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Everglades Station Uimeo Report 60-18 1 May 1960
RESUME OF RECENT HERBICIDE RESEARCH ON ORGANIC SO"IL 1' o 90 .-
J. R. Orsenigo
This brief report summarizes information from recent herbicide trials on
organic soil. Some of the data have been presented before the regional and
national weed conferences while other data will be published in ex-enso in the
future. Specific details pertaining to these experiments will be provided on
request. Treatments discussed herein are not implied as recormendat-ions for
any herbicide for any usage. Herbicidal chemicals should not be utilized in
any manner contrary to label recommendations or current limitations of the USDA
and FDA.
Celery Herbicides
Post transplanting (but prior to weed emergence)
Combinations of Vegadex and Randox: Vegadex and Randox
applied alone or in combination with each other had no significant influence
upon number or length of petioles or weight of fresh-trimmed plants or yield of
52-70H. Randox and its combinations provided grass control superior to Vegadex.
Randox is not currently cleared for use on celery. Yield data are given in
Table 1.
Table 1. Celery yield in crates per acre for Vegadex, Randox
and combination treatments. (Rates are quarts of product per
sprayed acre)
Herbicidal treatment Crates/acre
Cultivated check 733
Randox, 4 qts. 738
5 qts. 714
6 qts. 693
Vegadex, 4 qts. 710
5 qts. 711
6 qts. 777
Randox 2 qts. + Vegadex 2 qts. 695
Randox 2 qts. + Vegadex 3 qts. 745
Randox 3 qts. + Vegadex 2 qts. 730
Randox 3 qts. + Vegadex 3 qts. 750
Repeat applications of VegadeX and Randox: Vegadex, Randox and
hand-weeded plots were installed immediately following transplanting. The same
treatments were repeated three and four weeks later and reciprocal applications
were made also. Weed control was best when treatments were repeated at tLree
weeks after setting and Randox was a better herbicide than Vegadex. Herbic.ide
tolerance, number and length of petioles, weight of fresh-trimmed plants, ad
yield of 52-70 celery were not significantly affected by the treatments. Randox
is not currently cleared for use on celery but Vegadex has approval for a second
application to celery. Yield data are given in Table 2.
Table 2. Weed control and celery yield for repeat applications
of Vegadex and Randox herbicides. Average values for treatments
repeated at 3 and 4 weeks after setting.
Herbicidal
Original
treatment
Repeat
Weed control two
weeks after repeat
Yield
Crates/acre
Randox, 5 qts.
Handweeded
Randox, 5 qts.
Randoxc, 5 qts.
Vegadex, 5 qts.
Handweeded
Vegadex, 5 qts.
Vegadex, 5 qts.
None
Handweeded
None
Randox, 5 qts.
Randox, 5 qts.
Vegadex, 5 qts.
None
Vegadex, 5 qts.
Vegadex, 5 qts.
Randox, 5 qts.
Karsil + Vegadex
Handweeded
Post emergence to celery and weeds
in seedbeds
Karsil (NIA 4562) has effectively controlled the following seed-
ling weeds in celery seedbeds: bedstraw, carelessweed, Chenopodita, crabgrass,
cudweed, dog-fennel, Eclipta, Galinsoga, goosegrass, pellitoryweed, purslane,
stickerweed, ragweed, Rorippa, and others. Relatively few annual weed seed-
lings are resistant; however, weed tolerance increases with age. celery seed-
lings with fewer than 3 true leaves when sprayed are stunted severely and there
is some stand reduction. Larger celery seedlings are stunted temporarily and
at time of transplanting are equal to check plants in growth and weight. After
field harvest plants from treated beds have not differed significantly from
checks in number or length of petioles, or crates per acre yield. Karsil is an
experimental herbicide currently not available commercially. Yield data from
commercial trials are given in Table 3.
Table 3. Average yield of 52-70 celery following post emergence
application of Karsil to seedbeds at five (5) locations. Rates
of application are pounds active per acre to the seedbeds.
Seedbed herbicidal treatment
Karsil, 1 lb.
2 Ib.
3 Ib.
Karsil, 1 lb. + Vetaiex 2 Ibs.
Check, handweeded
Yield, crates/acre
637
674
699
670
652
66%
94
94
94
834
844
826
829
889
892
891
813
904
833
100
I
I -
-3-
Post emergence to celery and weeds in the field
Karsil (NIA 4562) has controlled emerged annual seedling weeds
in celery fields at up to 3 or 4 weeks after setting. Initially, celery may be
stunted slightly and become slightly chlorotic; however, recovery is prompt and
at harvest check and treated plants have not differed significantly in number
or length of petioles or in yield. Maturity of treated plots may be delayed
from 3 to 5 days and consequently cause a slight retardation in crates per acre
yield. Time of harvest trials are currently underway. Karsil is an experimental
herbicide currently not available commercially. Evaluation data are given in
Table 4 and Table 5.
Table 4. Average evaluation data for post emergence herbicidal
treatments in three celery varieties at three locations. Treat-
ment rates are active material per acre.
Herbicidal treatment
Karsil, 3 Ib.
4 lb.
Karsil, 3 Ib +
Vegadex, 3 lb.
Mineral spirits
50 cpa
Mineral spirits
50 gpa + Vegadex,
3 Ib.
Check, handweeded
Percent control of
Grass B'leaf Sedge
94-72
94-81
97-75
94-94
100
100
Celery
tolerance
97%
96
97-94 100-97 100
81-75 81-25 72
Yield
crates/acre
897
852
917
94 75
- -
100
930
Table 5. Average yields for commercial trials with Karsil post
emergence herbicide applied to four celery varieties at eight
locations.
