Investigation of different irrigation times and nitrogen starter fertilizer on yield and water use efficiency of bean

Most bean cultivated lands are in areas that facing water deficit during the growing season. In order to investigate the effect of irrigation period and nitrogen fertilizer on yield, yield components and water use efficiency of red bean (cv. D-81083), an experiment was conducted as a split-plot based on a randomized complete block design with four replications at Boroujerd Agricultural Research Station (Lorestan) during two crop years. The main-plots were included four irrigation times after 36 (I1), 54 (I2), 72 (I3) and 90 (I4) mm of cumulative evaporation from class A evaporation pan and sub-plots were included the amounts and method of nitrogen fertilizer consumption including N1: without the use of nitrogen fertilizer (urea) or control, N2: consumption of 50 kg/ha of urea fertilizer at planting, and N3: consumption of 50 kg/ha of urea fertilizer at planting + 50 kg/ha of urea fertilizer at the beginning of the flowering stage. The results showed that, the highest number of pods per plant (18.3 pods), number of grains per pod (6.13 grains), grain yield (2538.8 kg/ha), biomass (5330.8 kg/ha) and water use efficiency (0.376 kg/m3) were achieved from I2N2 treatment. In the treatment of I4 application of nitrogen fertilizer didn’t have much effect on the traits. In general, the irrigation period can be planted from the beginning of sowing to before flowering stage every 7 to 8 days and after this period arranged for 5-6 days. Also, it is recommended to consumption of 50 kg/ha of nitrogen fertilizer at planting to stimulate early root growth until they sufficiently infected with rhizobium bacteria.