Abstract
The corn leaf aphid (CLA), Rhopalosiphum maidis (Fitch) is one of most serious pest of barley, Hordeum vulgare L. in northern plains of India. The resistant to CLA has been identified in both two and six rowed barley genotypes. Comparative biology, no-choice test and population build up studies were conducted to determine variation in level of aphid resistance in five selected barley genotypes BCU 2806, BK 9816, CIHO 6264, BCU 4507 and IC 434880 along with susceptible check PL 426. The nymphal duration and adult longevity of CLA was significantly higher on resistant barley genotypes whereas these genotypes has relatively lower fecundity and mean reproductive potential. BK 9816 (15.07 ± 1.44 days) and IC 424880 (15.08 ± 1.73 days) has the longest nymphal duration and BCU 2806 has the longest adult longevity (19.63 ± 1.20 days) of CLA. The reproductive potential of CLA was minimum on BCU 2806 (2.24±0.19 nymphs/day) and fecundity was lowest on BK 9816 (31.10±1.60 nymphs). The population build-up of CLA on resistant genotypes has been delayed by a week. Higher mortality and early alate formation in no-choice test indicated the presence of both antixenosis and antibiosis type of resistance in tested resistant barley genotypes.
Keywords
Comparative biology, Barley, Corn Leaf Aphid, genotypes, Rhopalosiphum maidis (Fitch)