Pepper: Improved control of Fusarium internal fruit rot through increased knowledge exchange with the Netherlands and targeted application of plant protection products - phase 2

Project Summary:

Internal fruit rot of sweet pepper grown in glasshouses has been an increasing problem worldwide, including the UK, for the last 15 years. The disease causes some losses on production nurseries but more importantly Fusarium continues to be a frequent cause of rejection by packhouses and product returns from supermarkets. Losses vary greatly between crops and seasons. We have shown several weakly pathogenic Fusarium species are associated with the disease, notably F. lactis and F. oxysporum in the UK. Fusarium spores deposited on the stigma during flowering grow rapidly through the style resulting in infection of seeds and internal fruit wall. Work in PE 007 demonstrated that a single spray of Serenade ASO applied to a crop during flowering can reduce the incidence of infection in fruit developing from treated flowers by around 50%. In PE 022 (phase 1) we showed F. lactis commonly occurs on rockwool propagation blocks in production glasshouses, a previously unknown source of the fungus. We also found that a high proportion of flowers and young fruits (1-2 cm diameter) in commercial crops were infected with F. lactis, yet only a relatively small proportion of fruit develop internal fruit rot. Results from 2014 and plans for 2015 were shared between the pathology teams at Bleiswijk Research Station (Wageningen University) and ADAS. This project aims to reduce losses to Fusarium internal fruit rot through: (1) continued information exchange and discussion on the disease with Dutch researchers; (2) examination of pepper seeds as a source of F. lactis and F. oxysporum that leads to growth of the fungi in rockwool propagation cubes; (3) determining the reduction in fruit infection provided by one and several applications of Serenade ASO to a crop row, cube surface and floor; (4) determining if use of biopesticides / plant resistance inducers applied preventatively provide protection to flowers and/or fruit against infection and/or fruit rot development; (5) monitor occurrence of F. lactis in flowers, young fruit and mature fruit in an organic pepper crop and a conventional crop; (6) communication of results to growers.

Aims and objectives: