Effect Of Irrigation And Fertilizer Coupling On The Growth,Yield And Quality Of Trunk Bearing Apple In Southern Xinjiang Sandy Area

It is of great significance to study the effect of water and fertilizer coupling on physiological growth,yield,quality and water and fertilizer utilization efficiency of apple in order to improve the production efficiency of water and fertilizer and realize the improvement of agricultural quality and efficiency in the sandy area of southern Xinjiang.In this study,the main fruit-bearing apple trees in the sandy area of southern Xinjiang were taken as the research object,and the relevant field experiments were designed according to the principle of quadratic regression general rotary combination design.The effects of water and fertilizer coupling on the physiological growth,yield,quality and water and fertilizer utilization efficiency of trunk bearing apple trees in the sandy area of southern Xinjiang were systematically studied.The main conclusions are as follows:(1)The growth model of new shoot length,new shoot stem diameter,leaf area index and fruit volume of trunk fruiting apple in sandy area of southern Xinjiang unde’r the coupling effect of water and fertilizer was constructed,which well described the growth trend of related growth indexes during the growth period.Among them,the maximum growth rate of shoot length was 0.35-0.69 cmld,and the maximum growth rate of fruit volume was 4.21-6.81 d/cm3.(2)A quadratic regression model was constructed with net photosynthetic rate,SPAD value and other related physiological indexes as response variables.The single factor effect an d interaction effect of water and fertilizer on photosynthesis,SPAD value and other related physiological indexes of main fruit-bearing apple in southern Xinjiang were analyzed,and the optimal water and fertilizer dosage with net photosynthetic rate and SPAD value as the control target was proposed.(3)The responses of water consumption,water consumption intensity and water consumption modulus of apple trees at different growth stages under the coupling of water and fertilizer were quantified.The average water consumption in each growth period was 27.8 mm,77.9 mm,400.5 mm and 136.2 mm,respectively.The water consumption modulus at different growth stages were 3.49%-5.26%at flowering and fruit setting stage,and 10.94%-13.9%at young fruit development stage.The fruit enlargement period was 58.97%-66.71%;the fruit ripening period was 17.64%-24.3%.The water consumption modulus of fruit enlargement period is the largest,which is the key period affecting fruit growth and development,yield and quality formation.(4)The quadratic regression model with yield as the response variable was constructed,and the single factor effect and interaction effect of water and fertilizer on the yield of main fruit type apple in the southern Xinjiang sandy area were analyzed.The range of irrigation amount and fertilizer application amount(irrigation amount 587.35-641.05 mm,nitrogen application amount 121.37-129.85 kg/hm2,potassium application amount 227.75-250.88 kg/hm2,zinc application amount 11.55-13.62 kg/hm2)under the yield of more than 35000 kg/hm2 was proposed.(5)Taking yield,water and fertilizer use efficiency and quality as evaluation indexes,using analytic hierarchy process,entropy weight method,game theory combination weighting method and grey correlation analysis method,the evaluation system of water and fertilizer coupling effect of main fruit type apple in southern Xinjiang sandy area was constructed.The quadratic regression model was established by taking the combined evaluation value of water and fertilizer coupling effect as the response variable,and the range of irrigation amount and fertilizer application amount(irrigation amount 555.85-617.05 mm,nitrogen application amount 118.08126.81 kg/hm2,potassium application amount 220.64-242.42 kg/hm2,zinc application amount 11.30-13.35 kg/hm2)was proposed under the comprehensive consideration of yield,water and fertilizer utilization efficiency and quality.