Effect Of Spraying Biogas And KH₂PO₄ On The Leaves Photosynthetic Characteristics And Fruit Quality Of Nectarine (Prumes Per Sick Var.Nectarina Maxim)

Taking nectarine (Prunus persica var. Nectarina Maxim) "Yan-guang" of a four-year protected cultivation as experimental material.Effect of biogas and KH2PO4 slurry spraying on nectarine photosynthetic characteristics was studied in this paper. The results showed that:1. Spraying 0.3% KH2PO4, nectarine of light saturation point (LSP),at the time of light-saturated photosynthetic rate (Amax) and the apparent quantum yield (AQY) were higher, Light compensation point (LCP) was lower. CO2 compensation point (CCP)was lower, while the CO2 saturation point (CSP), CO2 saturated photosynthetic rate (Amax) and carboxylation efficiency (CE) were increased.2.Spraying KH2PO4 also increased soluble sugar content and TSS-TA ratio, had little effect on titratable acidity and vitamin C content.3.Set out the contents of N,P,K,Fe,Ca,Mg,Mn,Zn and B 9 indexes of quality of fruit which were weight per fruit, the flesh firmness, the soluble solids content and the anthocyanin content.The result showed that Biogas can increase the alimentation of lamina,contents of the nine elements were increased in the mass, but content of Mn,Mg element appeared reducing completed with the CK, only one date of the six transactions was above the CK, The dates of contents of elements presented trend that the dates were climbing at first and then falling on the graph, when applied biogas 75%,the contents of all the elements behaved the best.4. At the same time the biogas could also improve the quality of fruit, biogas had remarkable effect on soluble sugar content, the weight per fruit, vitamin C content and TSS-TA ratio, also presented trend that the dates were climbing at first and then falling on the graph, and when applied biogas 75%,the dates of the quality behaved the best.The result showed that biogas can improve both the alimentation of lamina and quality of nectarina, and when applied biogas 75%,all the indexes behaved best.5.The results showed that light saturated photosynthetic rate (Pn) and the content of chlorophyll (a+b), chlorophyll a, chlorophyll b were increased by 9%, 20.3%,50% and 8.7% respectively, when spraying 75% biogas slurry compared with the control.It had insignificant changes in light compensation point and apparent quantum yield. CO2 compensation point was decreased by 5% while CO2 saturation point, CO2 saturated photosynthetic rateand carboxylation efficiency increased by 21%,12% and 57% respectively, when spraying 75% biogas slurry compared with the control.Diurnalaccumulated photosynthetic products of functional leaves were increased by 35% when spraying 75%biogas slurry compared with the control.Water utilization rate (WUR), stomata conductance (Gs) and transpiration rate (Tr) were also increased using spraying, causing a decrease of stomata limitation and a delay of "photosynthetic depressed" in noon.6.The curves of net photosynthesis rate were "double-peak curve". It played key role in the decline of the photosynthetic rate.