تأثير الشد المائي على نمو و حاصل أربعة أصناف من حنطة الخبز Triticum aestivum L.

Abstract EN

Field studies were conducted during winter season of 2001 / 2002 and 2002 / 2003 At the Experimental Station of Agricultral Research Center , Ministry of science and Technology .

30 Km southern east of Bagdad , IRAQ .

the objectives of the study Were to test the effect of water stress during growth stages of wheat plant on some characters and grain yield of four wheat cultivars ,.

Asplit – plots design was used With three replications .the Irrigation treatments were : full Irrigation ( G0) as acontrol .

stress at Tillerng ( G1 ) Elongation ( G2 ) , Heading ( G3 ) , Flowering ( G4 ) and Grain filling ( G5 ) were as signed as amain plots .

in the full Irrigation ( G0 ) Irrigation was imposed at 2/3 Depletion of available water .

on the other hand in the stress irrigation treatment , the irrigation was imposed at 85 - 90% .

Depletion of available water according to growth stages .The sub plots were the wheat cultivars Abu-Graib 3 ,Tamoz 3, Aliz and Iraq .

The results show that the water stress in the vegetative stages (tillering , elongation and heading ) caused significant reduction in the number of days from planting to flowering by 1.9 6.3 and 5.8 days respectively while the water stress in the reproductive stage (flowering and grain filling ) caused significant reduction in number of days to maturity by 6 days .the water stress caused significant reduction in grain yield to all cultivars grain filling and elongation by 19 and 32 % respetively .stress treatment average grain yields of 6.06 ,5.18 ,4.88 ,5.26 ,5.49 , and 4.72 tonha for G0 ,G1 ,G2 ,G3 ,G4 and G5 respectively at is due to that water stress caused significant reduction in number of tillers ,plant hight ,flag leaf area , dry weight of stem , biological yield and yield components ,the value of that reduction depend upon the growth stages which imposed to water stress .