The Effect of Supplemental Irrigation and Cultivars on Population of Safflower Fly (Acanthiophilus Helianthi Rossi.)

Damage caused by water shortages leads to physiological and biochemical changes in metabolism of plants and make them predispose to attack by pests and diseases and reduce the quality of the crops. In order to evaluate the effect of supplemental irrigation on safflower fly (A. helianthi) population of safflower cultivars, an experiment conducted as a split plot based on randomized complete block design with three replications in field conditions. supplemental irrigation included four levels as follows: no irrigation (control) (I1), supplemental irrigation at budding stage (I2), supplemental irrigation at flowering stage (I3) and irrigation at seed filling stage (I4) as main plots and six cultivars including Padideh, Goldasht, Varamin 295, Zarghan 279, Mec.88 and Sina as sub plots. Results showed that with supplemental irrigation number of safflower fly (A.helianthi) decresed and no irrigation (control) treatment had the highest number of safflower flies with an average of 81.97±3.13 pests in the square meter. Amomg studied cultivars, Mec.88 with an average of 93.31±2.88 and Goldasht with an average of 45.89±6.63 had the highest and lowest flies in the square meter, respectively. The results of interactions between supplemental irrigation and cultivar showed that the highest number of safflower fly (A. helianthi) abtained from I2V5 treatment (no irrigation and Mec.88 cultivar). In general, the results showed that yield amount for Sina cultivar and supplemental irrigation at the flowering stage (I3V6) with an average of 2721±12.35 kg/ha was higher than other treatments.