Effect of various nutritional systems on growth characteristics, sepals yield and yield components of sour tea (Hibiscus sabdariffa L.) under drought stress

Water deficit stress is a major environmental limiting factor of plant growth and crop productivity. Therefore, many studies have been done to minimize the stress effects caused by Water deficit in agriculture and plant physiology. In present investigation, to study the effects of nano and nano bio-fertilizers on reducing the damage caused by drought on growth parameters on roselle an experiment was conducted at the experimental farm, University of Zabol, in split plot based on randomized complete block design with three replications, during 2015. Four drought stress levels 30, 50, 70 and 90 percent of available water were considered as main plots and four levels of fertilizers nano-iron, nano-ZFM, nano-biomik and control (lack of fertilizer) were considered as sub plots. The studied traits included plant height, fresh and dry weight of vegetative and roots, number of lateral branches, number of calyx, fresh and dry weight of sepals. Main effects of fertilizer, drought stress and their interaction were significant for all studied traits in 1 percent probability level. Maximum of fresh and dry weight of sepals, number of calyx, number of lateral branches, fresh and dry weight of vegetative and plant height were obtained under treatment of 70 percent of available water and foliar application of nano-iron. The highest amount of fresh and dry weight of roots belonged to 70 percent of available water and foliar application of nano-ZFM. Spraying with nano-iron mitigated the effects of drought stress and increased the quantity of roselle sepals.