Varietal resistance of cotton against Earias spp.
2003
Abro, G.H. | Syed, T.S. | Dayo, Z.A. (Sindh Agriculture Univ., Tandojam (Pakistan). Dept. of Entomology)
Studies were carried out on varietal resistance of cotton against Earias spp. during cropping season 1999. The seeds of 12 cotton varieties viz., Green Red Okra, Qalandri, Red Okra-VI, Red Okra (Insect Resistant), AENS- 1/82 VIII, Red Okra, TH-228/87, AENS-10/87, TH-3/83, Reshmi, AEC- 7813/89 and TH-41/83 were sown on April 22, 1999 in a completely randomized design with strip cropping, each strip measuring 20 x 35 feet with nine rows of each variety. Observations on infestation of Earias spp. were started 67 days after sowing and continued till complete disappearance of pest from the crop. Observations were taken at random at weekly interval from 20 plants. The results revealed that there was no significant difference of infestation amongst cotton varieties under present investigation. The minimum and the maximum infestation of 1.79 and 2.38 % was recorded on Red Okra-VI and Green Red Okra varieties of cotton, respectively. The results also indicated that there was no significant effect of minimum and maximum temperature on percent infestation of Earias spp., whereas relative humidity had a significant (P less than 0.05) effect on infestation.
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