Infections first occur on fruit tissue under the calyx. Fruit infections appear as soft, light brown, rapidly expanding spots. Both green and red fruit are susceptible to infection, but ripening fruit rots faster. Persistence And Transmission. Early season temperatures between 70 and 80 degrees F and wet weather are ideal for disease development.
Infection can also occur at lower temperatures when the plants are wet for extended periods.
The fungus usually infects the plant through dead or dying plant tissue. Fruit resting on the soil, touching another decayed fruit or dead leaves in dense foliage, are most commonly attacked. Spores of the fungus can be spread by the slightest touch or by wind. Pickers handling infected fruit often spread the disease. Use plastic mulches to prevent fruit-soil contact.