Insecticide Use (continued)

The sunflower head moth was the targeted insect for methyl parathion use by 73% of KS respondents who used it, followed by the banded sunflower moth by 18% and the seed weevil by 9%. The sunflower head moth was the targeted insect for all parathion use by 81% of KS, respondents, followed by the banded sunflower moth by 14% and the seed weevil by 5% (Table 21). Parathion was applied by air by all reporting respondents in KS and SD (Table 22).

Methyl parathion was used at 1-4 fl oz/A by 39% of KS respondents, at 8 fl oz by 23%, at 16 fl oz by 15% and above 16 fl oz by 23% (Table 23). Eight percent of respondents reported using methyl parathion at a rate of 32 fl oz/A. Parathion efficacy was reported to be excellent by 18%, good by 36%, fair by 36% and poor by 9% of KS reporting respondents (Table 20). Labeled rates for methyl parathion 8EC were 8 to 16 fl oz/A, and for methyl parathion 4EC was 32 fl oz/A. Only the 8 pound formulation is now available.

The sunflower head moth was the targeted insect for Warrior use by 69% of KS respondents who used it, followed by the stem weevil by 13%. The sunflower beetle was the targeted insect for Warrior use by 67% of ND respondents who used it, followed by the stem weevil for 19% and the seed weevil by 8% (Table 24). Warrior was applied by air by 90% of KS, 71% of ND and 71% of SD respondents (Table 25).

Warrior is labeled for use at 1.28-2.56 fl oz/A for control of sunflower beetle and at 2.56-3.84 fl oz/A for control of stem weevil and head moth. It was used at less than 1 fl oz/A by 27% of ND respondents and at 1.0-1.27 fl oz by 23% of ND respondents (Table 26). Thus, 50% of ND respondents used Warrior at below-label rates. Warrior was used at the label rates for sunflower beetle of 1.28-2.56 fl oz/A by 23% of KS and 41% of ND respondents; it was used at the 2.57-3.84 rate for other sunflower insects by 62% of KS and 5% of ND respondents. These differences in use patterns between KS and ND reflect the differences in pest problems, with 67% of ND respondents using Warrior for the sunflower beetle. In spite of low use rates, Warrior efficacy was rated excellent by 42% of KS and 63% of ND respondents and good by 58% of KS and 29% of ND respondents. It was rated as fair by only 7% of ND respondents (Table 20).

Respondents in all four states reported using crop rotation as a means of non-chemical insect management. This practice was reportedly used on 41% of KS, 74% of MN, 59% of ND and 75% of SD respondents' acres. Tillage was reported as a means of non-chemical insect management on 14% of KS, 22% of MN, 30% of ND and 41% of SD respondents' acres. Hybrid selection was reported as a means of non-chemical insect management on 3% of KS, 23% of MN, 10% of ND and 26% of SD respondents' acres (Table 27). The use of crop rotation is similar to use patterns in 1994, but the use of tillage was higher in 1997 than in 1994 in MN and SD (4).