Haricot Bean agroecology in Ethiopia: definition using groclimatic and crop growth simulation models

Abstract

Bean (Plraseolus vulgaris L.) i~ an important food and cash crop grown in diverse environmental settings in Ethiopia. Its proouction is very heterogenous in terms oi ecology, cropping system and yield. This study analyses!he agroclimatic re5tlurces of 18 representative bean growing sites in Ethiopia and asseSsts the potential yield snd moisture delicit stress ming DRYBEAN (DSSAT V.3) growlo modelo Annual rainfaD oharious localions ranged rroro 580 mm (Mekele) lo 1995 mm (Gure). Seasonal rainralI varied rrom 270 mm (Babile) lo 1650 mm (Gore). Toe lengtb oflbe growing i>eriod is rrom onIy SOday. (MekeIe) lo more iban 220 days (Jimma). Among the agrodimatic variables, annual rainran, seasonal rainfall, Jengtb ofthe growing period and a!utude (temperature) are important factors to cluster the bean growing regions iDto 3 majar and 6 minar homogeneous groups in agronomic sense for strategic planmng. Simuiated yield potential varied from 1,6 ! ba (Jijiga) to 3.3 t ha rnako), Planting dale has a significan! impac! on simulated yicld in tbe sub .. humid and senlI~arid clusters. Yield losses for each day of delayed planting alter the efTedive ooset of rainfaU reached up lo 60 kg ha'l day-l. Moisture deficit stress was found to be an important limiting factor in !he semi-arid and moderately limiting in fue sub~bumid regions. The analysis estabUsbed that bean improvement work sbould focus on the development ofhigh-yielding, long*ntaturing genotypes for multiple cropping systems in the humid regions. In the s:emi~arid regions empbasis shouJd be Oh thedevelopment of drought tolerant and early maturing cultivars which lit well with efficientsoil and water conservation practices.