2007 Extension Research Report
Insect Management
EVALUATION OF INSECTICIDES IN BROCCOLI 2006
David G. Riley, University of Georgia, Tifton Campus, Department of Entomology, Tifton, GA
31793, dgr@uga.edu
Introduction
Broccoli is currently a relatively low
acreage Brassica crop that is being considered by
more Georgia vegetable growers in recent years,
but it is faced with the same pests that attack
cabbage and collards, namely, diamondback moth
(DBM); Plutella xyllostella, cabbage looper (CL);
Trichoplusia ni, imported cabbage worm (ICW);
Pieris rapae, and tobacco thrips Frankliniella
fusca. The test evaluated some of the newest
products labeled and not yet available for this
crop.
Mature broccoli heads were harvested from 30 ft
of row on 8 and 31 May and fruit were
categorized as not (0), very slightly (1), slightly
(2), moderately (3), heavily (5) and severely
damaged (6) and the average weight was
measured. Damage ratings for the overall
harvested plot and individual heads (for the last
harvest) were recorded. Any damage was
considered unmarketable because of the presence
of insects in the head. Data was analyzed using
GLM and LSD tests for separation of means (SAS
Institute 1985).
Materials and Methods
Broccoli was transplanted into two 50 ft
rows per 6-ft wide beds on 30 March 2006 and
maintained with standard cultural practices at the
Lang Farm, Georgia Coastal Plain Experiment
Station at Tifton. A total of 500 lbs of 10-10-10
was applied to Tift pebbly clay loam field plots
and 140 lbs of ammonia nitrate was sidedressed.
Irrigation was done weekly with an overhead
lateral sprinkler system. Scouting was initiated on
23 April and continued weekly until harvest. The
focus of the scouting was on DBM and CL, by
early instar ICW were recorded to keep separate
from DBM counts. Six applications of insecticide
were made on 6, 13, 20, 27 April and 4, 12 May.
Two samples of 6 plants were scouted per plot
approximately 48 h after weekly applications.
Results and Discussion
All of the treatments were efficacious
against lepidopteran pests in this trial although the
rotation treatment 7 did not provide adequate
protection against damage. In general, the damage
ratings corresponded with the level of total
Lepidoptera larvae control. The treatments of
Avaunt and the rotation provided good control of
diamondback moth larvae, but still had slight
losses in marketable yield. The newer products,
E2Y45 and Experimental, provided excellent
control of Lepidoptera larvae and the greatest
marketable yield of broccoli. There was no
significant rate response, just a tendency of lower
weight with the lowest rate of E2Y45 and less
DBM control on a single date, 5/23/06.
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Treatment - rate lb ai per acre
DBM per 6
plants on
4/23/06
DBM per 6
plants on
5/8/06
DBM per 6
plants on
5/23/06
DBM small
larvae per 6
plants on
5/30/06
DBM large
larvae per 6
plants on
5/30/06
Avg. number
of total CL
larvae per 6
plants
Avg. number
of total ICW
larvae per 6
plants
1. DPX-E2Y45 1.66SC 0.044 lb ai/a
0.00 b
0.13 b
0.75 ab
0.00 b
0.00 b
0.0 b
0.08 a
2. DPX-E2Y45 1.66SC 0.066 lb ai/a
0.00 b
0.25 b
0.00 b
0.00 b
0.00 b
0.0 b
0.38 a
3. DPX-E2Y45 1.66SC 0.088 lb ai/a
0.13 b
0.00 b
0.00 b
0.00 b
0.00 b
0.0 b
0.33 a
4. Experimental rate 1
0.13 b
0.38 b
0.00 b
0.00 b
0.00 b
0.0 b
0.08 a
5. Experimental rate 2
0.00 b
0.88 b
0.00 b
0.00 b
0.00 b
0.0 b
0.17 a
6. Avaunt 30 WDG 0.065 lb ai/a +
DPX-E2Y45 1.66SC 0.044 lb ai/a
0.00 b
0.00 b
0.00 b
0.00 b
0.00 b
0.0 b
0.17 a
7. Proclaim 5 WDG 0.015 lb ai/a
Avaunt 30 WDG 0.065 lb ai/a
Spintor 2SC 0.0156lb ai/a (rotation)
0.63 b
0.63 b
0.00 b
0.00 b
0.00 b
0.0 b
0.33 a
0.09 a
0.58 a
8. Untreated Check
2.25 a
3.00 a
2.00 a
0.43 a
0.29 a
* Means within columns followed by the same letter are not significantly different (LSD, P<0.05).
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Treatment - rate lb ai per acre
Avg. number
of total DBM
larvae per 6
plants
Avg. number
of total Lep.
larvae per 6
plants
Avg. wt.
(lbs) of
marketable
heads
harvested
Total number
marketable
heads harvested
per 30 ft of row
Total number
of damaged
heads
treatment
Total number
heads
harvested per
30 ft of row
1. DPX-E2Y45 1.66SC 0.044 lb ai/a
0.3 b
0.2 a
7.7 b
22.3 ab
0.75 b
23.0ab
2. DPX-E2Y45 1.66SC 0.066 lb ai/a
0.2 b
0.6 a
9.4 ab
24.8 a
0.0 b
24.8 a
3. DPX-E2Y45 1.66SC 0.088 lb ai/a
0.1 b
0.4 a
8.1 ab
22.5 ab
0.0 b
22.5 ab
4. Experimental rate 1
0.1 b
0.3 a
9.0 ab
23.8 ab
1.0 b
24.8 a
5. Experimental rate 2
0.3 b
0.6 a
10.6 a
24.3 a
0.8 b
24.3 ab
6. Avaunt 30 WDG 0.065 lb ai/a +
DPX-E2Y45 1.66SC 0.044 lb ai/a
0.1 b
0.2 a
8.3 ab
18.0 bc
0.5 b
18.5 bc
7. Proclaim 5 WDG 0.015 lb ai/a
Avaunt 30 WDG 0.065 lb ai/a
Spintor 2SC 0.0156lb ai/a (rotation)
0.4 b
0.9 b
4.9 c
14.3 c
2.0 ab
16.3 c
3.5 a
15.8 c
8. Untreated Check
1.54 a
2.4 a
4.3 c
12.3 c
* Means within columns followed by the same letter are not significantly different (LSD, P<0.05).
** Treatment effect marginal (P=0.1).
87