柑橘果园树体生长状态高光谱图像时间序列监测与生态适应性评价研究

Hyperspectral image for monitoring citrus production systems requires the understanding of how plant physiology, canopy structure, management and solar elevation affect the retrieved canopy reflectance during different stages of the phenological cycle. However, there is no report on the regulation mechanism of citrus tree production capacity combining real-time characteristic spectral separation for citrus tree by now. Hence, the project proposed to interpret a hyperspectral time series for a mature and healthy citrus orchard.The research results will be useful for development of citrus tree monitoring system and optimizing cultivation decision to lay the theoretical foundation, to promote the development of precision agriculture in citrus. The experiments carry out in the navel orange orchard located in the Three Gorges Reservoir Area,and based on the hyperspectral images time series data,biophysical parameters at the canopy level were derived and related to known observed physiological and phenological changes at the leaf level under different orchard management of pruning and preventing fruit abscission. Fractions of flowers,fruit, function leaves and shoot leaves were considered, and indices related to canopy structure chlorophyll content and canopy water status were calculated. Finally, the monitoring model of citrus tree production capacity are constructed combined with the physiological interpretation of a hyperspectral time series in a citrus orchard under different ecological environment using multi information fusion methods.

橘园树体生长状态高光谱监测需要结合不同生态果园栽培措施对不同品种的树体性状和生理信息在不同物候期的变化特征及其对高光谱图像的响应机制。为此，本项目开展基于高光谱图像时间序列的不同生态柑橘果园树体性状和生理信息解译与评价研究。研究内容包括：①不同物候期花、果实、不同叶龄叶片识别与特征参数提取研究；②基于高光谱图像时间序列树体物理结构参数提取和光合产物获取、分配相关生理信息提取研究；③冠层色素含量和水分状态提取研究；④不同生态柑橘果园树体生产力形成分析，采用关联分析法解析树体生产力与树体物理性状和生理信息参数的机理性关系。其研究成果将为柑橘优质、丰产资源筛选评价提供理论和工具上的支持，亦为研发实用化的柑橘树体监测预警系统和调优栽培决策奠定理论理论基础。

本研究通过开展树体性状和生理信息对橘园栽培措施响应机制及不同物候期光电监测技术研究，旨在建立基于时间序列的橘园树体性状和生理信息解译与光电监测评价技术体系。主要完成包括：①开展了橘园主要逆境（秋冬低温寡日照、夏季高温干旱胁迫）对橘园树体挂果能力和果实品质影响机理研究；②开展了栽培措施处理（人工补糖、激素保果和修剪整形等）对橘园树体挂果能力和果实品质发育的影响研究，并通过光电检测时间序列分析方法，阐明了主要逆境和栽培措施橘园树体物理性状和生理信息高光谱响应机制；③同步开展了上述处理不同物候期花、果实、叶片识别及光合产物获取、分配相关生理信息提取研究，筛选了橘园树体挂果能力和果实品质发育关键时期，并构建完成树体物理性状和植物生理信息光电监测模型，及监测效果验证；④通过开展不同生态柑橘果园树体生产力形成分析，构建了基于光电检测技术的橘园树体挂果能力和果实品质预测模型，并完成模型预测效果验证。其研究成果将为柑橘优质、丰产资源筛选评价提供理论和工具上的支持，亦为研发实用化的柑橘树体监测预警系统和调优栽培决策奠定理论理论基础。