Low dosages of gamma irradiation of seed increase the growth and yield of two cultivars of sunflower

Abstract

Seeds of cv. Restoler and Noor of sunflower (Helianthus annuus L.) were subjected to 0.5 to 50 krad 60Co gamma radiation (1 rad = 10 mGy) and grown to maturity in a greenhouse. Two low dosages, i.e., 1 krad in cv. Restoler and 3 krad in cv. Noor, caused statistically significant stimulation of vegetative growth and seed yield (both total number and weight). For cv. Noor, 3 krad also significantly stimulated the weight of an individual seed. Significant declines in the yield of mature seeds occurred only at critical dosages of > 10 to 20 krad.