CO_2施肥对大棚油桃光合作用及产量品质的影响

The Effects of CO_2 Enrichment on Photosynthesis, Yield and Quality of Nectarine in Greenhouse

棚内CO2 浓度日变化幅度远大于棚外 ;在天气晴好、光合旺盛、通风受阻时 ,棚内CO2 匮乏可成为光合作用的主要限制因子。在保护地条件下 ,油桃光合速率 (Pn)日变化由露地的双峰曲线变为三峰曲线 ,最大Pn比露地提前 2h ,在 8时左右出现 ;光合“午休”现象不明显 ;晴天棚内日平均Pn为 5 .97(CO2 ) μmol/m2 ·s,比露地降低17.2 5 %。棚内CO2 加富对油桃光合作用和产量、品质有重要影响 ,较大幅度地提高了上午 8时～ 12时之间的Pn和光能利用率 ,日平均Pn 6 .95 (CO2 ) μmol/m2 ·s ,比对照提高 2 5 .90 %。树体生长健壮 ,生物量 (未含果实 )增加 12 .4% ,比叶重增大 ,产量提高 19.80 % 。

The CO 2 concentration inside the greenhouse fluctuated within a much wider range than that outside the greenhouse. The insufficiency of CO 2 in the greenhouse might become the primary restrictive factor for photosynthesis especially in sunny days when photosynthesis was vigorous and the greenhouse was badly ventilated. Diurnal variation trend of net photosynthesis(Pn) of ‘Shuguang’ nectarine was a two peak curve in open field, but the diurnal variation trend of Pn inside the greenhouse was a three peak curve and the maximum Pn appeared at about eight O'clock in the morning, two hours earlier than that in open field. Average Pn in a sunny day inside the greenhouse was 5.97 (CO 2)μmol/m 2·s, 17.25 % lower than average Pn ( 7.00 CO 2μmol/m 2·s)in open field.CO 2 enrichment inside the greenhouse had the important effects on the photosynthesis, yield and fruit quality of nectarine. Pn and PUE during 8:00～12:00 O'clock was markedly enhanced. Diurnal average Pn was 6.95 (CO 2)μmol/m 2·s, 25.90 % higher than that of control plot. CO 2 enrichment made the trees grow healthily and strongly. Biomass exclusive of fruits increased by 12.4 %. The yield was 19.80 % higher than that of the control and the fruit quality was also improved.