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

Fruits become susceptible to infection by Mucor and Rhizopus spp. from 'pale yellow/white' onwards with the susceptibility increasing with increasing fruit ripeness and infection can complete within a few hours (Agyare 2016). To relate the incidence of fruit infection to the inoculum level and weather conditions, the shorter the period of fruit exposure to pathogen inoculum, the better it is. We will collect samples of fruit from a commercial field to estimate percent infection by Mucor and Rhizopus within a 24 h period based on a protocol developed in the previous Innovate UK project. We will expose attached developing fruit to external inoculum for 24 h before surface sterilisation and incubation for assessment of fungal infection. Airborne inoculum will be estimated with a plate trapping method based on the MYA-K selective medium for Mucor and Rhizopus (developed at NIAB East Malling), and weather conditions (temperature and humidity) recorded at an interval of 15 min for the 24 h exposure period. The new data set (disease incidence, inoculum, weather) will be combined with the previous data set collected in the IUK project for development and validation of prediction models for the two diseases. Furthermore, Berry Garden Growers (BGG) IT engineers will be involved in discussing implementation of the models into their cloudy server in which several pest and disease models developed at NIAB East Malling had already been implemented and used by BGG growers. The project will be divided into three work packages (WPs): WP1. Field data collection. Two commercial tunnels will be used for sampling from early June to October to estimate percent infection by Mucor and Rhizopus within a 24 h exposure period. WP2. Statistical modelling. Data will be analysed to develop/validate/finalise predictive models. WP3. Implementation and project management. Develop a plan for implementing the models for practical use.