Unfortunately, there is relatively little direct experience with hardy kiwifruit production. The following information should, however, provide a good starting point for production of hardy kiwifruit as well as the fuzzy types. The water a vine loses through transpiration must be replaced by irrigation or rainfall. On a warm summer day in California, mature, full-canopy kiwifruit vines can transpire 7,000 to 8,000 gallons of water per acre per day. Transpiration occurs when leaves use carbon dioxide to produce carbohydrates through photosynthesis.
Irrigation is necessary to keep vines growing and productive and to maximize fruit size.
Severe drought also may cause fall flowering, which reduces the following year's production. Maturity of wood also seems to be delayed by drought, thus increasing risk of cold injury. However, too much water also may cause production problems. Judging vine water needs is difficult. At this point, it's not known whether irrigation requirements in Oregon differ from those in other regions.