Time Series Analysis of Capsicum annuum Fruit Production Cultivated in Greenhouse

摘要

Hydroponics production of bell peppers (Capsicum annuum L.) in greenhouses is characterized by fluctuations of the number of fruits produced over the time. Different environmental influences as well as plant characteristics probably have an effect onthe yield pattern. The first aim of this work was to describe and analyse the cyclic fruitset and yield pattern and to determine if a simple method could be developed for bell pepper harvest prediction based on time series analysis. We found a delay between fruitset and harvest of 7 and 5 weeks for the monitored colored and green cultivars respectively. A first model was based on a weighted linear relation between the yield and the number of fruits set taking into account the observed delay. A second model, based on a weighted yield of the previous 3 weeks, resulted in lower standard errors of forecast. A combination of both previous methods even performed better. For the colored cultivars, the latter model could be improved by making use of differentinput time series of climate variables while the same model for the green harvested cultivar could hardly be improved. We think the reason herefore was the bigger variability in fruit age of the green harvested fruits. This can be explained by the fact that the harvester has no clear fruit color indication to determine the harvest color and therefore uses other criteria like fruit size and hardness.