Orange Peel and Cauliflower Residues Supplementation Induce Morphological and Physiological Tolerance in Common Bean under Drought Stress

Drought is one of the most harmful abiotic stresses affecting the development and yield of the common bean (Phaseolus vulgaris L.). The current climate change and the resulting increased drought will worsen the negative impact of water stress on the plant. The powder of orange peel and cauliflower waste were added as soil supplementation at rates of 7 and 15 g/pot to pots of Phaseolus vulgaris L. under different drought conditions. The growth and physiological analysis were estimated after flowering period of common bean. In the pots where drought will be applied, irrigation was stopped for 2, 4, 6, 8 and 10 days during the flowering period and irrigation was performed again after water stress application. To measure moisture percentage of pots, first dry pots were weighed and after irrigation, their moisture variation in terms of percent was measured during stress from 2 to 10 days. The highest plant height was obtained from control. Leaf area decreased significantly despite the application of different powder, especially after 4 days of drought conditions. The highest root fresh and dry weight, raw ash were observed under control with the application of 7.5 g orange peel powder. Shoot dry weight decreased as the number of days exposed to drought increased, and the application of 15 g orange peel and cauliflower powder gave the highest results compared to control conditions. The highest dry matter was obtained from the application of 7.5 g and 15 cauliflower powder in the absence of drought. It has been revealed that as the duration of exposure to drought increases, the value decreases and plant powders are effective in increasing this value. Chlorophyll a, chlorophyll b and total chlorophyll values decreased significantly with drought, and the highest value was obtained from control conditions, followed by 15 cauliflower powder applications.