RESPONSE OF CERTAIN W'HEAT CULTIVARS TO ECOL0GICAL STRESSES IN RELATION TO QUANTITY AND QUALITY OF YIELD IN EGYPT

Abstract

This study aimed to guage the determental impact of weed interference on growth and productivity of wheat and to describe the time-course of wheat/weed competition. This is to elucidate the critical period of competition. Comparative study on competitive ability of Sakha 8 and Souhag 1 wheat cultivars to their neighbouring weeds was preformed in the Agricultural Experimental Farm of Ain Shams University located at Shalakan, Kalubia Governorate during the two successive growing seasons of 1992/93 and 1993/94.

Every trial consisted of twenty treatments which were the combination between the two wheat cultivars and ten treatments representing ten durations of weed interference treatments, i.e. associated weeds were left to interfere wheat plants from emergence to tillering; from emergence to booting; from emergence to milk ripe; during tillering stage; from booting to milk ripe; wheat was weed free from emergence to tillering; from emergence to booting; from emergence to milk ripe in addition to two control treatments namely weed interference with wheat plants throughout the growing season or wheat plant were kept weed-free throughout the growing season. The twenty treatments were arranged in split plot design in four replications where the varieties occupied the main plots and the interference stress of weed treatments were distributed at random in the subplots. Date of sowing was December 1st for the first season and November 18th for the second season.