Role of Potash Fertilization in Reduction of Water Stress in Moonbean (Vigna radiata L.) and Yield Components

Abstract

The field study is conducted during two autumn seasons of 2012 and 2013 at Al-Anbar province to determine the actual water use by mungbean crop (Vigna radiata L.) under water stress conditions and potassium fertilizer, as well as the assessment of crop and growth characteristics. Four treatments of irrigation are used (I1 watering when %50 of available water used (treatment measure), I2 watering when %25 of treatment measure used, I3 watering when %50 of treatment measure used and I4 watering when %75 of treatment measure used) and three levels of potassium Sulfate fertilizer (41.5% K) (40, 80 and 120 kg. ha-1) in addition to the control (K0) are used, it is given K1, K2 and K3 to the potassium levels respectively. A split plot in randomized complete block design was used with three replications to do this experiment. Treatments of irrigation are used as main plots while potassium fertilizer levels are used as a sub-plot. Least significant difference (LSD) at 5% probability is used to compare the means. The treatment of I1 and I2 significantly gives the highest mean for yield and yield components without significant difference between them. I1 treatment gives the means( 35.26 and 33.83 pods. plant-1 ), the length of pod (7.49 and 7.41 cm), (7.35 and 6.62 seed. pod-1), 100-seed weight (4.07 and 3.78 gm), (1080.10 and 909.80 kg. ha-1) for the first and second seasons respectively, but I2 treatment has given the mean (34.09 and 32.64 pods. plant-1 ), (7.26 and 6.52 seed. pod-1), 100-seed weight (3.95 and 3.61 gm), (1047.10 and 881.60 kg. ha-1) for the first and second seasons respectively. Moreover K3 treatment significantly gives the highest means for yield and yield components (31.39 and 29.05 pods. plant-1 ),(6.88 and 6.04 seed. pod-1), 100-seed weight (4.03 and 3.67 gm), (895.30 and 743.10 kg. ha-1) for the first and second seasons respectively, The interaction among I1K3, I2K3 and I1K2 significantly gives the highest means for all plant characteristics without significant differences.