Bewässerungs- und Entwässerungssystemtechnik

Evaluation of Coffee Genotypes for Drought Tolerance in South Ethiopia

Abstract

Mulugeta Mohammed, Elias Meskelu and Tesfaye Shimbir

Drought is a major environmental constraint affecting the growth and production of coffee. Selection of drought tolerant Arabica coffee genotypes an important way to mitigate climate change impacts on coffee production. A Study was conducted at Awada research sub-center in Sidama zone of south Ethiopia(6045’ N, 380 38’E and 1740 m.a.s.l) with the objective to screen drought tolerant Sidamo coffee genotypes. The experiment was conducted during 2011/12 and 2013 under a controlled condition in a rain shelter; it was laid down in a RCBD with three replications. Fourteen Sidamo coffee genotypes were subjected to two watering regimes, water stressed and well watered for 28 days. The genotypes were also evaluated under field condition during 2014 season at Korkie sub-station which is located 20 km south of Awada (6034 N, 38039’E and 1800masl). Results of the experiment indicated that there was high significant difference among the genotypes for extent of wilting, total dry matter, relative leaf water content and leaf retention capacity. C85238 shows high drought stress resistance with 1.58 scale value while c9744 indicated as sensitive to drought stress with 2.99 scale value.c9722 obtained the highest value 11.76 gram in total dry matter, c85237 obtained the highest leaf retention capacity 51.28% and c85257 obtained the maximum relative leaf water content. Significant difference was also observed in root to shoot ratio and stomatal conductance with highest values obtained by c974 and c75227 respectively The field evaluation indicated that plant height, canopy diameter, coffee yield and number of primary branch were significantly influenced at P<0.01 and number of bearing branches and leaf turgid weight were influenced by the genotypes at P<0.05 with c9722 scored maximum value 288.9 cm plant height, 76 NBB, 163.43 cm CD and 11.76 qt/ha coffee yield. There was strong correlation observed between extent of wilting scored at seedling stage and grain yield at field condition of genotypes (r = -0.80). Therefore from all the three year evaluations c979, c974, c85238 c9722, c75277 and c1377 performed better in resisting drought under both field and controlled conditions.