Asian Journal of Bio Science

K. Kumar ¹, G. Santharam ²

Affiliations
1 Department of Entomology, Pandit Jawaharlal Nehru College of Agriculture and Research Institute, Karaikal, Puducherry (U.T.), IN
2 Department of Entomology, TamilNadu Agricultural University, Coimbatore (T.N.), IN

Abstract

Chemical insecticides have been the backbone of insect pest control since the early 1950’s when organochlorine insecticides were first widely introduced. Indiscriminate use of the chemical insecticides which are active against a broad spectrum of insects led to many ecological problems. Chemicals are to be used judiciously which serve as a major tool in pest management.

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K. Kumar ¹, G. Santharam ², R. Sridhar ³

Affiliations
1 Department. of Agricultural Entomology, P.J.N.College of Agriculture and Research Institute, Karaikal (Puducherry), IN
2 Department of Entomology, TamilNadu Agricultural University, Coimbatore ( T. N.), IN
3 Department of Microbiology, TamilNadu Agricultural University, Coimbatore ( T.S N.), IN

Abstract

In cotton, the compatibility of imidacloprid as seed treatment was evaluated with plant pathogenic antagonistic microorganisms, Trichoderma viride (Pers) and Pseudomonas fluorescens (Migula). The radial growth of T. viride was less at higher concentration of 7000 ppm (12.5mm) compared to the untreated check (15.1mm) at 24 h. The radial growth was less in treatments compared to untreated check at 48 and 72 h of incubation. Similarly the spore yield was less in treatments compared to untreated check. Regarding the bioefficacy of T. viride, the radial growth of the pathogen, Macrophomina phaseolina was 20 mm in the treatment of T. viride alone while it was 38 and 40 mm in the combination treatments of imidacloprid 70 WS at 7 g and 5 g kg-1 with T. viride 4 g kg-1while in the untreated check it was 45 mm. In the pot culture studies, it was found that the population of T. viride was higher in the treatment of T. viride 4 g kg-1alone compared to the combination treatment of imidacloprid 70 WS and T. viride. Similar trend was also observed in case of P. fluorescens. It was concluded that imidacloprid was having lesser impact on T. viride and significant inhibitory effect on P. fluorescens.

Keywords

Cotton, Trichoderma viride, Pseudomonas fluorescens, Imidacloprid.

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