Department of Agricultural Entomology, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai625104, Tamil Nadu, India.
The allelochemical contents viz., total phenols, gossypol and tannins in different plant parts (leaves, squares and bolls) of selected cotton varieties / hyhirid maintained under rainfed condition were biochemically analysed by following Folin-Ciocalteau reagent method, phloroglucinol reagent method and Folin-Denis methods, respectively. Correlation analysis was carried out to know the relationship between the pest incidence and allelochemical contents in plants. Total phenol and gossypol contents were more in squares followed by bolls and leaves, whereas, tannin content was higher in squares followed by leaves and bolls in all the selected varieties / hybrid. The total phenol, gossypol and tannin contents in different plant parts (leaves, squares and bolls) of different cotton varieties / hybrid showed significant negative relationship with the incidence of leafhoppers, aphids, whiteflies, thrips, American bollworm, spotted bollworm and pink bollworm.
Allelochemical contents, pests, cotton
