RESPONSE OF POTATO (Solanum tuberosum L.) TO WATER STRESS AT DIFFERENT GROWTH STAGES ON YIELD AND YIELD COMPONENTS AT SANKURA WEREDA, SILTE ZONE CENTRAL ETHIOPIA

Abstract

Water scarcity is one of the major challenges faced by the current agricultural systems worldwide, especially in arid and semi-arid areas. The objective of this study was to evaluate the response of potato (Solanum tuberosum L.) to water stress levels at different growth stages on yield and yield components under Sankura Wereda conditions. The field experiment was carried out in a randomized complete block design with four water stress levels and a total of thirteen treatments and three replications. The treatments were 100% ETc as a control and 85 ETc, 70 ETc, 55 ETc, and 40% ETc stress at each four growth stages of development stage of crop. Data on yield and yield components were collected and their responses to water stress were statistically tested using Analysis of variance (ANOVA)). The collected yield and growth parameters include plant height , leaf number, leaf area, leaf area index, tuber number, tuber diameter marketable yield , and total yiel. The results of the analysis of variance indicated that the different levels of water stress applied had a highly significant (p<0.01) effect on marketable tuber yield. The maximum marketable tuber yield of 41.52 tons/ha was achieved under full irrigation (100% ETc), and the minimum (32.86 tons/ha) was observed at 40% ETc at mid stage treatment. From the mean result of marketable tuber yield, it was observed that the control treatment (100% ETc) was significantly different from all treatments except the 85% ETc treatment water level. The highest water productivity (9.52 kg/m3 ) was observed under 40% ETc at mid stage. The water saved at 40% ETc and 55% ETc treatment resulted in 22.76% and 17.07% at mid stage, with yield reductions of 20.86% and 16.04, respectively. The marketable tuber yield obtained at 70% ETc was significantly higher than that obtained at 55% ETc and 40% ETc. From the result of the study, it was observed that the water stress levels on different growth stages when the water is a limitation ,70% ETc stress level give better result. Therefore, Irish potatoes could be irrigated at 70% ETc water stress level in limited water resource conditions.