Back to Contents

FREE FULL TEXT PDF

IRRIGATION AND NITROGEN EFFECTS ON GRAIN DEVELOPMENT AND YIELD IN WHEAT (TRITICUM AESTIVUM L.)

EJAZ AHMAD WARAICH^*, R. AHMAD^*, ANSER ALI^** AND SAIF ULLAH^***

Abstract: A field study was conducted to determine the effects of different levels of irrigation and nitrogen on grain development (grain filling rate and grain filling duration) and grain yield of wheat (Triticum aestivum L.) variety Inqlab-91. The experiment was conducted at the Crop Physiology research area, University of Agriculture, Faisalabad, Pakistan, during the year 2002-03 and 2003-04. Four irrigation levels i,e one irrigation ( Irrigation at tillering stage), two irrigations ( irrigations at tillering and anthesis stages), three irrigations (irrigations at tillering, anthesis and grain development  stages), four irrigations (irrigations at tillering, stem elongation, anthesis and  grain development stages) and four nitrogen levels i.e, 0, 50, 100 and 150 kg N ha^-1 were tested in this study. Grain yield and all primary yield components increased linearly in response to irrigation and nitrogen in both seasons. Grain yield, number of spikes m^-2, grains spike^-1 and grain weight responses were greater at the higher N rates. Mean grain yield in four, three and two irrigation treatments compared with that in one irrigation treatment increased by 47, 23 and 9% during 2002-03 and 91, 84 and 23% in 2003-04, respectively. Water deficit reduced spikes m^-2.  In both years, the average reductions in spikes m^-2 and grains spike^-1 in one irrigation treatment at all N levels were 24% and 36%, respectively. Decreasing number of irrigation accelerated the GFR and hastened the GFD, whereas N application increased GFR and duration at all irrigation levels. Reduction in grain yield under less irrigation treatment is the result of a significant reduction in number of effective tillers and nitrogen supply improved effective tillers per unit area at all irrigation levels.

^*Departments of Crop Physiology ^**Agronomy and ^***Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan
Corresponding author. E-mail: uaf_ewarraich@yahoo.com