UGA Fungicide Spray Guide for Vegetable Diseases is out. Growers please contact your Extension Agent to get a copy of the same.
Please see the link to access the extension bulletin: https://extension.uga.edu/publications/detail.html?number=b1534.
Resistance to FRAC Group 11 fungicides (Quadris and Cabrio) in fungus causing cucurbit anthracnose in GA
We have detected insensitivity of Colletotrichum sp. (causal agent of anthracnose of cucurbits) to FRAC group 11 fungicides (Quadris and Cabrio) in multiple commercial fields in GA. Further confirmation in our lab indicated that 70 to 80% of the isolates are either highly resistant or moderately resistant to Quadris and Cabrio. These observations suggest that managing anthracnose […]
The outlook for problems with whitefly transmitted viruses does not look good for fall 2020 vegetable crops. Several viruses were reported at low levels at the end of the spring crops and have already been detected in early fall crops/experiments. This combined with rapidly increasing whitefly populations (and continued hot, dry weather) indicates we will […]
I believe everyone knows that whitefly populations have been building dramatically the last few weeks. Whiteflies love hot dry weather and reproduce rapidly under our current conditions. While we are probably not as bad as we were in 2017 (maybe a month behind), we are far ahead of the last two years. Populations are higher […]
Mr. Clarence Codod (Grad Student) has been scouting 18 commercial vegetable fields in Tift, Colquitt and Worth counties for whitefly and viral diseases. Here are some of the important details from our Spring scouting (Apr 7- Apr 21) Whitefly adults are more prevalent and occur in higher numbers in brassica (broccoli and cabbage) crops in Tift and Colquitt […]
Downy mildew has been detected on cucumber in Echols County today by Mr. Justin Shealey. These observations indicate that inoculum of downy mildew is currently in southern GA counties and under favorable conditions potential disease outbreak in cucurbit crops can occur. I would suggest our cucurbit growers to look for the downy mildew symptoms in their fields and start applying protective spray of below stated fungicides. Watermelon: Rotation (foliar application) […]
A VSC News Article: Vidalia Onion Crop Looks ‘Favorable’ Despite Presence of Downy Mildew Disease in Localized Areas (by Clint Thompson)
By Clint Thompson Vidalia onion producers have begun harvesting the early maturing varieties this year, and Chris Tyson is excited about the potential of this year’s crop. “The Vidalia onion crop definitely looks favorable this year. We are anticipating a quality harvest,” said Tyson, University of Georgia Cooperative Extension area onion agent at the Vidalia […]
We have confirmed Downy Mildew of onion in the area. Thanks to the keen eyes of our growers, and fast confirmation from our county agents (Jason Edenfield and Derrick Bowen), Downy Mildew of Onion has been positively confirmed in our area. Please protect your crop as necessary.
Just as a reminder, these are the products we are recommending for downy control:
Product Efficacy Rating
Omega 500 moderate
*Note about Omega: We believe Omega has better “curative” activity, and would be the better option if you have downy present in your fields. The Omega 500 label also specifically says “DO NOT use an adjuvant with Omega 500F on this crop.”
Orondis Ultra moderate
*Note about Orondis Ultra: The label specifically states, “For ground or aerial applications, a spreading/penetrating type of adjuvant such as a non-ionic surfactant, organosilicone, or blend must be added at labeled agricultural use rates
Bravo moderate to low
Zampro moderate to low
Phosphites low (but can help)
What does this mean for our crop?
We still have a ways to go on some onions. Onions that are more than 10 days from digging should take precedence for treatment. If onions are within a week or two of digging, a decision to treat is a judgement call that you will have to make on a case by case basis.
The weather conditions over the next few days are calling for highs in the 80’s, with no rain forecasted until next week (unless you get some rain today). This type of weather is typically not as favorable for downy mildew spread, but please don’t let this stop you from protecting your crop. We still have a long way to go on many onions, and it can definitely continue to spread. Pictures of the infected plants from this morning are included.