Effect Of Partial Root-Zone Drying On The Growth Of Grapevine And The Regulation Of Water Statue

As a new water-saving technology,PRD can improve the water use efficiency ,the taste and color and other fruit quality. By reducing the vegetative growth, it can also reduce the workload. In order to widely use ,there should be researches on the regulation methods for different crop and different cultivation conditions,such as wetting volume, irrigation low limit, alternate cycle,the best beginning and ending and optimal design of these above factors. In order to provide suitable irrigation water low limit and wetting volume for precision irrigation and fertilization under partial root-zone drying,in our research ,We studied the effect of partial root-zone drying to the vegetative growth,yield and quality of the fruits and water use efficiency. We also did some research on the most suitable water wetting volume,the low water limit of irrigation for the wet area and dry area and the roots growth and nutrient contents change.Our results showed: 1)Compared to the conventional irrigation,partial root-zone drying reduced the vegetative growth of the grape significantly:the shoot length and total leaf area are smaller than that of conventional irrigation. The fruit quality of PRD also changed abviously :the content of soluble solid and ratio of solid-acid ratio increased. The fruit matured ahead of time. The water use efficiency was significantly increased and the water amount decreased by about 50% compared to conventional irrigation.2)The research of the effect of the wetting volume under partial root-zone drying to the vine growth and development and water status of root zone showed that,the treatment with 27L wetting volume for every one shoot(per 0.7m2 leaf areas ) has no difference with double irrigation treatment which had the same wetting volume on water potential of wet zone, fruit yield and quality,but increased the water use efficiency. The results suggest that 27L wetting volume per shoot or 40Lwetting volume per square meter leaf areas can meet the requirement of the growth and development of 'vitis vinifera L 'grapevine under partial root-zone drying.3)In the mature stage,the fruit bulk and quality had no different with the conventional irrigation when the irrigation low limit was -15kpa and -30kpa in the wet area,while the limti was -15kpa,the soil water potential became lower ,even down to -80kpa. Considered of water-saving,yield maintaining and improving water use efficiency and other factors, the water irrigation low limit should be set at about -30kpa, that is 70% of soil saturated water content.4)The partial root-zone drying has strongly changed the structure of the root system and promoted the growth of the roots. The absorbtion of NO3-is higher than that of NH4+in the roots,while the absorbtion of tota nitrogen decrease. The content of K+both in roots and leaves are higher than CK,which will help to improve plant resistance, also contribute to the improvement of fruit quality.