Even though much of New Jersey has had wet weather recently, which is more favorable to Pythium and Phytophthora development, Rhizoctonia root rot has been reported over the past few weeks in a number of crops. Rhizoctonia root rot, caused by Rhizoctonia solani, is an important soil-borne fungal pathogen with a very large host range. The pathogen can survive saprophytically on living or dead plant material (organic matter) or as sclerotia in the soil (for more than 3 years). Disease development is favored by warm temperatures, dry (or very well drained) soils and stressed plants. Symptoms of Rhizoctonia root rot may begin as stunted plant growth (with poor root systems) with the appearance of brown lesions at the base of the stem causing wilting with lesions eventually girdling the stem and killing the infected plant. Rhizoctonia root rot infections only extend about an inch above the soil surface (Figure 1), unlike Phytophthora blight infection which can extend much farther up the stem. [Read more…]
Diagnosing Southern blight and White mold in tomato and pepper
There have been a few reports of Southern blight (Sclerotinia rolfsii) and White mold (Sclerotinia sclerotiorum) on tomato and pepper in New Jersey. Southern blight is much more common in vegetable areas south of the state where summer temperatures remain hotter (above 90°F) for longer periods of time. Like white mold, it can survive in the soil for many years. Symptoms of Southern blight include infection at the base of the stem at the soil line. The resulting infection will girdle the plant causing wilt and death. The fungus will produce white, cottony mycelium and very small, spherical sclerotia which are often have a tannish, brown color.
White mold is more common than Southern blight in New Jersey, and like Southern blight, once introduced into a field or high tunnel it can very difficult to control. The pathogen produces large black sclerotia on the surface and inside infected stems. If sclerotia of either pathogen make their way back into the soil, both can survive for years causing significant problems.
All infected plants need to be removed immediately and disposed of properly to help reduce the chances of sclerotia returning to the soil.
For more information on chemical control please see the 2022/2023 mid-Atlantic Commercial Vegetable Production Recommendations Guide.
Symptoms of Southern blight on infected pepper plant. Note the numerous, small white to tan colored sclerotia on the stem.
White mold of tomato. Note the large black sclerotia developing inside the brittle stems.
REMINDER – Vegetable Research Plot Tour at RAREC Tonight
Wednesday, August 24, 2022, 4:30 pm (meet at the shelter near the parking lot)
Rutgers Agricultural Research & Extension Center
121 Northville Rd., Bridgeton, NJ (Upper Deerfield)
PESTICIDE CREDITS approved for this event:
1A (AGRICULTURAL PLANT) – 07
10 (DEMONSTRATION & RESEARCH) – 07
PP2 (PRIVATE APPLICATOR CATEGORY) – 07
4:30 – Welcome and Intros – Rick VanVranken, Atlantic County Agricultural Agent
5:00 – 8:30 pm Tour of research plots and discussions with Rutgers Extension Specialists
Thierry Besancon, PhD, Extension Weed Specialist for Specialty Crops
- Cover-Crops for Row Middle Weed Management in Plasticulture Tomato.
- Cover-Crops for Row Middle Weed Management in Plasticulture Cucumber.
- Crop Safety of Delayed Preemergence Herbicide Application for Cole Crops (Broccoli and Cabbage)
Andy Wyenandt, PhD, Specialist in Vegetable Pathology
- Bacterial Leaf Spot Development in Pepper and Tomato in NJ
- Copper Resistance Development in Bacterial Leaf Spot
- Basil Downy Mildew Breeding Program Update
- Bell and Non-bell Phytophthora Tolerance Trials
Joe Ingerson-Mahar, PhD, Vegetable IPM Coordinator
- Comparing the response of corn earworm to GMO and non-GMO sweet corn varieties and the resistance to BT corn
2022 Annual Vegetable Twilight Meeting & Research Tour
Wednesday, August 24, 2022, 4:30 pm (meet at the shelter near the parking lot)
Rutgers Agricultural Research & Extension Center
121 Northville Rd., Bridgeton, NJ (Upper Deerfield)
PESTICIDE CREDITS approved for this event:
1A (AGRICULTURAL PLANT) – 07
10 (DEMONSTRATION & RESEARCH) – 07
PP2 (PRIVATE APPLICATOR CATEGORY) – 07
4:30 – Welcome and Intros – Rick VanVranken, Atlantic County Agricultural Agent
5:00 – 8:30 pm Tour of research plots and discussions with Rutgers Extension Specialists
Thierry Besancon, PhD, Extension Weed Specialist for Specialty Crops
- Cover-Crops for Row Middle Weed Management in Plasticulture Tomato.
- Cover-Crops for Row Middle Weed Management in Plasticulture Cucumber.
- Crop Safety of Delayed Preemergence Herbicide Application for Cole Crops (Broccoli and Cabbage)
Andy Wyenandt, PhD, Specialist in Vegetable Pathology
- Bacterial Leaf Spot Development in Pepper and Tomato in NJ
- Copper Resistance Development in Bacterial Leaf Spot
- Basil Downy Mildew Breeding Program Update
- Bell and Non-bell Phytophthora Tolerance Trials
Joe Ingerson-Mahar, PhD, Vegetable IPM Coordinator
- Comparing the response of corn earworm to GMO and non-GMO sweet corn varieties and the resistance to BT corn
Diagnosing Southern blight and White mold in tomato and pepper
There have been a few reports of Southern blight (Sclerotinia rolfsii) and White mold (Sclerotinia sclerotiorum) on tomato and pepper in New Jersey. Southern blight is much more common in vegetable areas south of the state where summer temperatures remain hotter (above 90°F) for longer periods of time. Like white mold, it can survive in the soil for many years. Symptoms of Southern blight include infection at the base of the stem at the soil line. The resulting infection will girdle the plant causing wilt and death. The fungus will produce white, cottony mycelium and very small, spherical sclerotia which are often have a tannish, brown color.
White mold is more common than Southern blight in New Jersey, and like Southern blight, once introduced into a field or high tunnel it can very difficult to control. The pathogen produces large black sclerotia on the surface and inside infected stems. If sclerotia of either pathogen make their way back into the soil, both can survive for years causing significant problems.
All infected plants need to be removed immediately and disposed of properly to help reduce the chances of sclerotia returning to the soil.
For more information on chemical control please see the 2022/2023 mid-Atlantic Commercial Vegetable Production Recommendations Guide.
Symptoms of Southern blight on infected pepper plant. Note the numerous, small white to tan colored sclerotia on the stem.
White mold of tomato. Note the large black sclerotia developing inside the brittle stems.
Phytophthora blight control in pepper in 2023
Phytophthora blight typically develops in low-lying areas after a heavy rain and can spread quickly throughout the entire field. Fortunately, New Jersey has been really dry this summer, but that does not need you don’t need to prepare for potential Phytophthora issues down the road. This is particularly important if are in fields with a known history of Phytophthora blight. Although the extended period of dry weather works against Phytophthora development, it does not mean it will not show up eventually. [Read more…]
