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

Project summary:

Internal fruit rot of sweet pepper grown in glasshouses has been an increasing problem worldwide for approximately the last 14 years. In the UK a survey in 2007 showed infected fruits were present in many crops at levels from 1 to 37% (PC 260). 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. Several weakly pathogenic Fusarium species are associated with the disease, notably F. lactis and F. oxysporum. Fusarium spores deposited on the stigma during flowering grow 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%. The optimum time to apply sprays of plant protection products during the year is unknown. The potential benefit of treating rockwool cubes and crop debris is unknown. The harvest period over which a single spray to flowers provides continued protection is unknown. This project aims to reduce losses to Fusarium internal fruit rot through: (1) agreed information exchange and a joint work programme with Dutch/Belgium researchers; (2) examination of rockwool cubes as a source of F. lactis and F. oxysporum; (3) devising experiments to determine if the level of flower infection can be used to predict risk of fruit infection; (4) determining the duration of reduction in fruit infection provided by a single application of Serenade ASO to a crop row, cube surface and floor; (5) determining if use of biopesticides / plant resistance inducers applied preventatively provide protection to flowers and/or fruit against infection; (6) communication of results to growers.

Benefits to industry:

• The development of a robust platform for future collaborative, joint-funded work with Dutch and/or Belgium growers on protected edible crop diseases.
• Increased knowledge on pepper Fusarium internal fruit rot through coordinated work with Dutch and Belgium researchers.
• Development of a method to predict risk of Fusarium fruit rot through measurement of flower infection.
• Potential to apply targeted treatments to reduce Fusarium internal fruit rot through use of biofungicides and fungicides in periods when flower infection is increasing /high.
• Potential to reduce incidence of Fusarium internal fruit rot through use of protective sprays of biopesticides / elicitors to enhance natural plant resistance.
• Reduced risk of packhouse rejection, supermarket return and disruption to the supply chain.

Aims and objectives:

(i) Project aim:

To reduce fruit wastage due to Fusarium internal rot through knowledge exchange and by targeted application of plant protection products.

(ii) Project objectives:

Phase 1 (July 14 – Mar 15)

1. To liaise with the Dutch and Belgium researchers working on Fusarium internal fruit rot, exchange information and develop a coordinated, applied research programme;
2. To examine rockwool cubes as a source of F. lactis and/or F. oxysporum;
3. To examine the relationship between flower infection by Fusarium spp. and Fusarium infection in small fruit;
4. To communicate project outputs for immediate uptake by UK pepper growers.