PHYSIOLOGICAL ATTRIBUTES AND YIELD OF WHEAT AS INFLUENCED BY IRRIGATION AND NITROGEN FERTILIZER APPLICATION

Abstract

The experiment was conducted at the research farm and laboratory of Crop Physiology and Ecology Department, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh in 2014 - 2015 and 2015 - 2016 to study the morpho-physiological parameters, phenological stages, water relations, chlorophyll content, proline accumulation, nitrogen uptake, protein content, N use efficiency, yield and yield contributing characters of wheat. Benefit-cost ratio was calculated for cultivation of two varieties. Four levels of irrigations (i) I0- Rain-fed condition (control) (ii) I1- One irrigation (30 mm) (iii) I2- Two irrigations (30+30 =60 mm) and (iv) I3- Three irrigations (30+30+30 =90 mm) and four split application of nitrogen were (i) N0- control (no nitrogen) (ii) N1- total nitrogen at basal dose (iii) N2- one third of the N fertilizer was applied at basal dose, one third of the N fertilizer was applied at crown root initiation stage and the rest was applied at maximum tillering stage and (iv) N3- one fourth of the N fertilizer was applied at basal dose, one fourth of the N fertilizer was applied at crown root initiation stage, one forth was applied at maximum tillering stage and the rest was applied at heading stage. Two wheat varieties, namely, BARI Gom 24 and BARI Gom 26 were tested for the above mentioned parameters. The experiment was laid out in a split-split plot design with 3 replications. Irrigation and nitrogen treatments had significant effects on all above mentioned parameters in both the years. The plants grown in three irrigations (I3) condition needed the highest days for attaining their different phenological stages. Three irrigations exhibited the highest crop growth, morpho-physiological traits, water consumption, chlorophyll content, yield contributing characters, nitrogen uptake, grain and straw yield of wheat. With some exceptions, varieties had no significant effects on all the above mentioned parameters in this study. Among the nitrogen treatments, the highest crop growth, morpho-physiological traits, yield contributing characters, nitrogen uptake, protein content, N use efficiency, grain and straw yield were recorded in three split (N2) applications of nitrogen in both the years. Simple correlation coefficients between the yield contributing characters and grain yield for different irrigation and nitrogen treatments indicated that grain yield was positively correlated with yield components. In case of benefit-cost ratio, the highest benefit-cost ratio was found from BARI Gom 24 with three irrigations and three split applications of nitrogen. Wheat production with three irrigations gave the highest crop growth, morpho-physiological traits, water consumption, yield contributing characters, nitrogen uptake, grain and straw yield which were statistically similar with two irrigations. For the efficient use of nitrogen for wheat cultivation N fertilizer should be applied as three splits such as at basal, at CRI and during maximum tillering stages.