Development of lentil (Lens culinaris) genotypes resistant to pea aphid, Acyrthosiphon pisum (Hemiptera: Aphididae) under field condition

Development of effective and sustainable pea aphid (Acyrthosiphon pisum) management methods are required because it causes yield loss of 26% in lentil (Lens culinaris) through direct feeding and indirectly by transmitting several viral diseases. The aim of this study was to verify field resistance of lentil genotypes to pea aphid in locations that had different altitudinal ranges but similar cropping system. A pea aphid susceptible check variety EL-142 and eight resistant lentil genotypes were tested at four locations for four seasons in randomized complete block design with three replications. Seeds were sown in rows at the rate of 65 to 80 kg ha^-1 and recommended planting date for each location. Pea aphid was sampled by beating the plants on a board that had six 10 cm× 13 cm (20 cm × 39 cm) rectangles. The seasonal pattern of pea aphid density build up was similar on both resistant and susceptible lentil genotypes. However, in seasons and locations where the pea aphid infestation was severe, the susceptible check had two to four times greater pea aphid density than the pea aphid resistant genotypes. Moreover, the percentage yield reduction was positive for all resistant genotypes and it ranged from 5.5 to 93.9%. The resistant lentil genotypes reduced the pea aphid density and gave higher (up to 1456 kg ha^-1) grain yield than the susceptible check (as low as 45 kg ha^-1). Thus, the resistant genotypes can be used independently or in combination with other pea aphid management tactics as required.