Response Of Quality And Yield Of Greenhouse Tomato With Drip Irrigation Under Film To Planting Row Spacing And Irrigation Amount

Tomato is one of the main protected cultivation vegetable in northern China.Most tomatoes in greenhouses in Northwest China adopt ridge and furrow planting mode,so the planting distance and plant spacing of tomato plants directly determine the planting density.A reasonable planting distance and plant spacing of tomato not only can improve the ventilation and light conditions,so as to lay the foundation for high quality and yield of crops,but also can get Better land use efficiency.However,in the actual production process,the large row spacing(ridge distance)and plant spacing in the greenhouse in the Northwest China are relatively fixed,while the small row spacing(planting row spacing)and irrigation volume setting are subjective,thus restricting the increase in yield and quality of greenhouse tomatoes in the region.Studying a reasonable combination of planting row spacing and irrigation volume has a great significance to the further development of greenhouse tomato industry in the region.The experiment was conducted in the greenhouse field in January 2016,the ridge distance is 80 cm,planting spacing is 35 cm.The treatments comprised three planting row spacing(L1(60 cm),L2(45 cm),L3(30 cm)),and based on the cumulative evaporation from a 20 cm diameter pan between two irrigations(E),0.6 E,0.8 E,1.0 E,1.2 E were set as four different levels of irrigation amount,studying the effects of different planting row spacing and irrigation volume combination of drip irrigation on the indexes of tomato in solar greenhouse.The main conclusions were as follows:(1)The effect of planting spacing on plant height,stem diameter,and leaf area index reached significant levels,and the effect of irrigation volume on the plant height and leaf area index reached a significant level,but the impact on stem diameter only reached a significant level from the mid-term of phenophase,it shows that the response of stem diameter to irrigation volume is less sensitive.The interaction between planting spacing and irrigation volume had no significant effect on stem diameter and leaf area index,and the effect on plant height only reached a significant level from the mid-term of phenophase.Treatments with a lower row spacing result in higher leaf area index and plant height and the lowest stem diameter,indicating that it is prone to cause spindling.(2)As the growing period progresses,the cumulative effect of water stress becomes more and more obvious and it begins to have a significant inhibitory effect on photosynthetic physiological activity.The effect of planting row spacing and irrigation amount on the net photosynthetic rate reached a significant level,but the interaction between the two had no significant effect on the net photosynthetic rate and each fluorescence parameter.Excessive and insufficient irrigation will inhibit the photosynthetic physiological activity of tomato plants;the shading and low light conditions formed by overly high planting density can easily lead to the decline of photosynthetic capacity and affect the normal growth of plants.(3)The quality indicators of tomato were significantly affected by planting spacing and irrigation volume,and only the ratio of sugar to acid was not significantly affected by the amount of irrigation water.However,the interaction between plant spacing and irrigation volume only had a significant effect on soluble solids,VC,and lycopene.Excessive irrigation results in a decrease in the fruit shape index and an increase in the transverse diameter variation coefficient,resulted in a decrease in the appearance quality of the tomato fruit.Excessively high or low irrigation results in a decrease in VC,lycopene,and soluble solids,affecting the nutritional quality of tomato.The results of the improved fuzzy grey relational method and CRITIC method have little difference with the results of tomato comprehensive quality evaluation,that the L2-0.8E treatment had the best comprehensive quality of tomato,and the L1-1.2E treatment was the worst,in the case of the same amount of irrigation water,the treatment ranks of each planting row spacing is L2>L3>L1.The regression analysis of planting row spacing,irrigation volume,and integrated quality of tomato indicated that high or low planting row spacing and irrigation volume would cause the decline of the comprehensive quality of tomato.(4)The effect of plant spacing and irrigation volume on yield and irrigation water use efficiency reached extremely significant levels,but there was no interaction between the two.Under the same planting row spacing,the yield of tomato gradually increased with the increase of irrigation volume and the irrigation water use efficiency gradually decreased;With the same amount of irrigation water,the yield of tomato and the efficiency of irrigation water use decreased with the decrease of planting row distance.(5)Among tomato growth physiology indexes,only leaf area index and net photosynthetic rate has a significant linear correlation with yield,and there was a certain competition relationship between them.Although the stem diameter and plant height of tomato has no direct effect on the yield,it has a good regression relationship with the leaf area index,so it will indirectly affect the tomato yield.Excessively high or low leaf area index is not conducive to the yield,while the combination of high stem diameter and low plant height is easy to obtain a more appropriate leaf area index,which is conducive to better yield.(6)The ranking of the weights of the comprehensive benefits evaluation indicators both are the efficiency of irrigation water>quality>yield,the overall ranking of the comprehensive evaluation results show that the L2-0.6E is the best,followed by L2-0.8E,and the worst treatment was L3-1.2E.Therefore,L2-0.6E treatment is the optimal combination of planting row spacing and irrigation volume when the objective of pursuit for comprehensive efficiency is the best,and L2-0.8E treatment is the optimal combination of planting row spacing and irrigation volume for pursuing the goal of comprehensive quality optimization.When the water resources are adequate,L2-1.0E treatment is the optimal combination of planting row spacing and irrigation volume when only considering the yield and comprehensive quality.