The effects of biochar applications in different doses on nutrient uptake and some antioxidant enzyme of sugar beet plant growing under drought stress

This thesis study was conducted to determine the effects of different doses of biochar applications on the nutrient uptake and some antioxidant enzymes of sugar beet grown under drought stress. The study was carried out for two years in greenhouse conditions according to a randomized plot test pattern in three replications in 10 kg capacity pots. Biochar doses (BD) obtained from rosehip seed were applied as 0%, 0.5%, 1% and 2% (w/w), drought stress applications were applied as 100% (TK1), 75% (TK2) and 50% (TK3). The findings obtained showed that the shoot dry matter production was decreased with drought stress applications in both years. However, in drought stress, with biochar doses, shoot dry matter production increased in both years and was determined as 29.82 g pot-1 and 31.85 g pot-1 respectively. In the study, it was determined that tuber yield decreased with drought stress applications increased with biochar applications. In addition, biochar applications generally increased the macro and micro element concentrations of the plant. In the study, it was determined that the polar rations of sugar beet tubers increased with drought stress applications and decreased with biochar applications in both years. In the study, while the activities of the antioxidant enzymes catalase (CAT) and peroxidase (POD) increased in the first year with drought stress applications, it was determined that CAT, POD and ascorbate peroxidase (APX) enzyme activities generally decreased in the second year. While biochar applications decreased the antioxidant enzyme amounts of the plant under drought stress in the first year, POD and APX contents increased especially with 2% BD in TK1 and TK2 applications in the second year. In the study, chlorophyll a, chlorophyll b, total chlorophyll and carotenoid amounts decreased in two years with drought stress applications. On the other hand, biochar applications significantly increased chlorophyll a, chlorophyll b, total chlorophyll and carotenoids of sugar beet grown under drought stress, and 2% BD was the prominent. The research findings showed that the growth and development parameters of sugar beet plants such as yield, nutrient uptake, antioxidant enzymes increased significantly with biochar applications under drought conditions, which is a very important stress factor, and that biochar can be used as a breeding material in such conditions.