Evaluation of sunflower cultivars to drought stress in different stages of phenology

Abstract

In order to evaluate sunflower cultivars under the effect of drought stress, an experiment was conducted on four cultivars in the form of a split plot in the form of a basic randomized complete block design in 3 replications at the khoy research station in 2024. Drought stress treatment was applied at four levels in the main plots, including: no water stress, stress during tillering, stress in the flowering stage, stress in the seed filling stage, and Master, Lacomka, and Euroflor and Azergol hybrids were arranged in the sub-plots. The results showed that the highest weight of 1000 seeds is from stress-free conditions (63.08 gr) and Lakomka cultivar (64.19 gr) and the lowest weight is related to stress conditions at the stage of head formation (51.22 gr) and Euroflor cultivar (51.52 gr). The highest seed yield of 3084 kg ha^-1 was related to no stress and the lowest yield was 1215 kg related to the treatment of stress in the head formation stage. Among the cultivars, Azargol yielded the highest yield of 2061kg and Master yielded the lowest yield with 1867 kg. Also, comparisons of the average mutual effects between cultivars and different levels of stress show that Azargol variety without applying stress with a yield of 3732 kg had the highest value and Master variety with applying stress in the forming stage obtained the lowest yield.