Herbicidal treatment
Karsil
Karsil + Vegadex
Farm check
Average yields,
6 locations
585
581
628
crates/acre
2 locations
628
643
644
Herbicide Screening
The following information was derived from the most recent trial in
which new herbicides were evaluated (Everglades Station Mimeo Report 60-7).
Diamond Alkali Company DAC-893 and Dow M-1329 had sufficient promise in crop
tolerance and herbicidal performance to warrant further critical evaluation
as pre-emergence herbicides. Robm & Haas FW-734 was an effective post emer-
gence material which tilled all crops but rice. Certain post emergence
herbicide-crop combinations should be tested further in directional applica-
tions. In a comparison of 15 herbicides, crop tolerance was greater and
weed control poorer with granular than with liquid formulations at the same
active ingredient rate. Randox and Vegadex were the only herbicides in which
both formulations were equal herbicidally. Granular amiben was a better herbi-
cide than the liquid formulation.
Primary evaluation of herbicides for leaf crops
Thirty-five chemical treatments were made by applying different for-
mulations, rates and combinations of three herbicides over 18 types and varie-
ties of leaf crops. The crops tolerated CIPC and Vegadex better than Randox.
Randox and Vegadex provided the best weed control. Romaine was injured by
Vegadex. Pink-ribbed endive was severely injured by Randox although green-
ribbed endive grew normally. Three strains of Great Lakes lettuce were less
tolerant to the herbicides than Cornell 456. The Boston lettuces differed in
tolerance.
No firm conclusions may be drawn from this exploratory trial except
that the three herbicides mentioned should be used with caution under field
conditions. Additional research is planned to develop herbicidal treatments,
methods and recommendations satisfactory for commercial use.
Herbicides for sweet corn
Pre-emergence
Corn stand, emergence and growth were normal following pre-
emergence applications of recommended herbicides. Highest yields were obtained
with Simazine, Vegadex, Randao-T and Randox. Best control of grass and brcad-
leaf weeds was provided by Randox, Randox-T and Vegadex. When applied at the
recommended rates (Everglades Station Mimeo Report 60-3) to a 12-inch band in
corn planted on 36-inch centers, these treatments would cost from $3.25 to
6.50 per acre of corn.
Post emergence
The best control of emerged grass and broadleaf weeds in corn
at four weeks after planting was provided by combinations of the following
herbicides: Karsil, Atrazine, and DNBP. Corn was most tolerant of Atrazine
or DNBP alone. However, the best yields were produced in plots treated with
Atrazine, Atrazine + DNBP, DNBP,or Karsil + Randax. None of these are
recommended for commercial use currently. Similar trials are planned to'
develop effective, safe post emergence treatments.
Commercial pre-emergence trials
Several harvester-unit block trials have been established with
cooperators to evaluate pre-emergence herbicides in sweet corn under field
conditions. Randox and Simazine appear to be superior chemicals in trials
which will be harvested in May.
Miscellaneous experiments
Response of celery to gibberelic acid
In a replicated trial gibberelic acid was applied to 52-70 celery
at 0, 10, 20, and 40 ppm at three weeks before normal harvest. The treated and
check plants did not differ in number or length of petioles or in yield of fresh
trimmed plants. Bitterness, fibrousness, flavor and toughness of inner and
outer petioles and preference were evaluated by a panel led by Dr. C. Hall of
the Department of Food Technology and Nutrition at Gainesville. None of these
quality measures was influenced favorably by gibberelic acid treatment and the
check plants were preferred by the panel.
Gibberelic acid was applied to 259-19 celery in non-replicated
demonstration plots. Neither plant measurement, yield nor quality were influenced
favorably by the treatment.
Response of seed potatoes to gibberelic acid slurry treatment
Potassium gibberelate (K GA) slurry treatment was applied to
dormant Red Pontiac whole and split seed potatoes at three rates: none,
recommended (2 oz. of 0.88% K GA per 100 pounds of seed), and twice the
manufacturer's recommended rate (4 oz.). Sprout emergence at three weeks
after planting was increased by seed treatment. Many sprouts were markedly
etiolated and spindly, especially at the higher rate. At six weeks after
planting, stand in split-seed plots was not increased by treatment while
stand in whole-seed plots was increased by K GA. Plants from treated seed
pieces had poorer foliage with small leaves and developed sparse, spindly
and prostrate vines. Yield of tubers greater than 2" in diameter was highest
from non-treated seed. Total yield from whole tubers was increased slightly
by K GA, but total yield from untreated split-seed was more than tw
from K GA treated seed pieces. Tubers were saved from the main crop; held
at 40 F for several months; and then field planted. Emergence and stand
did not differ among plots from check and treated seed.
Current seed dip treatments in gibberelic acid solutions should not
be supplanted by slurry treatments without establishment of more appropriate
dosages. Gibberelic acid is not registered for use on vegetables.
Space seeding of celery with seed sheets
Several techniques for space planting of celery seed in plant
beds have been evaluated. Current research involves controlled random distri-
bution of seed affixed to sheets of soluble fibers. Plantbed populations of
about 60 seedlings per square foot have been grown from seed sheets. The
seedlings have been vigorous and uniform; most plants were taken in one pulling.
EES 60-18
500 copies
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