fully emerged, 8=third leaf
able Thiram, Maxicrop, Curb and Metalaxyl),            starting to emerge and 9=third leaf fully
Co2 (Maxicrop, Curb, Thiabendazole, Thiram             emerged. Leaves were classified as starting
and Metalaxyl) and Co3 (Agrichem Flowable              to emerge only when they were clearly visible
Thiram, Maxicrop and Curb). Coatings were              and in the case of the broader species starting
applied by Seppic, France, using their Sepiret         to unroll or unfold. Scores were made twice
polymer. Untreated seed for each species and           weekly up to 20 December 1994 with a final
seed treated with Sepiret polymer alone were           score being made on 16 January 1995. After
also used as controls. After sowing, the trial         the first week, when changes were occurring
was covered using a Tildenet ground                    very rapidly, weekly scores were averaged to
protection cover, this was rolled back to make         increase the precision of the subsequent
measurements each week. This cover was                 analyses. After December 1994 the scores
completely removed after assessments were              became difficult to make as all plots showed
made on 22 December 1994.                              signs of winter/water logging damage. How-
                                                       ever, the A. tenuis treatments in particular were
The reflected ratio of far red to red light            very severely affected and towards the end of
(reflectance ratio) was measured twice weekly          the study there was little live ground cover left
from 14 November 1994 to 30 January 1995,              in any of the A. tenuis plots. A brief summary
excluding the period between 20 December               of weather data and times when damage was
1994 and 6 January 1995. After 30 January              noted in plots is set out in Table 1.

                                             TABLE 1
               Weather data recorded at the STRI, Bingley between 1 November 1994
                and 16 March 1995. The date when winter/water logging damage to
                                  plots were noted are also given.

        Total rainfall               Snow cover                        Frost              Plant damage

Nov 1994          115.8 mm           4 Jan 1995 (10 mm)                2 Nov 1994         9 Dec 1994
Dec 1994          151.85 mm          25 Jan 1995 (250 mm)              11 Jan 1995        9 Jan 1995
Jan 1995          150.1 mm           27 Jan 1995 (50 mm)               2 Feb 1995         6 Feb 1995
Feb 1995          122.65 mm          2 Mar 1995 (40 mm)                24 Feb 1995
16 Mar 1995       38.65 mm           3 Mar 1995 (20 mm)                25 Feb 1995
                                     8 Mar 1995 (10 mm)

                                                  68
                                                        GRASS SPECIES AND SEED TREATMENTS

All data were examined using analysis of                     develop past the first leaf stage. By the end of
variance. Protected least significant differ-                the trial there was little live ground cover left
ences were calculated for treatment means                    in any of the A. tenuis plots (see later). The F.
where the probability that differences due to                rubra and P. pratensis in particular took longer
chance alone were less than P=0.05.                          before they showed signs of emergence but
                                                             when they did emerge both grasses continued
RESULTS                                                      to develop throughout the study. The overall
Grass species                                                reflectance ratio measurements for the four
Establishment scores for the different grass                 grass species are presented in Table 3. These
species are presented in Table 2. These show                 data demonstrate similar findings to those
that there were marked differences in estab-                 reported above for the establishment scores.
lishment among grass species. However, these                 In that ground cover for the L. perenne
scores did not demonstrate differences                       increased more rapidly and reached larger
between chemical treatments overall or effects               overall values than the other grass types in trial.
of seed treatments within the different grass                Also that the A. tenuis failed to produce
species (data not shown). With regard to the                 significant ground cover after the early stages
differences between species, L. perenne was                  of this study.
found to show signs of emergence first and
reached a higher level of development faster                 Seed treatments
than the other grass species. The A. tenuis                  Reflectance ratio measurements for the differ-
emerged nearly as quickly but then failed to                 ent seed treatments are presented in Table 4.

                                                  TABLE 2
    Relative establishment scores made between November 1994 and January 1995 for the four grass
 species in the 1 November 1994 sown grass species and seed treatment trial. Grass establishment was
scored on a 0 to 9 scale (0=no shoots visible, 1=a few shoot tips visible on close inspection, 2=shoot tips
visible in the majority of the plot on close inspection, 3=shoots visible when standing and looking down
 on the plot, 4=first leaf starting to emerge, 5=first leaf fully emerged, 6=second leaf starting to emerge,
      7=second leaf fully emerged, 8=third leaf starting to emerge and 9=third leaf fully emerged).

Grass type     Week 46a Week 46b Week 47 Week 48 Week 49 Week 50 Week 51 Week 3
               November 1994                                           January 1995

A. tenuis         0.9          2.7         2.9           2.9           3.0        3.0           3.5    3.9
P. pratensis      0.0          0.8         1.9           2.9           3.3        3.7           4.6    5.8
F. rubra          0.0          1.6         2.8           3.0           4.0        4.6           5.8    7.0
L. perenne        1.9          3.0         3.8           5.0           6.0        6.0           6.9    8.1
LSD               NA           0.2         0.2           0.1           0.1        0.1           0.2    0.3
NA=not analysed

                                               TABLE 3
 Reflectance ratio (ground cover) measurements made between 16 November 1994 and 16 March 1995
     for the four grass species in the 1 November 1994 sown grass species and seed treatment trial.

