Impact of adding chitosan on bioefficacy of insecticides against cotton spiny bollworm Earias insulana (Lepidoptera: Noctuidae)‎ infesting cotton bolls and yield measurable under field conditions

Abstract EN

Cotton spiny bollworm (SBW) Earias insulana (Boisduval) (Lepidoptera: Noctuidae) is important pests of cotton.

Its larvae bore into the growing shoots, flower buds, flowers and bolls of cotton resulting in considerable losses in quality and quantity.

The aim of this research work is to study, adding impact of chitosan as newcomer material on bioefficacy of some insecticides against E.

insulana infesting cotton bolls and on cotton yield measurable.

The results of statistical analysis showed there are highly significant differences in case 1st and 2nd spray with initial and residual effect.

In case initial effect , Tracer + chitosan come in the first group recorded 75.33 reduction % followed by indoxacarb ( 52.00), chitosan ( 47.09), runner ( 34.67 ), indoxacarb + chitosan (43.48), runner + chitosan ( 24.33) and tracer alone ( 16.29) reduction % , respectively.

On the other hand , adding chitosan to indoxacarb increase residual effect to indoxacarb recorded 74.53 reduction %, compared with other treatments , while chitosan alone recorded less reduction % 37.36 against larvae of E.

insulana .

The 2nd spray, chitosan spray on cotton bolls recorded highest reduction % 75.51 % in case initial effect.

But , indoxacarb + chitosan come in the first category 81.13 % reduction in residual effect.

In addition to , runner + chitosan and tracer recorded the highly number of healthy bolls 8.8 and 8.2 bolls / plant and in case of boll weight, indoxacarb + chitosan record 3.40 gm / bool followed by indoxacarb 3.18, runner 2.26, control 2.89 , runner + chitosan 1.97, tracer 1.96, chitosan 1.93 and tracr + chitosan 1.44 gm / boll .