一年二收巨峰葡萄碳水化合物平衡模型之校準及模擬

Abstract

臺灣多以一年二收系統生產巨峰葡萄，一年二收系統可根據收穫季節分為冬收果以及夏收果兩季。兩收生長季分別經歷不同的氣候，造成果實及產量的差異。不同氣候條件會使葡萄生長出現差異，影響植株的光合作用以及呼吸作用，並進一步影響碳水化合物平衡。為了測試上述假說，本研究修改碳水化合物平衡模型「VitiSim」並校準，以應用於臺灣一年二收系統之巨峰葡萄碳水化合物平衡的模擬。再將完成校準的模型分別輸入冬、夏兩季的長期氣候資料進行模擬以及比較。VitiSim之校準以葉面積及果實鮮重作為指標，並以2009年夏收果為比較標準。模擬結果顯示，與長期平均氣候相比2009年夏收果生長季之氣候可使葡萄藤固定較多CO2。冬收果及夏收果生長季CO2固定量差異小。全株光合作用的季變化則顯示於冬收果生長季初期快速增加，但是到了中期之後則漸漸下降，另一方面，於夏果雖初期光合作用增加較緩和，但是到了生長季末期仍不斷上升。夏果生長季氣候可滿足較高的果實碳水化合物需求，顯示夏果生長季氣候可使葡萄負載較多的果實。

Double cropping system has been applied to grape production in Taiwan for four decades. According to the season of harvest, the cropping cycles are defined as winter and summer cropping cycles. Obviously, the growth of two cropping cycles experiences different weather and causes noticeable differences on fruit composition and yield. Weather effect on vine growth might further affect photosynthesis capability and respiration. Therefore, carbon balance trend of the vine changes with weather experienced. To test this hypothesis, ‘VitiSim’ a carbon balance model was adapted to on ‘Kyoho’ grapevines grown under a double cropping system in Taiwan. Simulations based on weather data of two cropping cycles were conducted. The model was calibrated to fit the leaf area and berry fresh weight development in 2009 summer cropping season. Simulations showed that CO2 accumulation of a vine was higher in 2009 summer cropping season than the long term average weather condition. Simulation based on long-term data suggested CO2 accumulation in the two cropping season was similar. Whole-canopy photosynthesis quickly increased in the early season but declined after the mid season during the winter cropping cycle. On the other hand, during the summer cropping cycle, initial whole-canopy photosynthesis was slow but consistently increased during the season. The simulation suggested summer season might have higher crop capacity because fruit demand was satisfied more than winter.