Rutgers University | New Jersey Agricultural Experiment Station | Pesticide User Responsibility

Andy Wyenandt

This is an archive of Dr. Wyenandt's posts on the Plant and Pest Advisory.

May 25, 2014

Recognizing Angular Leaf Spot in Cucurbits

Angular leaf spot is common in New Jersey and the region. It often shows up during cool, wet weather and isolated rain.

Symptoms of angular leaf spot in cucurbit.

Symptoms of angular leaf spot in cucurbit.

Angular leaf spot of pumpkin. Note the 'shot holes' in the leaf.

Angular leaf spot of pumpkin. Note leaf ‘shot holes’.

Angular leaf spot will first appear as, small water-soaked lesions which will expand until they reach a larger leaf vein resulting in the angular looking symptoms on leaves. Under heavy disease pressure, the bacteria will infect fruit causing small, water-soaked circular spots. In many cases once weather conditions become dry again, infected tissue in leaves will die and fall out leaving the characteristic ‘shot hole’ symptoms. Control of angular leaf spot begins with the application of labeled rates of fixed copper plus mancozeb to help suppress the spread of the disease until hot, dry weather returns.

Filed Under: Vegetable Crops Tagged With:
May 25, 2014

Controlling Phytophthora Blight in Pepper

With the wet weather, conditions for the crown rot phase of Phytophthora blight have increased. Phytophthora blight typically develops in low-lying areas of fields after a heavy rain and can spread quickly throughout the entire field. Planting on a ridge or raised, dome-shaped bed will help provide better soil drainage. [Read more…]

Filed Under: Vegetable Crops Tagged With:
May 24, 2014

Severe Hail in Southern New Jersey

tomato hail

Severe hail damage on pepper transplants.

On Thursday night areas of southern New Jersey were hit with severe hail. A significant amount of damage was done on all crops across a few of counties (Salem, Gloucester, and Cumberland).  [Read more…]

Filed Under: Vegetable Crops Tagged With:
May 10, 2014

Sunscald Injury in Transplants

Now that the weather is beginning to cooperate and temperatures are warming up, be cautious about sunscald developing on the stems of transplants, especially those being set onto black plastic mulch. With a little planning ahead potential losses to sunscald injury can reduced significantly.

Sunscald

Sunscald injury on stems of newly transplanted pepper seedlings caused by stems laying against edges of black plastic mulch on hot, sunny days.

A transplant coming straight out of the greenhouse and directly into the field has not been exposed to much direct sunlight. Add that with black plastic mulch and you have a lot of heat aim directly at the tender tissue of the transplant. All transplants should have some time to harden-off outside the greenhouse before going into the field, a day or two, is better than none at all, the longer the better if time and space allow.

Sunscald typically appears as the slow bleaching out of the stem that will typically appear only on one side. Often this starts to appear right where the stem meets the black plastic mulch. In many cases if the stem is touching the mulch, the sunburn will start there and the transplant will begin to fall over as if the stem was broken.

When transplanting, make sure the holes in the plastic are wide enough to keep the stem from coming into contact with it. In some cases growers will fill in the transplant hole with soil to help keep the transplant upright before between-row herbicides are applied. ‘Leggy’ transplants that lay across plastic mulch and even those transplanted onto bare ground are prone to sunscald injury.

Filed Under: Vegetable Crops Tagged With: ,
May 5, 2014

2014 Potato and Tomato Reports Available

The 2014 Potato and Tomato Reports are now available! Just scroll over the Vegetable Crops tab on the Plant and Pest Advisory homepage and links for each report will appear.

Like in years past, both reports will be updated twice a week for those interested in timing their fungicide applications according to Tom-Cast and Blightcast from NEWA information. Real-time updates can also be obtained by going directly to the NEWA site, selecting the nearest weather station to your farm operation, and clicking on the appropriate model. It is that simple! As always, should Late Blight appear in our region sometime this season a PPA Alert will be sent out to those signed up.

Filed Under: Vegetable Crops Tagged With:
May 5, 2014

Basil Downy Mildew Reported – NJ 5/5/14

Basil downy mildew was reported in a greenhouse in Virginia last week. The first question I asked myself was, “How can that be?”

BDM_OW_GH

Basil downy mildew on overwintered sweet basil plant.
Note symptoms on leaf top side and downy mildew spores on leaf underside.

Well, before I could come up with a good answer, basil downy mildew was found in a high tunnel in Salem County today. I don’t have any of the details from the VA report yet, but I do have a lot of information from New Jersey.

The infected plants in question, roughly 12 mature potted sweet basil plants, were just a few plants that were left over from last fall and carried over the winter in a non-heated high tunnel on benches with heated mats and row cover. The heated mats and row cover were for protecting other crops. Interestingly, the basil did not freeze out, somehow managed to survive the winter without much heat, and produce downy mildew spores once the outside temperatures rose.
[Read more…]

Filed Under: Vegetable Crops