Vol.18_No.2 - Pesticide Alternatives Lab - Michigan State University
Vol.18_No.2 - Pesticide Alternatives Lab - Michigan State University
Vol.18_No.2 - Pesticide Alternatives Lab - Michigan State University
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Spring 2009 Resistant Pest Management Newsletter Vol. 18, No. 2<br />
Effect on Bollworm Incidence<br />
The mean percent reduction over control on<br />
boll incidence at recommended dose of quinalphos was<br />
36.6, 31.5, 39.4, 40.8 and 27.5 on square, boll, locule,<br />
interlocular and bad kapas basis respectively. At the<br />
highest dose of 10X RD, the mean percent reduction<br />
over untreated check was 51.8, 54.1, 76.7, 65.4 and<br />
58.6 and at lower doses percent reduction over control<br />
was 19.3, 9.7, 13.4, 11.3 and 9.2 at 1/3 RD and 30.7,<br />
21.2, 22.3, 21.6 and 14.3 at 1/10 RD on square, boll,<br />
locule, inter locular and bad kapas basis respectively<br />
(Table 4.).<br />
The larval recovery from 200 implanted eggs<br />
before second application of quinalphos ranged from<br />
102 to 136 larvae per hundred plants. Recommended<br />
dose of quinalphos resulted in a 42.1 percent reduction.<br />
Increase in dose by 10 times resulted in a percent<br />
reduction of 84.6 and a decrease in dose resulted in<br />
decreased percent reduction; 29.8 (1/3 RD) and 21.4<br />
(1/10 th RD). The resistance level of spray survived F 1<br />
population ranged from 46.0 – 58.7 percent when<br />
compared to 47.1 prior to the application (Table 3).<br />
RD: Recommended dose<br />
Figures in parentheses are arc sine percentage transformed values.<br />
Means followed by the same letter are not significantly different by<br />
DMRT (P = 0.05).<br />
Effect on A. gossypii<br />
The population level prior to application of<br />
quinalphos varied from 22.0 to 27.5 per three leaves.<br />
At recommended dose the reduction was 41.3 – 41.6<br />
percent and increase in dose up to 10 times affected<br />
increased reduction (53.6 – 55.2). At lower doses the<br />
mean percent reduction was 20.6 – 24.5 (1/3 rd RD) and<br />
12.0 - 13.7 (1/10 th RD) (Tables 5).<br />
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