EFFICACY OF HGW86 APPLIED A ROW DRENCH IN COLLARDS FOR
CONTROL OF CATERPILLAR PESTS
Alton N. Sparks, Jr., Extension Entomologist
University of Georgia, Tifton Campus
P.O. Box 748
Tifton, Georgia 31794
asparks@uga.edu
Introduction
HGW86 is a diamide insecticide, related to Coragen, that is being developed by DuPont.
It has shown good activity against caterpillar pests, both with foliar applications and with
systemic activity through soil applications. This test was conducted at the University of
Georgia’s Horticulture Farm in Tifton, Georgia, to evaluate the efficacy of HGW86 applied as a
greenhouse drench against caterpillar pests of cole crops. Initially this test was also intended to
evaluate efficacy against whiteflies; however, this pest did not appear in sufficient numbers for
potential evaluation until the end of the test when the treatments were losing efficacy and all
treatments were overwhelmed.
Materials and Methods
Collards were transplanted into single row plots (36 inch rows), with 12 plants per plot
(on a 1.5 foot in-row spacing). The experiment was conducted as a randomized complete block
with four replications. HGW86 20SC was applied to the transplants prior to transplanting. Three
rates were evaluated (6.75, 13.5 and 20.25 oz/ac), with the per plant rates calculated based on the
standard row and plant spacings (14,520 plants per acre on 36 inch rows with a 1 foot in-row
spacing). The HGW86 treatments were applied with a repeating pipette in 1 ml of water per plant
applied directly to the root ball. Venom (at 5.6 oz/ac) and Durivo (at 12 oz/ac) were applied as
transplant drenches. Rates were calculated based on standard plant spacings and were applied in
4 oz of water per plant, with the treatment poured onto the root ball and into the transplant hole.
A non-treated control was included for comparison. The greenhouse drenches were applied on 29
July, 2009. Transplanting and the transplant drenches occurred on 30 July.
Five randomly selected plants were visually examined in each plot on each sample date to
determine insect densities. All caterpillars observed were identified and counted. For damaged
plant ratings, all plants in each plot were visually observed for feed damage by caterpillars. All
plants with moderate to severe feeding damage (obvious holes through leaves) were counted.
Data were analyzed with the PROC ANOVA procedure of PC-SAS. Where significant
differences were detected (P<0.05), means were separated with LSD (P=0.05).
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Results and Discussion
Venom showed no effect on caterpillar densities or feeding damage. This treatment was
included as a standard for whiteflies, but this pest was not evaluated. Durivo and all rates of
HGW86 showed excellent efficacy against caterpillar pests. Caterpillars were first detected in the
lowest rate HGW86 treatment, but did not exceed one per 5 plants until 40 days after
transplanting. The highest two rates of HGW86 and Durivo maintained excellent control through
35 to 40 days after transplanting. A clear rate effect was also obvious at 47 days after
transplanting. The Durivo and HGW86 treatments also provided excellent suppression of plant
damage, with less than one plant damaged per plot through 39 days after transplanting. A rate
effect with HGW86 was also apparent in the plant damage counts at 43 and 48 days after
transplanting, but all treatments contained significant damage at that point.
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Table 1. HGW86 Collards Drench Test, Horticulture Farm, Tifton, Georgia, 2009.
Treatment
Drench
Total caterpillars (all species) per five plants
type
5 Aug 11
18
25
31
3 Sept 8 Sept
Aug
Aug
Aug
Aug
6 DAT 12
19
26
32
35
40
DAT
DAT
DAT
DAT
DAT
DAT
Check
0.00 a 0.00 a 1.25 a 3.00 a 6.50 a 8.25 a 10.25
a
Venom
Transpl
0.00 a 0.00 a 1.00 a 2.75 a 5.25 a 6.50 a 12.25
ant
a
Durivo
Transpl
0.00 a 0.00 a 0.00 a 0.00 b 0.00 b 0.00 b 0.50 b
ant
HGW86
Greenho 0.00 a 0.00 a 0.00 a 0.00 b 1.00 b 1.00 b 2.25 b
6.75oz
use
HGW86
Greenho 0.00 a 0.00 a 0.00 a 0.00 b 0.00 b 0.00 b 0.25 b
13.5oz
use
HGW86
Greenho 0.00 a 0.00 a 0.00 a 0.00 b 0.00 b 0.00 b 0.00 b
20.25oz
use
DAT = Days after transplanting
15
Sept
47
DAT
70.00
a
74.25
a
27.50
bc
40.25
b
16.5 c
10.75
c
HGW86 Collards Drench Test, Horticulture Farm, Tifton, Georgia, 2009.
Treatment
Drench type
Number of plants per plot with moderate or severe feeding
damage
24 Aug
27 Aug
7 Sept
11 Sept
16 Sept
25 DAT
28 DAT
39 DAT
43 DAT
48 DAT
Check
6.75 a
6.75 a
11.00 a
11.00 a
11.75 a
Venom
Transplant
7.25 a
8.00 a
11.25 a
11.00 a
11.25 ab
Durivo
Transplant
0.00 b
0.25 b
0.75 b
1.75 c
8.00 c
HGW86 6.75oz
Greenhouse
0.75 b
0.25 b
0.75 b
3.75 b
10.00 b
HGW86 13.5oz
Greenhouse
0.00 b
0.25 b
0.50 b
1.75 c
8.25 c
HGW86 20.25oz Greenhouse
0.00 b
0.00 b
0.75 b
0.75 c
4.25 d
DAT = Days after transplanting
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