Abstract:
Fruit trees are important agricultural and forestry plants; their life is a complex system. Digital technology can help humans effectively perceive and recognize the life, production, and ecosystem of fruit trees, and then realize intelligent production. Nowadays, reducing the planting cost of fruit trees, improving the quality of fruit products, and promoting the marketing of fruit products, digital technology has increasingly become a hot research topic of fruit tree planting, and it is also an urgent need for the development of fruit industry. In this review, firstly, the concept and connotation of digital fruit tree were discussed systematically under the category of digital plant technology, its concept was defined as a theoretical technology and technical service platform system that comprehensively uses digital technology to study life, production, and ecosystem of fruit trees through high-throughput information acquisition and intelligent processing, and to realize the quantification, visual perception, and cognition of complex system of fruit trees. Secondly, the framework of the digital fruit tree technology system was put forward, its main modules included the classification of digital elements, digital data acquisition, construction of the digital cognitive model, and digital application services, then, the hierarchical structure of the technical framework was described in detail. Thirdly, the research progress of key technologies of digital fruit trees were systematically reviewed, including five aspects: 1) the fruit tree phenotype information acquisition technologies; 2) the fruit tree growth environment data acquisition technologies; 3) the fruit tree three-dimensional model construction and visualization technology; 4) the fruit tree digital breeding technologies; 5) the fruit big data and virtual reality technology. At the same time, the current development progress and technical bottlenecks of various key technologies were reviewed. Among them, the phenotypic technology runs through the lifeline of digital fruit trees, which is the key link in the construction of a digital fruit tree technology system. Under different scales of the sky, air, and earth, therefore, the performance characteristics, the phenotype platform flux, the accuracy and efficiency of phenotype acquisition sensors were summarized in this review. Indeed, phenotypic information acquisition and analysis technology are still one of the bottlenecks. Digital fruit tree technology has been widely used in many links of fruit production. So, fourthly, the effects and challenges were reviewed and discussed in detail from the perspective of fruit industry application. At present, the main application scenarios of digital fruit technology include tree shape management, growth monitoring, planting management, digital agricultural technology training, digital brand building, agricultural tourism digital service, and so on. Typical application cases were classified and introduced to provide application ideas for researchers and fruit production management personnel. Fifthly, the development trend, research hotspots, and technical breakthrough direction of digital fruit trees prospected, including big data technology, artificial intelligence technology, multi reconfiguration technology, virtual reality technology, and so on. To improve the intelligence level for the digital fruit tree technology system, the different technologies should be integrated deeply. This review could provide a useful reference for the further development of the digital fruit trees, for knowing the research hot spot, and for understanding the application bottleneck.