Citrus Tree Abiotic and Biotic Stress and Implication of Simulation and Modeling Tools in Tree Management

摘要

Plant abiotic and biotic stress is related to unfavorable and environmental constraints. As a warm climate tree fruit crop, citrus (Citrus sinensis (L.) Osb.) is adapted to a wide variety of soil types and growth conditions. However, when waterlogging, soil acidity and root weevil infestation occur simultaneously, citrus roots can be injured from anaerobic disturbance, oxygen deprivation and root injury, which can lead to tree decline. Multi-year spatial overlay patterns of plants, insects and soilsmay yield management insights for reducing plant biotic and abiotic stresses. This paper attempts to summarize abiotic and biotic stress of citrus trees associated with soil anaerobe, soil waterlogging, environmental acidity and Diaprepes abbreviatus root weevil infestation, and to give an overview of the development of new biological tools such as greenhouse simulation and model prediction tools for integrated fruit production of citrus. Greenhouse simulation studies and a series of multi-year studiesat citrus orchard scale have been conducted across center and southern counties in Florida. The results showed that citrus tree decline was correlated with anaerobe and high soil Fe concentrations (P < 0.05), and citrus tree biotic and abiotic stress isdirectly reflected by low leaf stomatal conductance, flooding root damage, weevil larval root feeding injury, and anaerobic-related soil redox potential. Citrus rootstock roots were injured up to three weeks of submergence and flooded-roots were more susceptible to Diaprepes root weevil feeding than non-flooded roots. Time series analysis reveals that root adult weevil population outbreaks were associated with warm air temperatures across a period of three years (r = 0.49, P < 0.0067), suggesting that warming conditions would contribute to more tree biotic stress. Greenhouse simulation tools and time series forecast models have the implication in reducing biotic and abiotic stress of citrus trees.