Septoria leaf spot (SLS) in Parsley can cause significant losses in fields where it has become established. Like other Septoria’s, the leaf spots produced on parsley look much like the leaf spots produced on tomatoes and other crops. Septoria leaf spot overwinters from year to year on infected debris so long crop rotations of 2 or more years are important to help reduce disease pressure. During the season, SLS will spread rapidly with each subsequent rainfall and/or overhead irrigation event. Therefore, early detection and preventative fungicide applications are key to successfully controlling SLS. Unfortunately, very few fungicides are currently labeled making control difficult.
Controlling Strawberry Fruit Rots – 2019
Fruit rots in strawberry can cause significant losses if not recognized early and controlled. The use of good cultural practices such as keeping fields weed-free and promoting good drainage, long crop rotations, and preventative fungicide applications are critical.
Pathogens such as anthracnose, gray mold (Botrytis), and leather rot (Phytophthora) can become systemic problems in strawberry plantings and can be difficult to manage over the lifetime of the planting.
The use of mulch (matted rows) to prevent/reduce soil splashing and keeping fruit from coming into direct contact with the soil surface can be beneficial in organic production systems where conventional fungicides cannot be used. Use of long crop rotations and staying away from areas of the farm with known instances of any of these pathogens is also important. Remember that same species of Colletotrichum that causes fruit rot in pepper and other crops can also infect strawberry.
Damping-off: Identifying and Controlling Early-Season Damping-off Pathogens
It is extremely important to know which pathogen is causing damping-off problems and which fungicide to properly apply. The key to controlling damping-off is being proactive instead of reactive. Always refer to the fungicide label for crop use, pathogens controlled, and application rates.
Damping-off is caused by a number of important vegetable pathogens and is very common during the spring. Damping-off can kill seedlings before they break the soil line (pre-emergent damping-off) or kill seedlings soon after they emerge (post-emergent damping-off). Common pathogens that cause damping-off include Pythium, Phytophthora, Rhizoctonia and Fusarium spp.
Control of damping-off depends on a number of factors. First, is recognizing the conditions which may be leading to the problem (i.e., weather/greenhouse growing conditions) and second, identifying the pathogen causing the problem.
Conditions Favoring Damping-off
Although all four pathogens are associated with damping-off, the conditions which favor their development are very different. In general, Phytophthora and Pythium are more likely to cause damping-off in cool, wet or overwatered soils that aren’t allowed to dry out due to cloudy weather or cooler temperatures. Conversely, Rhizoctonia and Fusarium are more likely to cause damping-off under warmer, drier conditions especially if plug trays are kept on the dry side to help reduce transplant growth. [Read more…]
Understanding Damping-off Pathogens During Seeding and Transplanting
Damping-off is caused by a number of important vegetable pathogens and is very common during transplant production and early-spring. Damping-off can kill seedlings before they break the soil line (pre-emergent damping-off) or kill seedlings soon after they emerge (post-emergent damping-off). Common pathogens that cause damping-off include Pythium, Phytophthora, Rhizoctonia and Fusarium spp.
It is extremely important to know which pathogen is causing the damping-off problem and which fungicide to properly apply.
Vegetable Disease Update – 5/21/19
- The cool, damp weather the past week has been ideal for downy mildew development on spring crops. Growers are advised to scout fields on a regular basis
- The heavy rains and damp, cool weather have been ideal conditions for early-season damping off caused by Pythium. Growers should continue to scout on a regular basis and remain proactive in their fungicide programs as long as current weather patterns continue.
- Cercospora leaf spot on swiss chard has been reported.
- Bacterial leaf spot of parsley has been reported.
- Basil downy mildew has been reported in greenhouses in North Carolina.
- Cucurbit downy mildew has been reported as far north as St. Lucie County, Florida.
- For more information on controlling these and other important diseases please see the 2019 Mid-Atlantic Commercial Vegetable Production Guide. The guide is available for FREE online by following the links on the Plant and Pest Advisory website. Hardcopies of the 2019 guide can be purchased through your local county Extension office.
Vegetable Disease Update – 5/14/19
- The cool, damp weather the past week has been ideal for downy mildew development on spring crops. Growers are advised to scout fields on a regular basis
- The heavy rains and damp, cool weather have been ideal conditions for early-season damping off caused by Pythium. Growers should continue to scout on a regular basis and remain proactive in their fungicide programs as long as current weather patterns continue.
- Sunburn on stems of newly transplanted peppers on black plastic mulch has been reported.
- Cercospora leaf spot on swiss chard has been reported this past week.
- Cucurbit downy mildew has been reported as far north as St. Lucie County, Florida.