EFFECT OF RESIDUAL AND STRAW FOR THREE PRECEDING CROPS ON GROWTH, YIELD AND YIELD COMPONENTS OF WHEAT UNDER DIFFERENT NITROGEN FERTILIZER LEVELS

Two field experiments were conducted at Etay El-Baroud ExperimentalStation in El-Beheira Governorate, during 2013/2014 and 2014/2015 seasons,to investigate the effect of maize, soybean and sunflower as preceding crops
and their residual effects, as well as the effect of some straw treatments ongrowth yield and its components of wheat CV. Sakha 94) under three rates ofnitrogen fertilizer, i. e, 50, 70 and 90 kg/fed. The results of this investigation
could be summarized as follows:1-The results indicated that all studied characters of wheat were significantlyaffected by the preceding summer crops except, plant height, number ofspikes/m2, grain weight/spike and 1000 kernel weight which did not affectedby the preceding crops. The data showed that sunflower as a preceding cropleft good residual effect on wheat plant which gave the highest values for allstudied characters.2-With respect to straw treatments of the preceding summer crops, the resultsshowed that the differences between these treatments had significant effect
on each of number of spikes/plant, grain yield/plant; grains weight/m2 andgrain yield/fed. The date showed that hopping and scouring straw of thepreceding crop into soil did not improve yield and its components of wheatcompared to that of without chopping and scouring (control).3-Only each of grain yield/plant, grains weight/m2 and grain yield/fed. as well
as straw yield/fed. were significantly affected by nitrogen fertilizer levels, andwheat plant, gave the highest values of yield/plant, grains weight/m2 and grainyield/fed. when plants fertilized by 70 kg nitrogen /fed. while, straw yield
showed the highest value when wheat plants fertilizer by 90 kg nitrogen/fed..4-The results indicated that the interaction between preceding crops andstraw treatments had significant effect on each of number of spikes/plant,yield/m
 2, grain yield/plant and grain yield/fed., interaction between precedingcrops and fertilizer levels had significant effect, on grain yield/plant and grainyield/fed. on the other hand, the interaction between straw and fertilizer levels
showed significant effect on number of spikes/plant while, the interactionbetween preceding crops, straw treatments and nitrogen fertilizer levelsaffected significantly on 1000 kernel weight.