Growth Response of Hararghie Coffee Accessions to Soil Moisture Stress at Seedling Stage at Jimma, South West Ethiopia

Abstract

Changes in climatic conditions and, thus, frequent occurrence of dry weathers are increasingly affecting coffee cultivation in Ethiopia through high seedling mortality, poor plant growth and development especially in drier coffee growing areas like Hararghie. However, very limited research has been conducted to identify the response of different coffee accession to water deficit in general and that of Hararghie genotypes in particular. This study was, therefore, conducted to determine growth responses of seedlings of fifteen Coffea arabica accessions collected from Hararghie areas. The experiment was conducted under a controlled condition in a rain shelter at Jimma Agricultural Research Center. Eight month old seedlings grown on potted nursery media were subjected to water deficit stress by withholding irrigation for 30 days followed by 21 days of re-watering.  It was laid down in a RCBD with three replications. Growth responses were assessed by measuring morphological characteristics and growth rates during the stress period and rate of recovery after re-watering. Beside, the rate of stress development was visually assessed by scoring the extent of wilting early in the morning and at noon hours every other day during the stress period. Analysis of variance for repeated measurements showed that there was a significant difference among genotypes for rate of stress development, rate of recovery, root to shoot ratio and leaf thickness. Among tested accession H-981 and H-857 showed significantly lesser extent of wilting at green house and higher rate of recovery after re-watering despite their lower total dry matter yield and root to shoot ratios, whereas as, lowest rate of recovery from the stress  was observed for accession H-915. Therefore, among the evaluated Hararghie coffee genotypes, accession H-981 and H-857 were found to be relatively tolerant to drought at seedling stage.

Keywords: Coffea arabica, Drought Tolerance, Hararghie, Morphological traits, Stress Score