Text Box: VegNet Vol. 11, No. 11.  June 23, 2004
Ohio State University Extension Vegetable Crops
On the WEB at:  http://vegnet.osu.edu
 

 

In This Issue

1. Anthracnose on Pumpkins and Vine Crops

2. Aster Yellows Alert

3. Crop Reports

4. Closeup: The Meigs/Washington County and the Henry County Vegetable Tours

 

 

 

 

Anthracnose on Pumpkins and Vine Crops

By R. Precheur and R. M. Riedel

 

The warm, moist, rainy weather in spring has led to an outbreak of anthracnose in pumpkins and other vine crops. Lesions appear near or on leaf veins especially on the underside of the leaf. They are roughly circular and are light brown in color. The leaves may be distorted and the centers of the lesions may crack or drop out creating a shot hole appearance. Portions of the leaf may become necrotic beyond the location of the lesion on the leaf vein. Pictures are available at the VegNet website: http://vegnet.osu.edu/problem/pb071503.htm. Pictures provided by Dr. Andy Wyenandt, Plant Pathology now with Rutgers University. If you have the publication “Important Pests and Diseases of Pumpkin in Ohio”, go to the section entitled “Important Foliar Diseases of Pumpkin” on the top half of page 2. Growers should check their fields for symptoms. Chemical contol may be obtained through the use of protectant or eradicant fungicides such as Bravo, Equus, Quadris, Tanos, Cabrio and Amistar. See page 222 of the 2004 OH Vegetable Production Guide for recommended materials and specific rates.

 

 

Aster Yellows Alert!!!!!  By Casey Hoy and Sally Miller

Aster leafhoppers were collected from Celeryville, Ohio, in early June and were tested by PCR for aster yellows.  The assays identified 8% infected leafhoppers.  Large populations of aster leafhoppers have been reported in both the Celeryville and Hartville muck crops areas.  Early lettuce has been reported with approximately 7% and 13% aster yellows symptomatic plants in Celeryville and Ottawa County, respectively.  Each of these percentages is quite high for this time of year and could lead to serious aster yellows incidence in susceptible crops. Epidemics are especially likely in lettuce crops, which allow both the disease organism and the leafhopper to reproduce well.  The aster leafhopper feeds on a wide range of plant species, however, and the aster yellows disease agent, a phytoplasma, infects a wide range of plants.  Other crops can be affected by the disease as well, especially celery and carrots.

 

Lettuce plantings should be treated with insecticides to prevent the aster leafhopper from vectoring the disease.  The key times to treat lettuce plantings are approximately 10-14 days after transplanting or crop emergence and approximately 21 days before harvest.  The first timing is to protect the current field from infections that would show up before harvest, whereas the second is to prevent any leafhoppers that have developed in the field from moving the disease to other fields.  Use an insecticide with long residual activity for the early applications (for example Capture, Baythroid, Mustang, Warrior, Sevin, dimethoate;  Assail may also be effective but has not been tested as thoroughly) and one with rapid and thorough control of nymphs for the later applications (for example a pyrethroid or Lannate).    A distance of at least 60 yards between susceptible fields, or moving any new plantings as far as possible from existing plantings, can also reduce the movement of leafhoppers between fields and slow the disease.  

 

Crop Reports ( R. Becker, Brad Bergefurd B. Precheur, and Dusty Sonenberg)

 

Northeast OH (June 22, 2004)

Vine crops are starting to show signs of disease including alternaria and anthracnose. Cucumber beetles are also becoming more active.

The first planted sweet corn is in the tassling stage with corn borer levels as high as 42% infestation. Rust was also found in sweet corn on 6/21.

Early blight has been found in both tomatoes and tomatoes, though very light so far.

Two spotted spider mite, flea beetle and Colorado potato beetle have gone over threshold in several fields of eggplant.

