Responses of Seed Yield and Morphophysiological Traits of Mungbean (Vigna radiate L.) cv. Gohar to GDD and Plant Density in Ilam Region

To study the effect of GDD and plant spacing on some agronomic, morpho-physiologic traits and qualitative traits of mungbean (Vigna radiate L.), cv. Gohar, a field experiment was conducted by using a factorial experiment based on a randomized complete block design with three replications in summer of 2016 in Ilam region. The first factor, planting date, consisted of three GDD of 1910 GDD, 1740 GDD and 1485 GDD (planting dates of 10 and 25 July and 5 July) and the second factor plant spacings on the row consisting of four levels (5, 10, 15 and 20 cm) with 50 cm between rows (40, 20, 13.3 and 10 plants.m-2,respectively). The results showed that leaf chlorophyll content, leaf area, relative water content, pods.plant-1, pods.m-2, grain yield, biological yield and harvest index were affected by planting date× plant distances on the row. The highest chlorophyll content (1.85 mg/g fresh weight), pods.plant-1 (44 pods), pods.m-2 (507 pods), grain yield (3149 kg.ha-1) and harvest index (50.2%) were obtained at 1740 GDD and 15 cm plant distances on the row. According to the results of this experiment, the highest grain yield and yield components belonged to the planting date of 1740 GDD (planting dates of 25 July) with 15 cm plant distances on the row (13.3 plants.m-2) in Ilam region.