EFFECT OF SOWING DATES ON SONE ENDOGENOUS HORMONES, SHEDDING AND YIELD IN VICIA FABA PLANTS

Abstract

The role of endogenous auxin and abscislc &cid in regulating bud, flower and immature pod shedding in Vicla faba plants, and their influences on seed yield as affoctod by sowing dates, were investigated. Sowing two variotios of broad boan i.e. cv. Giza "2' and Giza '402' at tho end of October, achioved the lowest shedding percentage and consoquently increased seed yield percentage. On tho contrary, the early datn of planting (15th Octobor) showed significant increase of shedding percəntage and a decromont in seod yiold porcentage, comparing with the othor planting dates. At tho samo timo, tho apicee and the fully mature leaves extracts of the two varieties, which wore plantod at the end of October, detected remarkable increase in auxin levels at the three devolopmental growth stages under investigation, and the lowest level of abscisic acid at the period of pod shedding. It is obvious that the bost dato of sowing for less shedding percentage and high yield production in Vicia faba plants, was at the end of October In Delta regions.