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

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.