Phytophthora blight caused by Phytophthora capsici is one of the most economically important diseases in pepper, tomato, and cucurbit production in New Jersey. The pathogen was first identified in a pepper field in southern New Jersey in 1971. Each year for the past three decades Rutgers has evaluated new bell pepper cultivars and breeding lines for their resistance to P. capsici in field trials at the Rutgers Agricultural Research and Extension Center (RAREC) near Bridgeton, New Jersey, and in some years, at research trials on farms near Vineland, NJ. The pathogen, an oomycete – ‘water mold’ is favored by warm weather and wet soils during the production season and can survive between seasons in the soil as oospores. Once found in a field, the pathogen can establish itself, and be very difficult to control even with the use of fungicides because of resistance development. Fortunately, in bell pepper, highly resistant or intermediate resistant cultivars to Phytophthora blight have been commercially-available for over 20 years now and have been used extensively by bell pepper growers throughout the state. Each year, Rutgers also evaluates each cultivar for their fruit quality characteristics (e.g., color, wall thickness, number of lobes, and development of ‘silvering’) to make sure they meet the needs of growers. Unfortunately, phytophthora resistant cultivars such as ‘Paladin’ which have been used extensively in southern New Jersey for the past 20 years appears to be breaking down. Because of increasing reports of bacterial leaf spot and copper resistance in recent years, bell peppers grown in NJ at some point will need to consider growing those cultivars with X10R resistance and phytophthora blight resistance. Importantly, for organic bell pepper growers, if you have not already done so, you should be evaluating these new lines to see if they meet your needs. The easiest way to mitigate both diseases are to start with genetic resistance. Below are the bell pepper variety and bacterial leaf spot reports for 2021.

Click to access Rutgers-Pepper-Phytophthora-Blight-Final-Report-2021.pdf

Click to access Rutgers-Bacterial-Leaf-Spot-Final-Report-2021.pdf

For more information on recommended bell pepper cultivars please visit the Pepper Section in the 2022/2023 Mid-Atlantic Commercial Vegetable Productions Recommendations Guide.

By: Andy Wyenandt and Wesley Kline