Integration of Resistant Mutants with Neem Extract in Cotton Insect Control

Abstract

The studies at Suwan Farm during 1997-98 and 1998-99 were set up to show exp.2 with the application of neem extract integrated with cotton resistant variety lines as the insect control method to give better yields than those obtained in exp.1 using resistant plant as principal control alone. AP1 and AP2, the mutant lines possessing antibiosis mechanism against some major insect pests of cotton and SR60, the recommended variety were used in the test. It was found that the average amount of jassids on the mutants and SR60 in exp.1 did not significantly differ from those in exp.2 while there are significant differences between the numbers of bollworm and cotton plant bug on each variety/line of both tests. The comparison of average seed yields also revealed highly significant increase of seed weight in AP1 and AP2 in exp.2 whereas the increase in SR60 was not that high. Concerning fiber quality parameters, fiber length of all variety/line in both experiments were in medium group with their uniformities and micronaires to be very high and desirable respectively.