Optimization of chitosan level to alleviate the drastic effects of heat stress in cucumber (Cucumis sativus L.)

Mujahid Ali, Chaudhary Muhammad Ayyub, Zahoor Hussain, Rashid Hussain and Shahla Rashid

ABSTRACT    Heat stress is a major concern during cucumber production. To explore its production potential, chitosan could play a vital role in alleviation of heat stress. This study was planned to evaluate the potential of chitosan in cucumber growth where it is more effective under high temperature with two factorial under Completely Randomized Design (CRD). Four genotypes were previously screened out; two were tolerant (L3466, Desi-cucumber) and two were sensitive (Suyo Long and Poinsett). These genotypes were grown in the growth room having a normal temperature (28°C/22°C day/night). One day before heat treatment (40 ºC/32 ºC day/night), chitosan foliar spray with different concentrations (0, 50, 100, 150, 200, 250, 300 ppm) was applied. It was found that 200 ppm of chitosan level revealed significantly better results on growth index (seedling length of shoot and root, the mass of fresh and dry seedlings and the number of leaves per seedling) and physiological index (chlorophyll contents and electrolyte leakage). It was also found that heat sensitive genotype Suyo Long gave the maximum seedling electrolyte leakage (74.03%) followed by Poinsett (69.35%) at control (0 ppm chitosan). The lowest seedling electrolyte leakage (28.85%) was noted in Desi-cucumber followed by L3466 (30.16%) with foliar application of 200 ppm of chitosan. So, chitosan spray at 200 ppm explored the maximum potential to alleviate the effect of heat stress in cucumber genotypes. © 2020 Department of Agricultural Sciences, AIOU

Keywords: Abiotic stress, Chitosan, Cucumber, Heat stress, Optimization

Permanent link to this article: https://jpaa.aiou.edu.pk/?p=872