Identification of Critical Growth Stage for Export Type Common Bean (Phaseolus Vulgaris L.) to Moisture Stress

Abstract

A study was conducted on the identification of critical growth stages to moisture stress of common bean, cultivar Chercher, at nine different growth stages[emergence of cotyledons (V1), development of primary leaves (V2), development of first trifoliate leaves (V3), development of third trifoliate leaves (V4), bud formation (R5), flowering (R6), pod formation (R7), pod filling (R8) and maturity (R9)] with irrigating at those different stages were made at Haramaya University Research site, Haramaya, during 2010 and 2011. The identification of sensitive growth stages to at different growth stages on the yield and yield components of common bean were determined. The effect of water stress showed significance effect on most parameters considered. But, water stress on the days of flowering and dry biomass was not showed significance difference. However, applying the water deficit at vegetative growth stages (V1 to V4) did not significantly affect the yield and yield components of common bean as compared to the reproductive growth stages (R5 to R9). The highest yield per plant (6.19 g) and lowest yield per plant (1.55 g) were recorded when irrigation was withheld at the development of cotyledon (V1) and at bud formation (R5) growth stages. As compared to the well watered control, the lowest (3%) and highest (76%) seed yield reductions were obtained when water deficit was imposed at V1 and R5 stages. As this finding it is concluded that the most critical growth stage of common bean, Chercher variety to water deficit is at bud formation (R5).