Can methanol foliar application improve the productive performance of sunflower under water deficit stress

Abstract

In order to investigate the effect of water deficit stress and methanol foliar application on yield and yield components of sunflower (Helianthus annuus L), an experiment was conducted in the split plot form based on Completely Randomized Block Design with three replications during growing seasons of 2011-2012. Treatments were water deficit stress in four levels: a1: severe stress (25% FC irrigation), a2: mild stress (50% FC irrigation), a3: fair stress (75% FC irrigation) and a4: normal irrigation (100% FC irrigation) and the foliar application of methanol in six levels [b1:0, b2:7, b3:14, b4:21, b5:28 and b6:35 (v/v)]. The analysis of variance showed significant effect of interaction between water deficit stress and methanol foliar application on plant height, stem and head diameter, empty and full seed number (p<0.01). The results showed that foliar application with 21% (v/v) methanol and normal irrigation produced 35% more plant height, 65% more head diameter. Besides, the results also proved that 14% (v/v) methanol foliar application in normal irrigation had the highest stem diameter (34 cm).furthermore, the lowest empty seed number (248) and the highest full seed number (1611) were observed for 7% (v/v) methanol and normal irrigation.