Onion Crop Update, March 5,2019
There has been a lot going on in the Vidalia Onion world lately. Growers have been busy managing for disease, insects, and fertility on their crops. I have been trying to get out and visit county agents and growers, and I still have a lot more to look at. Please don’t hesitate to call me if you need anything. My cell is 912-551-2204.
Save the Date – April 4th, 2019 – Vidalia Onion Field Day
Please go ahead and make plans to attend the Vidalia Onion Field Day this year. It will be held on Thursday, April 4th, 2019 at 12:00 noon, right here at the Vidalia Onion and Vegetable Research Center (8163 Hwy 178, Lyons, GA 30436). We will have a lot to show you this year and are looking forward to a great meeting. I will share the agenda with everyone very soon once it is finalized. Industry folks, If you are interested in being a sponsor for the field day this year, I will have details for that soon as well.
I have been getting reports of thrips from a few growers. Me and the other county agents have seen a few, but don’t have any high numbers to report. The standard scouting threshold for thrips in the “Vidalia Onion Production Guide” states to begin spraying when 5 thrips are found per plant:
“Spraying for thrips should begin when an average of 5 thrips are present per plant. However, research has indicated that a single spray of an effective insecticide when there is one thrip per plant can reduce subsequent thrip populations and reduce the number of subsequent insecticide sprays. Spraying within two weeks of harvest for thrips control does not appear to provide any benefit in terms of yield even if the threshold is exceeded. Thrips reduce yields in onion by reducing bulb size, thus, once the bulb has reached full size, thrips damage is inconsequential to yield. However, thrips may transmit some onion diseases and control near harvest may affect bulb quality.”
It can be a tough decision on when to pull the trigger for thrips control, especially since many of the insecticides can be expensive. Here are your options:
Growers have been very busy trying to protect onions against downy mildew, botrytis leaf blight (BLB), stemphyllium, purple blotch, and bacterial diseases. Botrytis leaf blight is showing up in many places, even where growers have been on aggressive spray programs. Some of you may be asking why your spray program has not provided the control you thought it would. Botrytis infection of onion leaves is tied directly to duration of leaf wetness, and we’ve had plenty of that lately. Keep using products in your spray program to help with botrytis leaf blight. Here is the most recent UGA research data on controlling Botrytis Leaf Blight (BLB) in onion: