Mitigation the adverse effect of salinity stress on the performance of the tomato crop by exogenous application of chitosan

Background In recent years, ecofriendly compounds such as chitosan has been used to alleviate the destructive effects of salt stress. Chitosan is a natural biodegradable compound with no toxicity in nature and act as a stress tolerance inductor involved in physiological processes and prevent water loss through transpiration. Tomato cv. Rio Grande grown in pots was subjected with salinity stress in the form of 4 levels (0, 50, 100 and 150 mM) whose effect was mediated by treating it with different concentration of chitosan (0, 50, 100 and 150 mg L−1). Results The data revealed that various application of salinity had a negative effect on almost all the studied parameters. Tomato plants treated with distilled water having no salinity (control) recorded maximum plant height (cm), average number of compound leaves plant−1, leaf area (cm2), stem diameter (mm), number of fruits plant−1, fruit firmness (kg cm−2), leaf chlorophyll content (SPAD), fruit juice pH, yield plant−1 (kg) and minimum total soluble solids (Brix°). Whereas, minimum plant height (cm), average number of compound leaves plant−1, leaf area (cm2), stem diameter (mm), number of fruits plant−1, fruit firmness (kg cm−2), leaf chlorophyll content (SPAD), fruit juice pH, yield plant−1 (kg) and maximum total soluble solids (Brix°) were found in plants treated with salinity level of 150 mM. Chitosan concentration of 150 mg L−1 significantly mediated the effect of salinity stress and recorded maximum plant height (cm), average number of compound leaves plant−1, leaf area (cm2), stem diameter (mm), number of fruits plant−1, fruit firmness (kg cm−2), leaf chlorophyll content (SPAD), total soluble solids (Brix°) and yield plant−1 (kg) with minimum fruit juice pH. Conclusion It is concluded that foliar application of chitosan at the rate of 150 mg L−1 and salinity stress 150 mM could have positive impact on performance of tomato.