Grass type                November          December                 January            February       March

A. tenuis                     8.5                13.5                  6.8                6.9             5.5
P. pratensis                  4.9                19.8                 22.2               18.9            15.9
F. rubra                     12.1                31.3                 32.2               27.8            30.5
L. perenne                   23.2                44.6                 45.5               41.5            48.1
LSD                           2.1                 3.2                  2.9                2.3             2.8

                                                        69
GRASS SPECIES AND SEED TREATMENTS

                                                 TABLE 4
 Reflectance ratio (ground cover) measurements made between 16 November 1994 and 16 March 1995
 for the seven different seed treatments in the 1 November 1994 sown grass species and seed treatment
                                                   trial.

Seed treatment        November          December               January          February           March
Control                  10.8              24.3                  23.8              21.2              21.1
Thiram                   12.3              25.9                  25.6              22.9              24.0
H116                     13.7              28.0                  25.7              21.8              23.7
Co Control               10.9              24.2                  23.0              21.1              21.7
Co1                      12.8              31.1                  31.6              28.3              30.1
Co2                      12.5              30.6                  31.4              28.9              30.8
Co3                      12.3              26.9                  25.8              22.5              22.7
LSD                       NS                4.2                    3.9              3.0               3.7



These show that there was a consistent,                  December onwards. At this level of the
prolonged and positive effect for two of the             analysis there were few if any other consistent
seed treatments from December 1994 to the                statistical differences among the different seed
end of the investigation on 16 March 1995.               treatments within each grass species.
The treatments Co1 and Co2, which both
contained Metalaxyl, Maxicrop and Curb,                  DISCUSSION
were found to markedly increase ground cover.            Dealing with differences among grass species
In March 1995 reflectance ratio values were              first, this work has demonstrated two very
some 35% to 40% higher overall in plots sown             important points; firstly, A. tenuis showed
with these two treatments in comparison with             signs of establishment fairly rapidly but did
plots sown with the control (untreated seed)             not continue to develop. This was most likely
or the coating control (Polymer coated seed).            a reflection of the inability of this grass to cope
However, it would appear that Metalaxyl on               with winter conditions in a juvenile state,
its own or in combination with other chemicals           which in turn was a result of the late sowing.
stimulated establishment as the seed coating             Secondly, L. perenne, F. rubra and most
which included the above chemicals with the              surprisingly P. pratensis all continued to
exception of Metalaxyl (Co3) did not differ              develop throughout the winter period. It is a
significantly from the two controls. It is also          common suggestion that P. pratensis should
important to note that no disease was evident            not be sown late in this country as it needs
on any of the plots during the investigation             fairly warm soil temperatures for successful
and as a consequence it is assumed that                  establishment (Newell 1994). This work
differences in ground cover resulted from                would conflict with this statement. Apart from
factors other than disease.                              the above, the establishment scores support
                                                         other long held and common views that L.
Full details of the reflectance ratio measure-           perenne establishes faster than F. rubra which
ments for each individual grass species and              in turn establishes faster than P. pratensis.
treatment are presented in Table 5. These data
demonstrate what appears to be an additional             The establishment score used was able to
positive effect on the establishment of F. rubra.        discriminate differences well among species
For this grass type the swards developing from           but was unable to discriminate among seed
seed treated with the coatings ‘Co1’ and ‘Co2’           treatments. In contrast, the reflectance ratio
had comparable estimated ground covers to                measurements demonstrated differences both
that found generally for L. perenne plots from           among species and seed treatments. This
                                                    70
                                                    GRASS SPECIES AND SEED TREATMENTS

                                                TABLE 5
 Reflectance ratio (ground cover) measurements made between 16 November 1994 and 16 March 1995
   for the four grass species and seven different seed treatments in the 1 November 1994 sown grass
                                     species and seed treatment trial.

Seed treatment
and grass species      November          December               January        February          March
A. tenuis
Control                   7.9              10.8                   5.6             5.2             3.8
Thiram                    9.4              12.0                   6.0             5.4             3.7
H116                     10.9              15.1                   6.9             6.2             5.7
Co Control                7.8              14.0                   7.3             6.6             5.7
Co1                      10.5              16.3                   8.5             8.5             6.3
Co2                       6.0              15.4                   8.2            10.0             8.7
Co3                       7.2              10.8                   5.1             6.3             4.7
P. pratensis
Control                   4.6              20.4                  23.2            19.3            17.1
Thiram                    3.3              15.6                  19.3            18.0            14.3
H116                      5.9              19.7                  21.8            17.7            14.3
Co Control                3.1              16.8                  18.6            17.8            14.5
Co1                       6.4              24.1                  26.7            21.3            19.3
Co2                       4.9              20.8                  23.5            20.6            17.1
Co3                       5.7              21.1                  22.4            17.9            14.7
F. rubra
Control                   8.2              24.7                  24.6            21.6            23.4
Thiram                   13.2              30.6                  30.7            25.5            28.4
H116                     13.2              32.8                  29.7            24.2            27.5
Co Control               10.4              23.3                  22.4            19.6            19.8
Co1                      12.5              38.8                  44.0            40.0            44.6
Co2                      16.2              41.0                  45.6            40.4            46.3
Co3                      11.2              28.0                  28.7            23.4            23.3
L. perenne
Control                  22.5              41.3                  41.8            38.6            44.1
Thiram                   23.4              45.5                  46.3            42.6            49.5
H116                     24.8              44.5                  44.3            38.9            47.2
Co Control               22.2              42.6                  43.8            40.4            46.8
Co1                      21.6              45.3                  47.1            43.3            50.2
Co2                      23.0              45.1                  48.1            44.6            51.2
Co3                      25.1              47.8                  47.2            42.4            48.1
LSD                       NS                NS                    7.8             6.1             7.4


