Post-synthetic modification of nano-chitosan using gibberellic acid: Foliar application on sorghum under salt stress conditions and estimation of biochemical parameters.

The challenge of desert farming with a high salt level has become an ecological task due to salt stress negatively affecting plant growth and reproduction. The current study deals with the cultivation of sorghum under salt stress conditions to counteract the effect of chitosan and gibberellic acid (GA). Here, the effects of chitosan, GA and nano-composite (GA@chitosan) on biochemical contents, growth and seed yield of sorghum under salinity stress conditions were studied. The results showed that spraying with GA@chitosan increased sorghum grain yield by 2.07, 1.81 and 1.64 fold higher than salinity stressed plants, chitosan treatment and GA treatment, respectively. Additionally, compared to the control of the same variety, the GA@chitosan spraying treatment improved the concentration of microelements in the grains of the Shandweel-1 and Dorado by 24.51% and 18.39%, respectively for each variety. Furthermore, spraying GA@chitosan on sorghum varieties increased the accumulation of the macroelements N, P, and K by 34.03%, 47.61%, and 8.67% higher than salt-stressed plants, respectively. On the other hand, the proline and glycinebetaine content in sorghum leaves sprayed with nano-composite were drop by 51.04% and 11.98% less than stressed plants, respectively. The results showed that, in Ras Sudr, the Shandweel-1 variety produced more grain per feddan than the Dorado variety. These findings suggest that GA@chitosan improves the chemical and biochemical components leading to a decrease in the negative effect of salt stress on the plant which reflects in the high-yield production of cultivated sorghum plants in salt conditions.