Assessment Effect of Chitosan Foliar Application on Total Chlorophyll and Seed Yield of Wheat (Triticum aestivum L.) Under Water Stress Conditions

Abstract

Crop show morphological and physiological responses to microbial, physical or chemical factors which are known as elicitors. Chitosan is a natural biopolymer modified from chitin, which is the main structural component of squid pens, cell walls of some fungi and crab shells. Water stress is one of the most important abiotic stresses that affects plant physiological and morphological traits. In order to study the effects of chitosan foliar spraying on total chlorophyll, seed yield and its components of wheat under water stress conditions a split plot experiment based on randomized complete block design with three replications was conducted at Agricultural Research Center of Roudhen Islamic Azad University in 2017. The main plots included different irrigation regime at three levels (I₁: normal irrigation, I₂: water stress at heading stage, I₃: water stress in grain filing period) and chitosan foliar application at tillering and stem elongation stages by three concentrations (C₁:0, C₂: 0.05%, C₃: 0.1% chitosan in acetic acid is 1%) was belonged to sub plots. The results of analysis of variance showed that yield and its components in normal irrigation conditions have the best result and drought causes damage to the plant. The use of chitosan in the form of spraying had positive effects on some of the important characteristics of the wheat. Lowering the plant height, total chlorophyll, yield and yield components, as well as growth and development under drought stress conditions, are partially offset by the use of various concentrations of chitosan. The effect of chitosan on growth and yield of plant can be attributed to the production of plant hormones. The results of mean comparison showed that the highest economic yield was related to consumption of chitosan 0.1% in normal irrigation (6495.199 kg.ha^-1) and The largest reduction of economic yield was observed under water stress in seed filing stage and in the absence of chitosan application (1511.49 kg.ha^-1). The use of chitosan and normal irrigation has increased 76% to economic yield than control. It is concluded that foliar application of chitosan at vegetative stage enhanced the plant growth and development, which resulted from increased fruit yield in wheat. Among the concentrations, 0.1 percentages had superiority for plant growth, yield components and seed yield than the others. Finally its recommend that in the region under drought stress conditions, foliar application chitosan will be useful.