Factors to Consider When Choosing a Corn Rootworm Soil Insecticide
 
Organophosphates**
Pyrethroids
Phenylpyrazol
 
chlorethoxyphos
(Fortress 5G)
3.0 oz/1000 row ft
chlorpyrifos
(Lorsban 15G & generics)
8.0 oz/1000 row ft
tebupirimphos & cyfluthrin
(Aztec .1G)
6.7 oz/1000 row ft
terbufos
(Counter CR)
6.0 oz/1000 row ft
tefluthrin
(Force G3)
4-5 oz/1000 row ft
fipronil
(Regent 4 SC)
0.24 fl oz/1000 row ft

Performance: test plots-
band application
  Root damage rating1,2
  Consistency of performance (%)3


2.9cd
79


2.8bcd
90


2.3ab
94


2.1a
95


2.3ab
100


n/a
n/a
Performance: test plots - infurrow application
  Root damage rating1,2
  Consistency of performance (%)3


2.8bcd
85


2.6abc
86


2.2a
92


2.4ab
93


2.3ab
100


3.15d
83

1Average root damage rating (Iowa 1-6 scale) in 6-19 tests over five years, where damage in the untreated plots exceeded 3.5, the damage level above which economic losses are likely to occur. The untreated plots averaged 4.79. Only three years data available for Regent 4SC.
2Values followed by the same letter are not significantly different according to Ryan-Einot-Gabriel-Welsch-Qtest (P<0.10).
3Percentage of tests where average damage rating was less than 3.5 when the untreated equaled or exceeded 3.5. Tets from 1994-2000. There were no data in 1996 and 1998.
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