M.A. Thesis:

Morphophysiological response of cotton to amount and consumption application of nitrogen in saline conditions

There is a lack of sufficient information on cotton responses to nitrogen amount and application method in saline soil, the objective of this study was to investigate the effects of nitrogen (N) rate and application method on yield and yield components of cotton under saline field condition. A split plot design based on randomized complete block design with three replications was conducted in Sabzevar Agriculture and Natural Resources Research center in 2015. Factors were: N rate (150 and 225 kg ha-1 as urea form (46% N) as the main plot and application method (50 at planting+25% at first weeding and 25 at second weeding (50P+25W1+25W2), 25 at planting+25% at first weeding, 25% at second weeding and once foliar application (‰5) at flowering stage (25P+25W1+25W2+25S), 25 at planting+25% at first weeding and once foliar application (‰5) at flowering stage (25P+25W1+25S), 25 at planting+25% at first weeding, 25% at second weeding and two times foliar application (‰5) at flowering and bolling stage (25P+25W1+25W2+25SFB) and 25 at planting+25% at first weeding and two times foliar application (‰5) at flowering and bolling stage (25P+25W1+25SFB) as the sub plot. Increasing of N level to 225 kg N ha-1 increased chlorophyll index, plant height, monopodial and sympodial branch number, boll number, boll weight and seed cotton yield. Lint percent, Lint yield and seed per boll was not affected by N rate. The highest plant height and seed per boll was obtained at N application as 25P+25W1+once foliar application at flowering. 25P+25W1+25W2+25SFB had the highest boll weight, seed cotton per boll, seed cotton yield, lint percent and lint yield . The results obtained here suggest that 225 kg Nha-1 application (as urea form) as 25 at planting+25% at first weeding, 25% at second weeding and two times foliar application (‰5) at flowering and bolling stage can improve the seed cotton yield grown under saline condition. Key words: Application method, Cotton yield, Nitrogen rate, Salinity stress

Keywords: Application method, Cotton yield, Nitrogen rate, Salinity stress