Investigation on morphological characteristics, grain and oil yields of castor bean at different plant densities and irrigation intervals

Because of importance of castor bean oil in different industries and limited water resources in many parts of Iran, an experiment was conducted to determine the effect of irrigation intervals and plant densities on grain, oil yield and yield components of castor bean, at Experimental Station, College of Agriculture, Ferdowsi University of Mashhad. Four irrigation intervals (one, two, three and four weeks) and four plant densities (1, 2, 3 and 4 plants per square meter) were compared in a split arrangement based on completely randomized block design with four replications. The plant characteristics were studied in terms of plant height, inflorescence height, the first inflorescence height from soil surface, inflorescence number, branch number, number of capsule per plant, number of grain per plant, biomass per plant, 1000 grains weight, grain yield, harvest index and oil yield. Result showed that the effect of different irrigation intervals was significant on all of characteristics under study except harvest index and oil percentage