咖啡树蒸腾速率与环境因子的关系

THE RELATIONSHIP BETWEEN TRANSPIRATION RATE OF COFFEE TREE AND ENVIRONMENTAL FACTORS

用统计学方法,定量研究了大田条件下四个咖啡品系:中粒种21、中粒种24—11、中粒种24—2和小粒种S288的蒸腾速率与环境因子的关系。结果表明,参试品系的蒸腾速率与太阳辐射、气温、叶温、VPD和相对湿度显著相关,其中,与太阳辐射呈直线关系,与气温、叶温和VPD呈指数曲线关系,与相对湿度呈抛物线关系。据此求出了相应的回归方程。五个环境因子对各品系蒸腾速率的影响各异,影响各品系蒸腾速率的主要因子,中粒种21为VPD和相对湿度,中粒种24—11为太阳辐射和VPD,中粒种24—2为太阳辐射和气温,而小粒种S288为太阳辐射、气温和相对湿度。依主要影响因子拟合出四个被测品系蒸腾速率的多元回归方程。由此多元回归方程估算得到的各品系蒸腾速率的多天平均理论值与实测值相当一致。

The study was made by statistical methods on the relationship between the transpiration rate of four coffee varieties, Coffea canephora 21, 24-11, 24-2 and Coffea arabica S288 with environmental factors in the field. The results indicated that the transpiration rate correlated significantly with environmental factors such as solar radiation, air temperature, leaf temperature, VPD and relative humidity.The transpiration rate of four coffee varieties correlated linearly with solar radiation;exponentially with air temperature, leaf temperature and VPD; and parabolically with relative humidity.The result of multiple regression analysis showed that five environmental factors have different effects on transpiration rate. The main factors affecting transpiration rate were VPD and relative humidity for Coffea canephora 21; solar radiation and VPD for Coffea canevhora 24-11; solar radiation and air temperature for Coffea canephora 24-2; solar radiation, air temperature and relative humidity for Coffea arabica S288.multiple linear regression equations of four varieties measured were respectively worked out between transpiration rate and main factors. The theoretical means of transpiration rate for many days calculated from these equations are in conformity to the measured values.