Physiological parameters, yield and seed quality of wheat as influenced by irrigation and split application of nitrogen

The experiment was conducted at the Agronomy field laboratory, University of Rajshahi, Bangladesh to study the effect of moisture stress and nitrogen split application on the physiological parameters,yield and seed quality of wheat. Four moisture treatments viz., control (I0), one irrigation at crown root initiation (CRI) stage (I1), two irrigations, at CRI and stem elongation stages(I2) and three irrigations, at CRI, stem elongation and flowering stages (I3); and four nitrogen treatments viz., control (N0), basal application (N1), ½ basal + ½ top dressed at 1st irrigation (N2) and 1/3 basal + 1/3 top dressed at 1st irrigation + 1/3 top dressed at 2nd irrigation (N3) were used. The experiment was laid out in split plot design with three replications by assigning irrigations in main plots and nitrogen in sub plots. Results showed that physiological parameters like TDM and LAI increased with the advancement of plant ages while CGR and NAR were slow at early growth stage and reached to maximum level at 50 to 65 DAS and then declined. TDM, CGR and LAI increased with the increase of number of irrigation. Three irrigations produced the highest TDM, CGR and LAI and the lowest values were found in control. The highest NAR was found in control at all sampling dates except 65 to 80 DAS. Growth parameters like TDM, CGR and LAI increased with the increase of splits of nitrogen application. Three splits of nitrogen showed the highest TDM, CGR, and LAI. The lowest values were found in control. With some exception the highest NAR was observed in control. Grain and straw yields were varied significantly due to irrigation levels. Grain and straw yields were increased with the increase of irrigation frequencies. The highest grain and straw yields were found in three irrigations and lowest values were found in control. Grain and straw yields were found to be significant in respect of nitrogen splits. Grain and straw yields were increased with the increase of nitrogen splits. Significantly the highest values were observed in three splits of nitrogen and lowest were in control. Irrigation had significant effect on all most all seed quality parameters. The highest germination (%), vigour index, nitrogen content (%) in grain and protein content (%) in grain were obtained in three irrigations. The lowest values were found in control. With some exceptions, significantly the highest germination (%), vigour index, nitrogen content (%) in grain and protein content (%) in grain were found in three splits of nitrogen and the lowest values were found in control. From the results it may be concluded that application of nitrogen in three equal splits at basal, crown root initiation and stem elongation stages and three times irrigation at crown initiation, stem elongation and flowering stages is better for maximizing yield and seed quality of wheat.