Yield loss estimation in safflower due to aphid, Uroleucon compositae (Theobald)

Abstract

The field experiment, conducted with five safflower varieties during rabi 2015-16 under protected and unprotected conditions, revealed that the variety A-1, showing greater degree of tolerance/ resistance to aphids, recording the least number of aphids per plant (83.20 aphids 5 cm apical twig-1) followed by A-300 (86.35 aphids 5 cm apical twig-1) and A-2 (92.20 aphids 5 cm apical twig-1), recorded the highest yield of 10.8 q ha-1, 10.41 q ha-1, 9.33 q ha-1, respectively). Whereas, PBNS-12 and non-spiny Nari-6, the most susceptible ones, recording maximum number of aphids (103.45 and 119.50 aphids 5 cm apical twig-1, respectively). yielded the lowest of 8.81 q ha-1 and 8.52 q ha-1, respectively under protected condition. The yield under unprotected condition was highest in A-1 (7.73 q ha-1) followed by A-300 (7.14 q ha-1) and A-2 (6.96 q ha-1), lowest in PBNS-12 (6.56 q ha-1) and Nari-6 (6.224 q ha-1). Per cent losses in unprotected over protected condition were highest in variety A-300 (45.80%) followed by A-1 (39.72%), Nari-6 (36.54%), PBNS-12 (34.30%) and A-2 (34.05%). The loss in yield due to safflower aphid alone ranged from 34.05 to 45.80 per cent across varieties.