Horticulture: predicting strawberry fruit infection by Mucor and Rhizopus using climatic conditions and pathogen inoculum levels

在过去的25年里，英国的软果产量增长了600%，现在价值15亿英镑。草莓采后的损失主要是由三种真菌病原体引起的：灰霉病菌、毛霉和根霉。水果腐烂造成的经济损失不是由于可销售水果的直接损失，而是由于如果在货物中检测到一个腐烂的水果，则主要是由于整批水果的拒收。在世界范围内，对草莓上的绿僵杆菌的流行病学和防治研究较多。包括英国在内的一些国家已经证明，利用病害预测模型可以有效地管理露天草莓上的灰绿杆菌。在受保护的种植制度下，英国最近的研究表明，收获后快速去除田间热量和随后的冷链管理足以在不需要使用杀菌剂的情况下管理灰霉病，类似于管理受保护的覆盆子作物上的灰霉病。这是因为在保护性种植条件下，几乎所有因灰孢杆菌造成的作物损失都是由于收获后潜伏感染的腐烂发展造成的。相比之下，由于毛霉和根霉都能感染果实并迅速导致采前水果腐烂，因此可能需要对这两种病原体进行采前管理干预。然而，目前对草莓毛霉和根霉侵染的预测和管理知识不足。本项目旨在填补毛霉和根霉引起的软腐病流行病学方面的知识空白。具体而言，它有三个具体目标：(1)收集根霉和毛霉侵染果实的田间数据；(2)建立、验证并完成草莓根霉和毛霉侵染风险的预测模型；(3)开发和计划商业项目合作伙伴（Berry Garden Growers）使用的模型实施。一旦实施，该模型可以被种植者用于有针对性的疾病管理。

Over the past 25 years soft fruit production has grown by 600% in the UK and is now valued at > £1.5 billion. Postharvest strawberry losses in particular are largely caused by three fungal pathogens: Botrytis cinerea, Mucor spp. and Rhizopus spp. Economic losses due to fruit rotting do not result from the direct loss of marketable fruit but due primarily to the rejection of whole consignment of fruit if a single rotting fruit is detected in the consignment.Epidemiology and management of B. cinerea on strawberry is well studied worldwide. Managing B. cinerea on strawberry grown in open field can be effectively achieved with the use of disease forecasting models as demonstrated in a number of countries, including UK. Under protected cropping systems, recent research in the UK has demonstrated that rapid removal of field heat after harvesting and subsequent cool-chain management are sufficient to manage grey mould without the need to use fungicides, similar to managing grey mould on protected raspberry crops. This is because nearly all crop losses due to B. cinerea under protected cropping result from post-harvest rot development of latent infections. In contrast, as both Mucor and Rhizopus can infect fruit and rapidly lead to visual, pre-harvest fruit decay, pre-harvest management intervention may thus be necessary for the two pathogens. Currently there is, however, insufficient knowledge to predict and manage the infection of Mucor and Rhizopus on strawberry.This project aims to fill the knowledge gap on the epidemiology of soft rot caused by Mucor and Rhizopus. Specifically, it has three specific objectives: (1) To collect field data on the infection of fruit by Rhizopus and Mucor;(2) To develop, validate and finalise models predicting the risk of infection of strawberry fruit by Rhizopus and Mucor;(3) To develop and plan model implementation for use by the commercial project partner (Berry Garden Growers).Once implemented, the model can be used by growers for targeted disease management.