不同水势对温室黄瓜蒸腾及室内湿度的影响

Effects of Different Water Potential on Transpiration of Cucumber and Humidity in Greenhouse

设置9个水势处理（-5kPa〈T1≤0kPa；-10kPa〈T2≤-5kPa；-15kPa〈T3≤-10kPa；-20kPa〈T4≤-15kPa；-25kPa〈T5≤-20kPa；-30kPa〈T6≤-25kPa；-35kPa〈T7≤-30kPa；-40kPa〈T8≤-35kPa；-45kPa≤T9≤一40kPa）。研究不同水势条件对温室黄瓜蒸腾及室内湿度的影响。结果表明，不同水势下温室黄瓜蒸腾量的日内变化差异显著，以晴天12：00—13：00之间的蒸腾量为指标，开始产生水分胁迫的处理（T3）比无水分胁迫处理（T2）下降了23．3％；而水分胁迫的非气孔限制阶段T7，T8和T9处理，分别比无水分胁迫处理（T2）下降了72．4％，81．5％和84．0％。不同水势下蒸腾量的日际变化亦表现出显著差异，T1在阴天的日蒸腾量比晴天下降了60．0％；随着水势的下降，晴天和阴天的日蒸腾量差异逐渐减小，T3在阴天仅比晴天下降了36．1％；当水势下降到T7以下时，晴天和阴天的日蒸腾量差异不显著，均围绕在50g上下波动。温室内的日平均相对湿度为63．63％～78．63％，比生产中的大水漫灌导致的温室内的相对湿度（85％-90％）降低了9（秋冬季）～24（春夏季）百分点（平均16．5百分点）。温室内空气湿度的降低，不仅可有效减少病害的发生，而且可实现生产的节本增效。

Nine water potential treatments （ -5 kPa 〈 T1 ≤ 0 kPa; - 10 kPa 〈 T2 ≤ -5 kPa; - 15 kPa 〈 T3 ≤ - 10 kPa; -20 kPa 〈 T4 ≤ - 15 kPa; -25 kPa 〈 T5 ≤-20 kPa; -30 kPa 〈 T6 ≤-25 kPa; -35 kPa 〈 T7 ≤-30 kPa; -40 kPa 〈 T8 ≤ -35 kPa; -45 kPa ≤ T9 ≤ -40 kPa） were designed to study the effects of different water potential on transpiration of cucumber and humidity in greenhouse. The results demonstrated that daily variation of transpiration amount of cucumber crop under different water potential conditions differed significantly. Employed the transpiration amount between 12：00 to 13：00 in sunny days （maximum transpiration amount per hour） as analysis index, comparing with no water stress condition （T2）, water stress beginning stage （T3） and non-stomatal limitation stage of water stress （T7, T8 and T9） decreased by 23.3%, 72.4%, 81.5% and 84.0%, respectively. Interdiurnal variation of transpiration amount of cucumber under different water potential conditions also demonstrated significant difference. Daily transpiration amount in cloudy days decreased by 60.0% than in sunny days under T1. The difference of daily transpirantion amount in cloudy days and in sunny days decreased with water potential falling down and it was only 36.1% under T3. The difference was not significant and fluctuated at 50 g when water potential below -30 kPa. Daily averaged relative humidity in greenhouse was 63.63%-78.63% and decreased by 9 （autumn-winter）-24 （spring-summer） percentage points （averaged 16.5 percentage points） comparing with the condition in popular priduction （85%-90%）. The decreasing of humidity in greenhouse will help to not only prevent diseases but also enhance production benefits.