 

Southwest OH (From: June 16, 2004)

Some areas of Southern Ohio have been receiving excessive amounts of rainfall, some areas over 4 inches the past week, whereas other parts such as southern Clinton County have had less than 1 inch of rain in the past 3 weeks, with irrigation taking place. Sclerotinia is showing up in high tunnel tomatoes, Goliath variety. Harvest of high tunnel fresh market tomatoes continues into week three of harvest. Septoria leaf blight is showing up in fresh market tomatoes in the field. Harvest of mature greens has begun. Harvest of cabbage, cucumbers, pickles and summer squash is in full swing. Harvest of snap beans and half runner beans continues. Sweet corn is in the blister stage with  harvest to begin on corn planted under plastic in about 5 to 7 days. Non plastic planted corn will begin in about 12 days. Phytophthora blight is showing up in Aristotle variety of pepper, in low areas of fields where standing water has been occurring with all the recent rains, with Ridomil Gold applications being made to these fields.  Tarnished plant bug populations are somewhat high in tomato. Harvest of greens including kale, mustard and collard is just about complete and yields and quality have been excellent. Harvest of Kohlrabi is about 74% complete with excellent quality. The chain stores were hesitant at first with taking early shipments since California was still shipping into the midwest but now they have switched to Ohio crop. Sweet corn is being sprayed for the presence of corn borer. Planting of sweet corn, snap beans, pumpkins, tomato, summer squash, winter squash, gourds, melons, watermelons, potatoes, cucumbers, pickles and peppers continues this week. Keeping up with fungicide and insecticide spray programs has been tough but growers are getting the job done. Cucumber beetles populations are increasing on vine crops.

 

Southeast and Northwest OH; Last week’s Vegetable Tours

The first tour of the week was the annual Washington/ Meigs Vegetable tour. This year the tour was held in Meigs county on June 15 at the J. Scott Hill Produce. Prior to the tour vegetable crops were surveyed throughout the county. Weather has been warm and crops have moved along nicely. Heavy rains hit over the previous weekend and growers were anxious for a little drying so they could resume field operation such as necessary sprays. Sweet corn was about 10 days from harvest at the time and some growers will probably begin picking for sure by this weekend. A company representative found some rust in early sweet corn. There was also a report in northeast OH (see above). Growers should keep an eye out for rust development since early infestations can affect yield and quality especially in later plantings. See recommendations in the 2004 OH Veg Guide, page 234.

Plastic sweet corn on June 15 in Meigs County

 

 Fresh market bell peppers seem to be on target for early July harvest (see pictures below).

 

 

It won’t be long before these fresh market bell peppers are ready for picking in Meigs county

 

Tomatoes were showing red color at several locations. A little bit of early blight and some Buckeye rot has been reported in some locations. Cabbage is still being harvested but starting to wind down

 

Northwest Ohio Vegetable Crops Tour – A Huge Success!

- by Dusty Sonenberg, OSU Extension Agent, Henry Co.

 

The Northwest Ohio Vegetable Crops Tour was held on Thursday, June 17th in Henry County.  The day was a huge success with an attendance of over 40 producers, consultants, extension agents and state specialists.  The tour began at the Vorwerk Brothers Farms, near Liberty Center, with a meal sponsored by Ag. Credit and two field visits viewing a bell pepper field and cucumber/pickle field.

 

Processing bell peppers will be grown for red peppers, (above left). Jodie Stearns takes a close look at Vorwerk Brothers pickle field.

 

  

Pickle field (above left). Slight cucumber beetle damage at the edge of the field.

 

 The second stop of the day was at Baughman Farms, Inc., just south of Napoleon, and included discussion about irrigation, sub-irrigation and field drainage as well as chemical application using an air assist sprayer.

 

Air assist sprayer at Baughman Farms which they use for all their crops (above left). Close-up of air assist cone and spray nozzle inside (above right).

 

Field visits at Baughman Farms included a look at green beans, carrots, potatoes, and parsley.

 This fresh market snap bean field is not the earliest but should be read by early to mid-July.

 

Tom Baughman shows the tour his Italian Plain Leaf parsley field. Just one of eight ingredients for the famous V8 beverage.

 

R&R Greenhouse was the third stop on the tour to learn about the hydroponic lettuce production.  Water quality, light intensity and duration, as well as plant diseases were discussed. 

 Hydroponic lettuce (above left) and early stages of development (above right). Seeds are placed in small osmocote cubes for germination prior to placement on the nutrient tracks.

 

The day ended with a tour of the Campbell Soup Company in Napoleon, which was led by Charlie Weber.

 

The day was a great opportunity for several local producers and OSU Extension State Specialists to meet and discuss issues as well as view vegetable production in Henry County and Northwest Ohio, and gain a better understanding of the vegetable processing that takes place at the Campbell Soup Company.