Effects of Biochar and Chitosan on Morpho-Physiological, Biochemical and Yield Traits of Water-Stressed Tomato Plants

The application of biochar as an amendment can improve soil water retention, perhaps leading to higher crop yields. The experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during January to April 2022 to find out the effects of biochar and chitosan on physiological, and biochemical traits subjected to water stressed tomato plant. The treatments i.e. three water regimes i.e. i) Control (80% of field capacity) ii) 60% of field capacity (FC) and iii) 40% of field capacity (FC) and three drought mitigating agents i) chitosan (200 µL L−1 ha−1), ii) rice husk biochar (20 t/ha) and iii) biochar + chitosan were used in this experiment. Twenty five days old, healthy and uniform seedlings were transplanted in plastic pot using biochar. Ten days after transplanting drought was imposed up to flowering stage. Ten days after transplantation, chitosan was administered by hand sprayer. The results showed that water stress dramatically lowered tomato morphological, physiological, and biochemical characteristics except lowering sugar. However, biochar and chitosan significantly reduced the effects of water stress on tomato plants. The use of biochar and chitosan resulted in large improvements in plant height, number of leaves, chlorophyll content, fruits per plant, and yield per plant, vitamin C, and total soluble solid content; however, these treatments resulted in significant declines in lowering sugar content in stressed plants. Therefore, combined effect of chitosan and biochar had a greater impact on growth, yield and biochemical parameters.