温室茄子不同生育期茎直径变化特征及其与气象因子的关系

Stem diameter variation characteristics during different growth stages of eggplant in greenhouse and its relation to meteorological factors

为了寻找诊断温室作物水分状况的可靠的茎变化指标,对春季温室条件下茄子不同生育期、不同土壤含水量茎变化关键指标进行了研究。结果表明,各生育期低水分处理的茎直径(MDS)日最大收缩量基本上大于高水分处理的MDS,但它们的变化趋势基本一致,这种一致性是由气象因子所致;苗期的日生长量(DI)从未出现过负值,高水分处理的累积DI要大于低水分处理的累积DI,且MDS和DI之间呈现出一定程度的负相关,而其余时期的DI基本上在DI=0附近波动;通过对MDS、DI和相关气象因子进行回归分析发现,MDS和气象因子有更好的相关性,基本上各时期MDS和相对湿度呈负相关关系,与温度、辐射、空气饱和差呈正相关关系;且气象因子对低水分处理的茎变化影响大于对高水分处理茎变化影响,由此提出建立合理土壤水分条件下的气象因子对MDS的预测模型作为诊断温室作物水分状况、实现自动灌溉的方法。

In order to find a reliable index of stem variation to diagnose water content of crops in greenhouse,an analysis was made of some key indexes of stem variation under high and low soil water content in greenhouse in spring.The result indicated that,the maximum daily shrinkage（MDS） of low soil water content was mostly bigger than that of high soil water content during three growth stages,but they both shared the same variation trend which was caused by meteorological factors.Furthermore,there was no negative daily increase（DI） in seedling stage opposite to fluctuation above or below DI=0 during the other two growth stages.In addition,the gross DI of high soil water content was bigger than that of low soil water content during seedling stage,and the relationship between MDS and DI was negative correlation too.Through regression analysis between MDS,DI and relative meteorological factors respectively,we found that MDS had a better correlation with meteorological factors than DI,and there were positive correlations of MDS to radiation,temperature,VPD and negative correlation to relative humidity,which influenced the low soil water content＇s MDS more sharply than that of high soil water content.Because of the evidences above,we came up with the thought of establishing a model under seemly soil water content between MDS and meteorological factors as the key point of diagnosing water content inner crops of greenhouse and opening the automatic irrigation system.