South Carolina: Downy Mildew Found on Cucurbits in Home Garden Center

**No cucurbit plants infected by downy mildew have been identified in NC big box stores, but growers and home owners should always inspect transplants before purchasing**

Earlier this week, Dr. Anthony Keinath at Clemson sent the following report to agents:

"My technician found cucurbit downy mildew (CDM) on yellow summer squash and zucchini plants at a Home Depot store in Charleston, SC on Wed. 4/6/11. There were several plants at bloom stage in 1-gallon pots with spots of downy mildew on about 25% of the leaves. Several CDM spots had begun to sporulate. (The plants also had powdery mildew, which was more severe than CDM.) The plants were grown in Miami, FL, and labeled with Home Depot tags. The garden manager pulled all of the remaining plants. However, it appears that some diseased squash plants were purchased between Wed. and Sunday, when I confirmed CDM.

Please check your local Home Depot store to see if they also had a shipment of diseased squash plants. These plants could be the start of an early epidemic of CDM in your area! If you find any diseased plants, please let me know. (Squash plants with powdery mildew only also should not be sold.)"

Dr. Keinath put together an informational fact sheet on this problem including control recommendations. Timely Talk: Cucurbit Downy Mildew.

Please revisit my blogpost from April 22, 2010 on diseases in home garden centers entitled "Don't Bring Problems in With Transplants! "

Use the "Search WNC Veggies" application at the top of the right hand menu to find pictures and descriptions of cucurbit downy mildew.

Greenhouse Growers Workshop

When?: Thursday, November 18. Registration starts at 8 am. Program runs from 9 am-4:30 pm

Where?: Mountain Horticultural Crops Research and Extension Center in Mills River

Who Should Attend?: This educational program is geared toward both the ornamental and vegetable greenhouse grower.

How much?: Registration is $10 per person and includes lunch. Registration is required by Friday, November 12. Click here for the brochure and registration form.

About the Program: In the morning, all attendees will learn the newest container designs, latest substrate options from Fafard and about releasing biologicals in the greenhouse. During lunch, you will learn how to improve your greenhouse efficiency. There will be two afternoon sessions, one for ornamental and one for vegetable growers.

The vegetable session will include talks about Commercial Production of Vegetable Transplants, Vegetable Varieties and Soil Fertility.
Click here for the complete agenda.

Come see, ask questions and network with other growers, specialists and industry representatives!

NC pesticide credits will be available.

Don't Bring in Problems with Transplants!

Healthy vegetable transplants in a local greenhouse.

This is the time of year when commercial growers and homeowners alike are preparing for transplanting of vegetable crops.

Warning: Don't bring diseases into your garden or field on transplants!

Purchasing and planting diseased plants into your garden or production field can cause big headaches and major problems later in the season.

Be sure to inspect transplants before you purchase them, especially from home garden centers! Often diseased vegetable starts find their way onto retailers' shelves.

Last year, there was a major problem with late blight on tomato transplants that were purchased from some garden centers. Though this was not a problem in North Carolina, the lesson is still an important one: Do not purchase any plants that have visible signs of disease including lesions, spots, specks, wilts, discoloration, etc!

Some disease problems to look out for are bacterial spot on tomatoes and peppers, damping-off on many different vegetable crops and late blight on tomato and potato.

In addition, always make sure your transplants have nice, healthy, white root growth. Pull a few plants out and inspect their root system. Also, handle your transplants with care. If you pinch the tender stem of a transplant too tightly, you could damage it and invite pathogens in for attack.

Pepper transplants which became diseased by Alternaria spp. after improper handling.

Dr. Mary Hausbeck from Michigan State University has just published an on-line report for greenhouse producers entitled: Transplant Diseases: Identification and Control. This publication includes conventional control measure for greenhouse producers that produce transplants, but it also includes some good identification tips for everyone purchasing or producing vegetable transplants.

*Special thanks to Dr. Kelly Ivors for reminding me about this important topic!*