Andy Wyenandt

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

Greenhouse Sanitation Important for Disease Management

Proper greenhouse sanitation is important for healthy, disease-free vegetable transplant production.

Efforts need to be made to keep transplant production greenhouses free of unnecessary plant debris and weeds which may harbor insect pests and disease. Efforts need to be taken throughout the transplant production season to minimize potential problems.

  • All equipment, benches, flats, plug trays and floors should be properly cleaned and then disinfested prior to use.
  • Any weeds in or around the greenhouse structure should be removed prior to any production.
  • Any transplant brought into the greenhouse from an outside source needs to be certified ‘clean’, as well as, visually inspected for potential insects and diseases once it reaches your location.

Remember, disinfestants, such as Clorox, Green-Shield, or hydrogen dioxide products (Zerotol – for commercial greenhouses, garden centers and Oxidate – commercial greenhouse and field), kill only what they come into direct contact with so thorough coverage and/or soaking is necessary. The labels do not specify time intervals for specific uses, only to state that surfaces be ‘thoroughly wetted’. Therefore, labels need to be followed precisely for different use patterns (i.e., disinfesting flats vs. floors or benches) to ensure proper dilution ratios. Hydrogen dioxide products work best when diluted with water containing little or no organic matter and in water with a neutral pH.

 

Cucurbit Downy Mildew Alert – 9/16/22 – Pumpkin and Butternut Squash

Cucurbit downy mildew has been confirmed on pumpkin and butternut squash in New Jersey. Cucurbit downy mildew was confirmed on summer squash in southern New Jersey a few weeks ago and cucumber earlier this season.  Remember, some CDM isolates fall into Clade I which predominately infect watermelon, pumpkin, and squash, where other CDM isolates in Clade II predominately infect cucumber and cantaloupe. All cucurbit growers should scout on a regular basis and initiate a weekly CDM fungicide program.

For more information on CDM, the clades, and CDM control please click here.

Infected leaf

Cucurbit downy mildew sporulating on the underside of an infected cucumber leaf.

Cucurbit Downy Mildew Alert – 9/3/22

Cucurbit downy mildew has been confirmed on summer squash in southern New Jersey. This is the first report of CDM on summer squash in the state this growing season. CDM was also confirmed in watermelon on Long Island this week.  Remember, some CDM isolates fall into Clade I which predominately infect watermelon, pumpkin, and squash, where other CDM isolates in Clade II predominately infect cucumber and cantaloupe. All cucurbit growers should scout on a regular basis and initiate a weekly CDM fungicide program.

For more information on CDM, the clades, and CDM control please click here.

Mildew on leaf

Cucurbit downy mildew sporulating on the underside of an infected cucumber leaf.

Pepper anthracnose ALERT: 08-09-22

Pepper anthracnose has been confirmed in southern New Jersey. For more information on its control please click here.

Vegetable Disease Update: 08-08-22

Basil downy mildew found in southern New Jersey – ALERT 7/29/22

Basil downy mildew has been confirmed in field grown basil in southern New Jersey. This is the first confirmed report of BDM in the state this growing season. To date, there have been very few reports of BDM in the mid-Atlantic and Northeast regions this growing season. The extremely, hot dry weather these past three to four weeks have not been ideal for its development. However, all basil growers are encouraged to scout their fields or greenhouses on a daily basis and should consider initiating a preventative fungicide program. [Read more…]