- Downy mildew in pea has been reported in southern New Jersey.
- Bacterial leaf spot of parsley has been reported in southern New Jersey.
- Cucurbit downy mildew has been reported as far north as southern Georgia.
- 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 warmer weather have been ideal conditions for early-season damping off caused by Pythium root rot and Phytophthora crown rot. Growers should continue to scout on a regular basis and remain proactive in their fungicide programs as long as current weather patterns continue.
- 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 Crops Edition
Seasonal updates and alerts on insects, diseases, and weeds impacting vegetable crops. New Jersey Commercial Vegetable Production Recommendations updates between annual publication issues are included.
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Vegetable Disease Update – 5/31/19
IPM Update 5/29/19
Sweet Corn
IPM Personnel are still capturing low numbers of European corn borer (ECB) moths, although even these captures are fairly sporadic, and extremely low in the northern counties (see map at left). Despite this, single digit feeding percentages were found on Middlesex county whorl stage corn on Wednesday of this week. It is likely that ECB injury has occurred on early plantings in most areas, although it is probably very light. Early plantings grown under plastic will be at risk first, followed by the first bare ground plantings. Growers should begin scouting whorl corn for injury.
Look for the characteristic “shot-hole” type of feeding (photo below at right) and consider treating when infested plants exceed 12% in a 50 plant sample. As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left). It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time. This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.
Useful insecticides for this particular application include synthetic pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen. Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn. Control with these materials is very inconsistent.
The highest nightly trap catches of ECB for the week ending 5/29/19 are as follows:
Downer 2 | Centerton 1 | Hillsborough 1 |
Medford 2 | Elm 1 | Jones Island 1 |
Califon 1 | Folsom 1 | Oldwick 1 |
Does My Business Need A Spotted Lanternfly Permit?
With the closing of the Purdue grain facility in Bordontown, field crops growers are sending trucks to southeastern PA to deliver grain, and produce shippers and others may be working/delivering to warehouses there too. Burlington County Agricultural Agent Bill Bamka shares the following information about shipping into or out of Spotted Lanternfly (SLF) quarantine zones (including some northwestern NJ counties):
![Spotted Lanternfly adult](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2017/07/5524251-PPT-150x150.jpg)
Spotted Lanternfly adult with wings spread. Adults are about 1″ long
Spotted Lanternfly is an invasive insect recognized as a threat to agriculture in New Jersey and the United States. Multiple states in the Mid-Atlantic area have SLF populations and/or quarantines in place. Currently New Jersey has quarantines in Warren, Hunterdon, and Mercer counties. Pennsylvania has a quarantine area of 14 counties across the southeastern portion of the state. [Read more…]
Controlling Septoria Leaf Spot and Bacterial Leaf Blight in Parsley
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.
![Parsley SLS](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2014/04/Parsley-SLS-300x225.jpg)
Septoria leaf spot of Parsley
![Bacterial leaf blight on Parsley](https://plant-pest-advisory.rutgers.edu/wp-content/uploads/2019/05/20190520_161045-300x264.jpg)
Bacterial leaf blight on Parsley
IPM Update 5/22/19
Sweet Corn
Low numbers of European corn borer (ECB) moths continue to be captured in a few traps (see map at left). Several cold nights may have suppressed the first flight of the season, although declining ECB populations due to transgenic corn may play a part in the low catches. Early plantings grown under plastic will be at risk first, followed by the first bare ground plantings. Through the central counties, a few early corn plantings have reached the whorl stage. Growers should begin scouting whorl corn for injury. Look for the characteristic “shot-hole” type of feeding (photo below at right) and consider treating when
infested plants exceed 12% in a 50 plant sample.
The highest nightly trap catches of ECB for the week ending 5/21/19 are as follows:
Green Creek 2 | Crosswicks 1 | Pedricktown 1 |
Beckett 1 | Downer 1 | Princeton 1 |
Blairstown 1 | New Egypt 1 | Woodstown 1 |
Several corn earworm (CEW) individuals have been captured in blacklight traps this week. Catches occurred at Port Colden in Warren County, Matawan in Monmouth County and Woodstown in Salem County. These individuals likely represent a limited overwintered population to our south, and arrived on the southerly breezes that occurred over the weekend and early this week. There is little threat from these CEW at this time.
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.