Study On Water Consumption Dynamics Of ’Hongyang’ Kiwifruit

The uneven temporal and spatial distribution of rainfall in Shuicheng County of Guizhou province resulted in the phenomenon of kiwifruit leaf and flower collapse in the germination and leaf-spreading stage and flowering and fruit-setting stage.In order to solve the problems of the kiwi fruit leaf and flower withering,achieve the goal of late mass production,study with shuicheng main planting fruit red Yang kiwi fruit as the research object,the determination of kiwi fruit seedlings under different moisture gradient change the water in the process of annual growth characteristics and growth,according to the characteristics of water consumption and water use efficiency（wue）to determine the suitable moisture gradient of kiwi fruit seedling growth;At the same time,the water consumption,growth changes and environmental factors of kiwifruit in the peak period were monitored,and the water consumption law,new point,leaf,fruit growth dynamic changes and environmental factors were analyzed.Finally,the optimal water gradient for kiwifruit growth was selected,and the water consumption of kiwifruit in different growth periods was obtained.The main achievements of the research are as follows:（1）There were significant differences in daily and monthly water consumption of kiwifruit seedlings under four different soil water conditions（normal irrigation,mild water shortage,moderate water shortage and severe water shortage）（P<0.05）,and water consumption gradually decreased with the decrease of soil water content.Under the conditions of different soil moisture content,all of them showed a normal"single peak type"and showed a"low-high-low"change mode.The diurnal variation range of water consumption of kiwifruit seedlings decreased with the decrease of soil water content.The peak time of daily and monthly water consumption of kiwifruit was different under different water conditions.When the soil water content is 75-90%of the field water capacity（normal irrigation）,kiwi seedlings maintain normal growth.The growth of kiwi seedling height,ground diameter and biomass decreased with the decrease of soil water content,indicating that water is an important factor restricting the growth of kiwi.（2）The water consumption of kiwifruit in peak period was different at different time scales.The average daily water consumption in different growth stages was as follows:the fruit expansion stage（3.02kg）>the fruit maturity stage（2.94kg）>the flowering and fruit-setting stage（0.99kg）>the bud and leaf development stage（0.77kg）.The change of daily water consumption showed a trend of"low-high-low".Kiwifruit water consumption mainly occurred between 8:00and 16:00,showing a"high in the day and low in the night",and there was a weak water consumption at night.The monthly water consumption of kiwifruit was as follows:July（90.60kg）>August（86.96kg）>June（66.20kg）>May（53.35kg）>April（41.21kg）>March（25.29kg）.The total water consumption in different growth stages was as follows:the fruit expansion（326.33kg）>the fruit maturity（88.13kg）>the flowering and fruit-setting（24.71kg）>the bud and leaf development（18.36kg）.There was no significant difference in the daily water consumption of kiwifruit per crown area at different growth stages,and the water consumption range was 0.420 kg·m^-2-0.509 kg·m^-2.There was no significant difference in the monthly water consumption of kiwifruit per crown area in different months,and the water consumption ranged from 6.73 kg·m^-2to 12.94 kg·m^-2.Kiwi yield per unit crown area is 2.81 kg·m^-2.（3）There were differences in the growth rate of each vegetative organ in different growth stages of kiwifruit.The new growth of kiwifruit mainly occurred from March 1 to April 15,during the germination and leaf-spreading stage and flowering and fruit-setting stage.Leaf growth mainly occurred from March 15 to May 15,during the leaf germination stage,flowering and fruit-setting stage and the early stage of fruit expansion stage.Leaf growth was the most rapid during the bud leaf development stage.Fruit growth occurred between April 15 and July 24,during germination and leaf expansion,flowering and fruit-setting,and fruit expansion.The fastest growth rate occurred at the early stage of fruit expansion.There was a significant positive correlation between SAP flow rate and growth change,and water consumption increased with growth rate increasing.（4）There was significant correlation between SAP flow rate and environmental factors at different growth stages.There was a significant positive correlation between SAP flow rate and solar radiation,air temperature,wind speed,soil temperature and soil moisture,and a significant negative correlation between SAP flow rate and relative humidity.Taking Rn,VPD,VT and Ts as independent variables and SAP flow rate as dependent variables,multiple regression analysis was conducted to obtain the fitting equation F=60.985+0.055Rn+11.844VPD+1.043VT-3.119Ts（R²=0.918）,The fitting equation F=-301.524+0.336Rn-77.366VPD+2.529VT+22.777Ts（R²=0.962）,The fitting equation F=643.830+0.124Rn+26.082VPD+1.683VT+29.093Ts（R²=0.968）,The fitting equation F=-1955.991-1.845Rn+175.061VPD+17.850VT+81.869Ts（R²=0.973）.Four environmental factors,including Rn,VPD,VT and Ts,could well explain the variation of SAP flow rate.（5）The diurnal variation of SAP flow was sunny>cloudy>rainy.Using Rn,VPD,VT and Ts as independent variables and SAP flow rate as dependent variables,multiple regression analysis was carried out.The fitting equation of sunny day conditions was F=-943.776+0.260Rn+49.647VPD+1.7558VT+42.698Ts（R²=0.956）,The fitting equation of cloudy day is F=-476.655+0.103Rn+63.639VPD+0.813VT+20.663Ts（R²=0.751）,The fitting equation of rainy day condition is F=-396.774+3.643Rn+228.831VPD+0.566 VT-1.854Ts（R²=0.674）;The fitting determination coefficient of sunny day,cloudy day and rainy day were 0.965,0.751 and 0.674,respectively.The fluctuation of environmental factors in rainy day was the largest and the fitting determination coefficient was the lowest.（6）Water consumption of kiwifruit was affected by environmental factors and growth characteristics,and there were differences in water consumption at different growth stages.According to the time and space distribution of rainfall,according to the unit water consumption the crown area of kiwi fruit set up a corresponding storage facilities,adjust the time and space distribution of rainfall,according to different phenological phase of kiwi irrigation water consumption proportion to needed for normal growth and soil water content,to ensure the health,high yield,high quality of kiwifruit.