Effect Of Continuous Negative Water Pressure Supply On Growth, Development,and Physiological Mechanism Of Eggplant

Negative water pressure supply device was adopted in this study,and the aim of exploring the negative water pressure supply effect of on the growth,development,physiological property,nutrient uptake,yield and quality of eggplant is to determine the optimal negative water pressure supply suitable for eggplant growth,which provides theoretical basis for water management of eggplant.In the greenhouse using pot experiment,investigate the three different water supply pressures(-3 k Pa、-8 k Pa、-15 k Pa)and irrigation(CK)four treatments on total water consumption,yield,water use efficiency,different growth stages agronomic trait,dry matter accumulation,nitrate reductase activity,root activity,eggplant fruit quality,eggplant nutrient accumulation,soil available nutrient content,soil enzyme activity and other indicators.The results are as follows:(1)The water pressure supply was controlled in the range of-3 k Pa to-15 k Pa,and compared with the CK treatment,the total water consumption of eggplant decreased by 20.51%~70.00%,the total water consumption intensity decreased by 22.18%~70.27%,and the water use efficiency increased by 7.45%~41.48%;When the water supply pressure was controlled at-3 k Pa,compared with the CK treatment,the nitrate reductase activity,root activity and chlorophyll content from the early flowering stage to late growth stage increased by 6.14%~15.5%,11.11%~33.33% and 20.04%~51.58%,respectively;the yield of eggplant increased by 12.43% compared with CK;the soluble sugar,soluble protein,and vitamin C content of eggplant fruits at different maturation increased by 14.47%~47.22%,16.33%~58.78%,and 19.64%~43.42%,respectively,when compared with the CK treatment.When the water pressure supply was controlled at-3 k Pa,it can improve water use efficiency,promote growth and development,improve physiological activity,increase yield,and improve the quality of eggplant.(2)When the water pressure supply was controlled in the range of-3 k Pa to-15 k Pa,the dry matter accumulation and nitrogen,phosphorus,and potassium nutrient accumulation of eggplant organs decreased with the decrease of water supply pressure.At the late growth stage,when the water supply pressure was controlled at-3 k Pa,compared with the CK treatment,stem organ dry matter accumulation increased by 17.42%,fruit dry matter accumulation increased by 8.06%,accumulation of nitrogen,phosphorus and potassium increased by 30.37%、36.93% and 23.65%,respectively;there was a quadratic parabolic relationship between water consumption and yield,water use efficiency of eggplant,and when the total water consumption was 59.57 L/plant,the yield reaches a maximum was 1479.86 g/plant,and water use efficiency reaches a maximum was 24.85 g /L.Under the condition of this experiment that the negative water pressure supply was controlled at-3 k Pa contribute to the nutrient absorption and utilization of eggplant,achieving the effects of water conservation and high efficiency.(3)When the water supply pressure was controlled at-3 k Pa,compared with the CK treatment,the alkali hydrolysable nitrogen,available phosphorus and available potassium content of soil from the early flowering stage to late growth stage increased by 11.03%~21.98%、14.90%~23.98% and 6.48%~13.32%,respectively;the urease activity of soil increased by 11.06%~19.89%,the phosphatase activity increased by 9.11%~17.07%,and the sucrose activity increased by 3.73%~13.16%.At the Early fruit bearing stage,the catalase activity increased by 5.19%,when compared with the CK treatment.Under the negative water pressure supply that there was extremely significant positive correlation between urease,phosphatase,sucrose,catalase activity of soil and alkali hydrolysable nitrogen,available phosphorus,available potassium content of soil,indicating that there was a general relationship between nutrient and enzyme activity of soil.(4)Under the negative water pressure supply that there was significant positive correlation or extremely significant positive correlation of general relationship between nitrogen,phosphorus and potassium content of eggplant stem,leaf,fruit and soil alkali hydrolysable nitrogen,available phosphorus,available potassium content,soil nutrient contents can significantly affect the absorption and utilization of nutrients by eggplant.