difference was probably due to the establish-            Considering the seed treatments, this study
ment score assessing development which was               demonstrated that the treatments which
dependent on the stage of development of                 contained metalaxyl (Co1 and Co2) promoted
individual plants within the sward, whereas              ground cover in general and in particular
the reflectance ratio measured the live area             dramatically so for F. rubra. It is very
covered by the sward as a whole. In this                 important to note that this increase in ground
regard, it is feasible that plants which survived        cover was independent of any disease effects
the winter period developed and indeed                   as no disease was recorded on any of the plots
became larger as individuals while the ground            during this investigation. It was reported
cover of the sward as a whole did not change             earlier that some products intended for use in
or even decreased due to winter kill.                    the control of seedling diseases have also been
                                                    71
GRASS SPECIES AND SEED TREATMENTS

found to promote seedling and young plant                 which promoted establishment were applied
vigour (Smith et al. 1989). The effects of                in a polymer coating. It would be of interest
metalaxyl on its own or in combination with               to investigate the effectiveness of metalaxyl
other chemicals appear to fall in to this                 and other chemicals both applied in a polymer
category. Please note that three of the other             coating and by more traditional methods.
chemicals (Thiram, Maxicrop and Curb,
treatment Co3) when tested without metalaxyl              ACKNOWLEDGEMENTS
did not significantly effect ground cover. Also,          The author would like to thank Force
establishment was promoted by both treat-                 Limagrain Ltd. and Agrichem (International)
ments Co1 and Co2 but only one of these                   Ltd. for funding and allowing this work to be
contained thiabendazole. Baldwin & Margot                 published. I would also like to thank Miss
(1990) have also reported positive effects of             A.C. Jones for help with data collection and
metalaxyl on sward establishment. However,                the grounds staff at the STRI for land
in this case the promotion of establishment               preparation and maintaining the trial.
(increased shoot density) was associated with
fairly severe levels of disease in other chemical         REFERENCES
and control plots. That metalaxyl can promote             Anon. (1995). A Guide to Seed Treatments in
establishment both with and without disease                  the UK. Third edition (Ed. D. Soper).
being present raises an interesting question;                BCPC Publications, Surrey, Great Britain,
should a product be sold for one purpose but                 pp. 46.
purchased for another?                                    Anon. (1997). The UK Pesticide Guide (Ed.
                                                             R. Whitehead). CAB International and
In addition to the above, it is very important               BCPC, University Press, Cambridge, Great
to record that no negative effects were                      Britain, 645 pp.
recorded for any of the chemical treatments               Baldwin, N.A. & Margot, P. (1990). Seedling
tested, and it is possible that other beneficial             diseases of turfgrasses caused by Fusarium
effects would have been found if seedling                    culmorum and Cladochytrium caespitis
diseases had occurred. Also, it is possible that             and their control by fungicide seed
additional seed treatment effects for P.                     treatments. In: Proceedings of the 1990
pratensis and A. tenuis were masked by the                   Brighton Crop Protection Conference –
slow development of P. pratensis and the                     Pests and Diseases 4, 29-36.
failure of A. tenuis to survive in the prevailing         Haggar, R.J. & Isaac, S.P. (1985). The use of
winter conditions.                                           a reflectance ratio meter to monitor grass
                                                             establishment and herbicide damage.
Finally, it is of value to note that the longevity           Grass and Forage Science 40, 331-334.
of the chemical effects, where differences were           Newell, A.J. (1994). Grasses for winter
found, were fairly long lived. In this regard,               pitches. In: Winter Games Pitches (Ed.
differences first noted in December were still               R.D.C. Evans), STRI, England, pp. 96-
apparent in the following March. However, it                 109.
is not feasible to comment if this was just               Smith, J.D., Jackson, N. & Woolhouse, A.R.
related to the chemicals themselves or if it was             (1989). Fungal Diseases of Amenity
effected by their method of application to the               Turfgrasses. E.&F.N. Spon, London and
seed. In this study the chemical treatments                  New York, pp. 49-52.




                                                     72

				
DOCUMENT INFO
Shared By:
Categories:
Stats:
views:15
posted:1/27/2011
language:English
pages:6