Herbicide tank-mixtures efficiency on weeds and wheat productivity

Abstract

Two field experiments were conducted at the Experimental Farm of the National Research Centre at Shalakan, Kalubia Governorate, Egypt during the 2005/2006 and 2006/2007 seasons to evaluate the response of two wheat cultivars (Gemmiza-9 and Giza-168) and associated weeds to numerous weed management treatments (metosulam, thifensulfuron, pyraflufen-ethyl, imazamethabenz, fenoxaprop, metosulam+imazamethabenz, metosulam+fenoxaprop, thifensulfuron+imazamethabenz, thifensulfuron+fenoxaprop, pyraflufenethyl+imazamethabenz, pyraflufen-ethyl+fenoxaprop, isoproturon, hand pulling once and weedy check. Results illustrated that all weeded treatments decreased dry weight of each weed group comparing to the unweeded one. Isoproturon came in the first order for controlling grassy and total weeds, but statistically leveled with those of metosulam+fenoxaprop and fenoxaprop alone for grassy weeds as well as metosulam+fenoxaprop, metosulam+imazamethabenz and thifensulfuron+fenoxaprop for total weeds. All herbicide mixtures resulted in synergistic interactions, where metosulam or thifensulfuron with fenoxaprop were the most synergized combinations. Dry weights of grassy, broad-leaved and total weeds were lower with Gemmiza-9 cultivar than Giza-168. The highest biological, straw and grain yields were achieved with application of metosulam+fenoxaprop. Gemmiza-9 was the potent cultivar for producing the maximal values of biological and straw yields ha.-1 , while grain yield was not affected by varietal differences. There were high negative and significant correlations between dry weight of total weeds with each of wheat plant height, SPAD value, spike length and weight, spikelets No./spike, grain weight/spike, 1000-grain weight, straw and grain yields. While, positive and high marked associations were recorded between grain yield with each other crop traits