) AGRICULTURAL RESEARCH CENTER
S Hastings, Florida
), "/- /
POL Mimeo 71-11 October 1971
NEMATODE CONTROL ON WINTER GROWN CABBAGE
IN THE HASTINGS, FLORIDA AREA
D. P. Weingartner, Asst. Plant Pathologist
Agricultural Research Center
D. W. Dickson, Asst. Nematologist
Entomology and Nematology Dept.
Soils cultivated to cabbage in the Hastings, Florida area have been shown to
be heavily infested with plant parasitic nematodes. The nematode genera
found most frequently are: Meloidogyne (root knot), Belonolaimus (sting),
Trichodorus (stubby root), Tylenchorhynchus (stunt), Helicotylenchus (spiral),
Hemicyliphora (sheath), and Criconemoides (ring). In addition some fields
are heavily infested with Scutellonema, Pratylenchus (root-lesion) and
Dolichodorus (awl) nematodes.
In preliminary tests performed in 1969, fresh weights of cabbage seedlings
grown in seed beds heavily infested with plant parasitic nematodes were
significantly increased by nematicide treatments in some, but not all beds.
The majority of the cabbage crop is planted in the Hastings area between
mid September and late November when soil temperatures are relatively warm
(700- 900 F). The crop matures in relatively cool (550- 750 F) soil. Soil
moisture content is often high during this part of the cabbage growing season.
It has not been determined whether plant parasitic nematodes actively feed
and increase to damaging levels on cabbage grown under such conditions.
An experiment was conducted during the 1970-71 growing season to determine:
(a)whether plant parasitic nematodes reduce yields of early to mid-season
direct-seeded cabbage; and (b)whether' relatively low rates of soil fumigants
would increase cabbage yields.
METHODS AND MATERIALS:
The sorghum cover crop was knocked down during the first week in September,
1970 and chopped with a tandem two-row stalk chopper. The land was rotivated
September 16. Soil fumigants [Telone (5 and 7 GPA), D-D (10 GPA), Vorlex
(7 GPA), and Fumazone 86 (2.5 GPA)] were applied with gravity flow equipment
October 2. Fumazone 86 (0.8 GPA) was applied October 21. Beds were shaped
October 21 and direct-seeded with cabbage cv. Head Start October 22. Plants
were harvested February 15, 1971.
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Data from the experiments are summarized in Table 1. Soil fumigants signi-
ficantly reduced populations of parasitic nematodes and significantly increased
yields of cabbage when compared to nontreated controls. Telone (7.0 GPA),
D-D (10.0 GPA), and Vorlex (7.0 GPA) provided best nematode control. Greatest
economic returns resulted from treatment with Telone (7 GPA), D-D (10 GPA) and
Fumazone 86 (0.8 GPA). Nematode control during the early seedling stage was
important. Improved vigor due to treatment was observed by November 23. Vigor
ratings made November 23 and December 9 were highly correlated with yield.
Nematode populations did not increase between December 2 and harvest. Soil
temperatures were low (300 500 F) due to a general cooling trend and four
separate freezes. It appears likely that nematode feeding and reproductive
activities were minimal during this period.
DISCUSSION AND CONCLUSIONS:
Based on these data, soil fumigation for control of nematodes is suggested for
cabbage which is direct-seeded in the Hastings area during August December.
Soil fumigation has not been tested on transplanted cabbage in the Hastings
area. It appears likely that fumigation would increase yields, however, it is
not known to what degree. Soil fumigation of transplanted cabbage should be
done only on limited acreage until it is determined that such treatment is
economical. Only seedlings obtained from fumigated seedbeds should be trans-
planted into fumigated soils.
GENERAL INFORMATION CONCERNING SOIL FUMIGATION:
1. Cover crops should be well decomposed before soil is fumigated. Cover
crops should therefore be disked under at least 4-6 weeks before fumigating.
2. Soil fumigants (except DBCP) must be applied as preplant treatments. The
materials must be applied 3-4 weeks before planting and soil should not
be disturbed for 7-10 days following treatment.
3. The preplant waiting period should be extended if heavy rains and/or low
temperatures occur following soil fumigation. In addition, soil should
be reworked before planting.
4. When using soil fumigants (or any other pesticide), READ THE LABEL CAREFULLY
AND EXPLICITLY FOLLOW DIRECTIONS!!
5. Remember failure to allow soil fumigants to diffuse from soil can result
in crop injury.
POL 71-11 Page 2
Tiole 1. Results of 1970-71
nematode control experiment on direct seeded cabbage.-
2/ Head 4/ Increase in Net
Rate Weight Yield Vigor Rating Nematodes in Crop Value Return
Treatment (GPA) (Ibs.) (Ton/A) Nov. 23 Dec. 9 100cc Soil ($/A) ($/A)
Telone 5.0 1.73 8.8 3.3* 6.4 17.4* 18 -3.37
Telone 7.0 1.91 11.3** 3.4* 6.8* 5.2** 168 56.83
D-D 10.i 2.08** 10.7** 3.4* 6.9* 8.2** .132 38.97
Vorlex 7.0 2.20** 10.8** 3.6** 7.2* 1.2** 138 8.11
Fumazone 86 0.8 1.83 9.9* 3.0 6.6 23.8 84 25.86
Fumazone 86 2.5 1.78 9.8 3.3* 6.7 23.4 78 2.57
Control Mean 1.72 8.5 2.7 6.2 57.4 -
1/ A3l data represent mean values of 5 replications from randomized block design. Values varying
significantly from mean of controls are indicated by ** (1% level) and (5% level), respectively.
2/ hates = material applied/row acre = 13070 linear feet.
3/ Vigor rating based on 1-10 with 1 being least vigorous.
V/ Sum populations of sting, stunt, and stubby root nematodes in mid-season soil samples.
5/ Net return = increase in crop value minus cost of material plus added cost to harvest and market. All
calculations based on $1.50/bag (0.03/lb.) at harvest. Chemical costs based on dealer's price list
March 17, 1971. Marketing costs ($0.864/50 lb.) taken from Ag. Econ. Report 15 (Costs and Returns
from Vegetable Crops in Florida Season 1969-70 with Comparisons). Page 3.
6/ Fumazone 6 (0.8 GPA) applied at planting.