Wireworm - Spindletop 2006

Ric Bessin = Extension=20 Entomologist, Department of Entomology, University of Kentucky

WIREWORM CONTROL IN NO-TILL CORN, = 2006:=20 Fifteen insecticide treatments were evaluated for control of wireworm = larvae,=20 primarily Melanotus depressus. =20 The test plot was planted following soybeans the previous year on = the UK=20 Spindletop Research Farm in Fayette Co., KY, = on 18 Apr=20 as a RCB with 4 replicates. = There=20 has been a history of wireworm damage in this particular field. = Individual=20 sub-plots consisted of single row of corn, 25 m long, with 76.2 cm row = spacing.=20 The corn hybrid used for all treatments was N67-D6 at a seeding rate of = 34,500=20 kernels per acre. All insecticide treatments were applied at planting = except the=20 seed treatments which were custom applied prior to the seed before=20 planting. Stand counts = from the=20 center 18.3 m were recorded on 2, 8, 18, May, and 8 Jun. Extended leaf heights = were recorded=20 from 10 plants in each plot on 18 Jun. Data were subject to ANOVA and = treatment=20 means compared by LSD (SAS Institute).

Treatment

Rate

Stand=20 Counts

Extended=20

Leaf=20 Height

6/18/06

Yield (bu/acre)

5/02

5/08

5/18

6/08

Untreated

25,700=20 h

26,281 gh

25,047 gh

24,611=20 f

142.2 bcd

99.9 abcd

Fortress 5G=20 SB

1.0 oz / 1000 ft=20

(infurrow)

26,136 gh

26,063=20 h

25,047 gh

24,539=20 f

139.9 bcd

100.1 abcd

Fortress 5G=20 SB

1.5 oz / 1000 ft=20

(infurrow)

26,789 efgh

26,862 fgh

26,209 efgh

25,918 ef

144.5 abcd

118.8=20 a

Fortress 5G=20 SB

2.0 oz / 1000 = ft

(infurrow)

27,225 efgh

27,080 efgh

25,555 gh

25,846 ef

139.9 bcd

88.1 bcd

Aztec 4.67G=20 SB

1.0 oz / 1000 ft=20

(infurrow)

24,974=20 h

26,136=20 h

24,974=20 h

24,394=20 f

139.9 bcd

108.6 abcd

Aztec 4.67G=20 SB

1.5 oz / 1000 ft=20

(infurrow)

26,739 efgh

27,225 efgh

25,918 fgh

26,572=20 def

142.7 abcd

118.6=20 a

Aztec 4.67G=20 SB

2.0 oz / 1000 = ft

(infurrow)

28,024 defg

28,750=20 def

27,370 defgh

27,443 cde

146.7 abc

122.6=20 a

Poncho=20 250

0.25=20 mg/kernel

31,000 abc

31,218 abc

30,710 abc

30,202 abc

138.3 cd

127.7=20 a

Capture LFR = 1.5=20

Poncho=20 250

3.4 fl oz /=20 acre

0.25=20 mg/kernel

28,387 defg

28,677 defg

28,822 bcd

27,951 bcde

148.5 ab

80.6=20 d

Capture LFR=20 1.5

3.4 oz /=20 acre

28,604=20 def

28,677 defg

28,532 bcde

28,024 bcde

148.2 abc

87.1 cd

Cruiser

0.25=20 mg/kernel

29,621 bcd

29,113 cdef

28,750 bcde

28,532 bcde

136.0=20 d

116.1 ab

A14115

Cruiser

0.125 mg=20 /kernel

0.125=20 mg/kernel

31,291 ab

32,089 ab

31,073 ab

30,637 ab

147.5 abc

111.5 abc

Force 250=20 GA/L

8 fl=20 oz/a

26,426 fgh

28,024 efgh

27,588 defg

26,935=20 def

152.6=20 a

107.8 abcd

Poncho=20 1250

1.25=20 mg/kernel

33,178=20 a

33,541=20 a

32,960=20 a

31,944=20 a

143.0 abcd

110.3 abc

Force 3=20 G

4=20 oz/1000'

28,967 cde

29,330 cde

28,314 cdef

29,330 abcd

140.7 bcd

111.7 abc

Cruiser

1.25 mg=20 /kernel

29,911 bcd

30,565 bcd

29,766 bcd

29,185 abcd

142.5 bcd

111.7 abc

In=20 general, the higher rates of Aztec and Fortress improved stands when = compared to=20 the below labeled rates. We do not ever recommend using pesticides at = rates=20 above or below those listed on the label, but we may include those for = research=20 and demonstration purposes. The other treatments in the study all = improved=20 stands when compared to the untreated control. The higher rates of = Poncho and=20 Cruiser also improved stands and vigor.

This=20 study indicates that producers need to match the technology for wireworm = control=20 with their specific field needs (the potential for stand loss in that = field) and=20 with their available equipment.

From = University of = Kentucky, Extension Entomology = Research=20 Reports at: http://pest.ca.uky.e= du/EXT/Res/ResPubs.shtm