“黄冠”梨树茎直径微变化规律研究

Study on the Microchange Rule of Stem Diameter of ‘Yellow Crown’ Pear Trees

以"黄冠"梨树为试验材料,分别设定2个处理:充分供水处理(Well-irrigation,WI)和逐步干旱处理(Gradual-drought,GD),通过连续监测"黄冠"梨树茎直径、土壤水势(SWP)和日平均温度(T)等环境因子,研究梨树的茎直径微变化规律,为进一步利用梨树茎直径微变化来指导梨树节水灌溉提供参考依据。结果表明:WI处理和GD处理的日变化趋势有明显差异,GD处理的茎直径日最大收缩量(MDS)明显小于WI处理。GD处理的茎直径日最大值(MXSD)随着时间的延长,呈先升后降的抛物线趋势;随着土壤水势的下降,GD处理的茎直径日最大收缩量、日增长量(DI)和日复原时间(RT)与土壤水势之间分别呈很好的开口抛物线、斜率为正和斜率为负的线性关系趋势;GD处理的茎直径日最大收缩量与日平均温度、空气相对湿度(RH)和光照强度(L)呈显著的正相关,而WI处理的茎直径日最大收缩量与日平均温度、空气相对湿度和光照强度呈显著的负相关;WI处理的DI,不受空气相对湿度、光照强度和风速的影响,但受日平均温度的影响显著,呈负相关;GD处理的DI,不受空气相对湿度和风速的影响,但显著受日平均温度和光照强度的影响,为负相关。综上所述,在GD处理中,土壤水势与DI之间的线性关系更具实际意义,可以用DI作为指导梨树灌溉的指标。

Using the’Yellow Crown’pear tree as the test material,the stem diameter,the soil water potential(SWP)and the air temperature(T)were continuously monitored.The micro variation of the stem diameter of the pear trees was studied.The results showed that the diurnal variation trend of the full water treatment(Well-irrigation,WI)and the gradual drought treatment(Gradual-drought,GD)was obviously different,and the maximum daily shrinkage(MDS)treated by GD was obviously smaller than that of WI treatment.The maximum stem diameter(MXSD)of GD showed a parabolic trend which rose first and then decreased as time went on;with the decrease of SWP,the MDS,the daily growth(DI)and the daily recovery time(RT)and the SWP were a good linear relationship,positive slope and negative slope;the MDS treated by GD had a significant positive correlation with the daily mean temperature(T),air relative humidity(RH)and light intensity(L),while the MDS in WI treatment was negatively correlated with T,RH and L.The DI treated by WI was not affected by RH,L and wind speed,but it was negatively correlated with T,and the DI treated by GD was not affected by RH and wind speed,but it was significantly influenced by T and L,which was negative correlation.In GD treatment,the linear relationship between SWP and DI was more practical,and DI could be used as an index to guide pear irrigation.