Response of Safflower in Water Deficit and Foliar Application of Putrescine and24-Epibrassinolide

safflower is an oilseed plant tolerant to water deficit, and have an important role in oil production, dyeing and cosmetics industry. This research was carried to evaluation response of safflower in water deficit and foliar application of putrescine and 24-epibrassinolide in the Research Farm, Faculty of Agriculture, and University of Tabriz.

This research was carried out in 2019 as split plot based on randomized complete block design with three replications at the Research Farm, Faculty of Agriculture, University of Tabriz, to investigate the responses of safflower to different levels of irrigation (I1, I2, I3, I4: Irrigation after 70, 100, 130 and 160 mm evaporation from class A pan) and foliar sprays of water (control), putrescine, (60 µg/l) and 24-epibrassinolide (25 µg/l). All plots were irrigated regularly until seedling establishment and thereafter irrigation intervals were applied according to the treatments. Foliar spays were undertaken slightly before flowering.

Chlorophyll content index, relative water content, leaf per plant, plant height, green cover percentage and grain yield were decreased, but leaf temperature was increased significantly under moderate and severe water limitations. Foliar sprays of growth regulators improved all these traits under different levels of water supply.

Application of putrescine and 24-epibrassinolide at the end of vegetative growth at one stage under water stress conditions had a significant effect on safflower property and increased seed yield in all irrigation treatments, especially in normal irrigation. Application putrescine and brassinolide in water deficit conditions can be produce a suitable yield.