Effect of foliar applications of methanol on growth and yield of sunflower (Helianthus annuus L.)

The effect of foliar applied methanol [Met] on growth and development of sunflower (Helianthus annus L.) plants, grown under controlled conditions or in the field, was studied. Foliar sprays of aqueous (30%, v/v) Met mere applied at the beginning of capitulum development (23 days from seedling emergence, DFE), and every 4 days up to 41 DFE, when the floret primordia were completely differentiated on the capitulum surface. Met treated plants grown under controlled conditions showed significant changes in vegetative growth and floral development. Met increased stem length by 23.6%, leaf area per plant by 66.5, stem dry weight by 51.4%, number of floret primordia by 46.5% and accelerated completion of floral development by 4.5 days. Met treated plants grown in the field did not show significant changes compared with controls, except subtle differences in vegetative development visually detected in leaf turgor and leaf color 5 days after the treatment commenced, but these changes were not statistically significant.