植物器官体积变化连续测微法指导果树自动化灌溉合理指标的研究

对盆栽葡萄（VitisviniferaL．）、苹果（MaluspumilaMill．）、山楂（CrataeguspinnatifidsBunge）和枣（ZiziphusjnyubaMill．）4种果树在不同水分营养状况下茎于微变化过程中的日最大收缩量（MDS）、日净增长量（DG）、当日完全复原所需时间（RT）等3个重要指标进行研究，结果表明：3个指标都比叶片日出前水势对土壤水分营养状况的反应灵敏得多；随着土壤可利用水分的不断减少，山楂和枣的MDS急剧增加，而葡萄和苹果的MDS减小，不同类型果树之间的反应不一致；在土壤水分状况较好时，4种果树的DG的变化平缓，变化幅度较小；在良好的土壤水分条件下，4种果树的RT随着土壤相对持水量的下降而迅速延长，并在土壤水分含量降低到一临界值以下时维持在24h。因此，在应用植物器官体积变化连续测微法指导果树灌溉时，MDS和DG并不适于单独作为所有果树的自动化灌溉指标，而RT作为果树自动化灌溉指标较为理想。

Rational Parameter for Irrigation Scheduling Automation Used in Fruit Trees by Micromorphometric Method

The three important parameters,maximum daily shrinkage (MDS),daily growth (DG),and recovering time(RT) of stem diameter were studied during drought periods on four kinds of potted fruit trees, grape (Vins vinifera L. ), apple (Mains pumila Mill. ), Chinese hawthorn (Crataegus pinnatifida Bunge),and jujube(Ziziphu jujuba Mill. ). The above three parameters are all much more sensitive than predawn leaf water potential(LWP) in response to soil water status.The evolution of the stem MDS following a decrease in the soil water content was variable depending on fruit tree species:Stem MDS increased reapidly in Chinese hawthorn and jujube trees while that of grape and apple trees decreased as soil drying. DG of all trees decreased slowly with the reduction of soil water availability under relatively high soil water content. RT increased sharply as soil drying,then remained 24 hr if the soil water content was under a critical level. It is suggested that RT is a comparatively ideal parameter when the micromorphometric method is applied in the orchard for irrigation scheduling automation in fruit trees，but it is difficult to use MDS or DG as a single parameter for irrigation automation in the field.