Physiological and biochemical basis of PGR’s induced insect resistance in cotton

Abstract

The experiment on physiological and biochemical basis of PGRs induced insect resistance in cotton wasconducted during kharif 2018 at ARS, Dharwad farm, UAS, Dharwad. The experiment consisted of seven sub plottreatments (T1: Control T2: CCC 50 ppm, T3: CCC 100 ppm, T4: SA 50 ppm, T5: SA 100 ppm, T6: MC 50 ppm and T7:MC 100 ppm) maintained at two main plot treatments (M1: Sucking pest protected and M2: Sucking pest unprotected) laidin split plot design with three replications. The sucking pest susceptible non-Bt cotton genotype, Suraj was grown withrecommended package and PGRs are sprayed at 60 DAS. Pesticides for sucking pests were sprayed only for treatments ofprotected condition. Periodical, morphological, biochemical and pest load parameters were recorded along with yield andyield attributes.Foliar application of MC at 100 ppm recorded significantly lower pest load (Thrips-23.87, Aphids-7.3,Jassids-24.5) lower reducing sugar (4.51 mg /g fr.wt.), lower protein content (8.04 mg /g fr.wt.), higher phenol (3.96 mg /gfr.wt.) and gossypol content (33.83 μg /g fr.wt.) under protected condition over other treatments. However, foliar spray ofSA at 100 ppm recorded significantly more boll numbers (45.38), boll weight (4.79 g), seed cotton yield (19.16 q ha-1) andharvest index (42.44%) compared to other treatments including control