Effects of Different Potassium Doses on Ion, Chlorophyll and Enzyme Contents of Drought Sensitive Bean Plants

Abstract

Droughts negatively influence plant production activities worldwide. Decreasing yields and quality exert financial problems on growers. This study was conducted to determine the effects different potassium doses on drought-induced yield and quality losses in beans. Drought sensitive Zulbiye bean cultivar and V71 bean genotype which was also identified as drought-sensitive in a previous study were used as the plant material. Bean seeds were sown in perlite-filled 2-liter pots. Potassium (K) doses were arranged as: 0 (control) ppm K, 500 ppm K, 1000 ppm K and 2000 ppm K. Experiments were conducted in randomized plots factorial experimental design with 4 replications with 4 pots in each replicate and 2 plants in each pot. Pots were irrigated with Hoagland nutrient solution throughout the growing season from sowing till harvest. Experiments were carried out in a climate chamber set at 22 - 25 degrees C day temperatures and 17 - 19 degrees C night temperatures. Irrigations were terminated in plants exposed to drought stress since the seedling period and irrigations were kept on in control plants. Experiments were terminated on 12th day of drought. Then, changes in catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (APX), malondialdehyde (MDA), chlorophyll a, chlorophyll b, total chlorophyll, K, Ca and Mg contents of the bean plants were investigated. It was observed that 1000 ppm and 2000 ppm potassium doses were quite effective in reducing drought-induced damages and decreases in drought sensitive Zulbiye cultivar and V71 genotype.