Altering the planting date and its effect on the phenology and yield of the three tropical legumes in the south of Kerman

The purpose of this research was to investigate the effects of the planting date from spring to winter on the phenological stages and the performance of three types of tropical legumes (local beans, cowpeas and mung beans). This study was performed as a factorial in a complete randomised block design with 3 replications for two years (2018-2019) in Agricultural Research Center in Jiroft, Kerman, Iran Experimental treatments included three planting dates of 30th Jan, 9th Feb and 19th Feb and three tropical legumes. The results indicated that legumes requirement 1200 degree-days of temperature growth during their developmental stages, considering the base temperature of 15˚C. The highest degree-days of growth from planting to germination, greening and from one to five leaves stage belonged to mung bean. the results showed that the cumulative temperature gradually decreased during the stages of flowering initiation, full flowering, pod initiation and grain filling in Mung beans and two types of beans. Mung bean seed yield stability on all three planting days averaged 0.7 t.ha-1, demonstrating the ability of this crop to adapt to temperature. The seed yield in local beans and cowpeas was the highest content averaged 2.3 and 4.6 t/ h in last cultivation on 19th Feb. Cultivation of legumes in early winter is therefore recommended as it has the opportunity to provide a cumulative temperature and growing day. It can reduce the negative effects on plant growth caused by intense heat and evaporation. High transpiration should be superior to spring patterns cultivation.