EFFECT OF IRRIGATION SCHEDULING ON YIELD, QUALITY AND FUNCTIONAL PROPERTIES OF POTATO TUBERS

Potato growth, yield, and quality are important parameters under scheduling of surface irrigation using gated pipes to evaluate water management in Nile valley soils. A field experiment was conducted during 18 Jun.-20 May 2015 spring growing season using potato (Solanum tuberosum) grown in northern Egypt at Qusina, Minoufia, Egypt to study potato response, quality and functional properties to different irrigation scheduling levels. A Randomized Split-Plot Design with irrigation scheduling treatments as irrigation levels 75, 60 and 45% from available water and water cutoff times when water flow was reached the field end (after 5 min, exactly reached and before 5 m) were randomly distributed. Non-uniformity of irrigation applications were evaluated along irrigation furrow as dependent variables measured at the (0–20), (20–40) and (40–60) m along 60 m irrigation line. Potato tuber yield and quality were significantly affected by irrigation levels (IL), water cutoff time (WCT) and distance from upstream end (D). Tuber yield, water use efficiency, dry matter percentage, percentage of tuber size grade and yield of chips were significantly affected by IL, WCT and D, and their interaction IL*WCT; WCT*D; IL*D and IL*WCT*D except percentage of tuber size which was non-significantly affected at medium size by (WCT) and large size by interaction IL*WCT*D. The highest tuber yield was under treatment irrigation level of 75% from AW and when water flow was exactly reached the field end. Improving quality and saving water were under both irrigation level of 45% AW and water cutoff before reaching 5 m from downstream end.