EFFECTS OF IRRIGATION FREQUENCY AND WATER CUT-OFF IN DRIP TAPE IRRIGATION ON YIELD AND WATER USE EFFICIENCY IN POTATO CULTIVARS

摘要

Increasing demands for water and heightened awareness of the role of irrigatedrnagriculture in water quantity and quality protection mandate improved irrigation waterrnand nutrient management. This is particularly true for a high-value, water-sensitiverncrop like potato that requires large nitrogen fertilizer inputs. The objective of thisrnpaper are to evaluate the impacts of irrigation frequency and irrigation cutoff on yieldrnand water use efficiency (WUE) of potato cultivars, using drip-tape irrigation system.rnThis study was conducted during 2006-2008 years in Razavi Khorasan Agriculturalrnand Natural Resources Research Center (Iran). Experimental design was randomizedrncomplete blocks design (RCBD) in split split plot with three replications. Designrntreatments were include irrigation frequency (2, 4, and 6 day) in main plot, irrigationrncutoff (full irrigation, irrigation cut-off only in initial growth stage) in sub plot and potatorncultivars (Almera, Agria, Sante and Sinora) in sub-sub plot. Results showed thatrnirrigation frequency and irrigation cut-off had no significant effect on yield and WUE.rnThe effect of cultivar on yield and WUE was significant. Among cultivars, the mostrnyield and WUE was belonged to Agria. Three other cultivars (Almera, Sante andrnSinora) were in second level, thouth the yield of Almera was a little more that Santernand Sinora. In general regarding to treatments and its interaction effects on yield andrnWUE, it was concluded that the highest and the least yield and WUE were belongedrnto drip irrigation with 2 day irrigation frequency and without cut-off in Agria cultivar andrndrip irrigation with 6 day irrigation frequency and with water cut-off in Sinora cultivar,rnrespectively.