Effects of aerobic irrigation on growth and light response characteristics of greenhouse tomatoes
To improve the yield and light use capability of greenhouse tomatoes,based on a greenhouse pot experiment,three dissolved oxygen mass concentration gradients of 5,15,25 mg/L(i.e.treat-ments A1,A2 and A3)were set up.Six models,such as Rectangular hyperbola model,Nonrectangu-lar hyperbola model,were used for the light response curve fitting of greenhouse tomato leaves.The effects of different oxygenation levels on greenhouse tomato biomass and yield,light response curve model and light response parameters were analyzed.The results show that the aboveground fresh weight,aboveground dry weight,root fresh weight,root dry weight,root-shoot ratio and yield of toma-toes reach the maximum under treatment A2,which are increased by 25.65%,17.62%,13.35%,36.80%,16.25%and 33.82%,respectively,compared to treatment A1(P＜0.05).Aboveground fresh weight,aboveground dry weight and yield of tomatoes are highly significantly and positively correlated with stomatal conductance(GS),intercellular CO2 concentration(Ci)and transpiration rate(Tr),while root dry weight is significantly and positively correlated with GS and Ci,and extremely signifi-cantly positively correlated with Tr.The light response parameters such as maximum net photosynthetic rate(Pn max),light saturation point(LSP),dark respiration rate(Rd)and apparent quantum efficien-cy(α)of greenhouse tomato leaves under treatment A2 reach the maximum,and light compensation point(LCP)reaches the minimum.Among the six models,Rectangular hyperbola modified model R2 is the largest,all higher than 0.992,and the RMSE and MAE are the smallest,which below 0.447 and 0.383,respectively.The fitted values for parameters such as Pn max,LSP,LCP and Rd are closer to the measured values.Therefore,a dissolved oxygen concentration of 15 mg/L is more helpful for high yield of greenhouse tomatoes.The Rectangular hyperbola modified model is the optimal model suitable for fit-ting the light response curve of greenhouse tomatoes under aerobic irrigation.
greenhouse tomatoaerobic irrigationdissolved oxygen mass concentrationyieldlight response curve
万方数据
维普
