Seedbed Time Again
Yes, another Vidalia Onion growing season has started. Folks have been busy planting seedbeds for the last 2 or 3 weeks. We’ve had several hot days during this time, and folks are busy running irrigation to help the seed come up. It has also been very dry and rain has not been in the forecast for the last few weeks. At least for onion seedbeds, this may be a good thing since we have not had to worry about packing rains or other bad weather yet. At the Vidalia Onion and Vegetable Research Center, we have also planted our seedbeds for our onion trials this year.
Here are a few things to watch out for in seedbeds as we start another season:
Mole Crickets – Most everyone is using some type of insecticide on their seedbeds for insect control. Really, the only options we have for soil insects are Lorsban and Diazinon. These two usually give us good control, but occasionally we may have to make a repeat application. Scout your onion seedbeds for mole cricket tunneling. They can often be seen right after working up a freshly prepared seedbed.
Damping- Off – Seedling disease, or Damping -Off, is primarily caused by Pythium and Rhizoctonia pathogens. According to Dr. Bhabesh Dutta, our Extension Plant Pathologist, most of the damping off you would see in onion seedbeds is caused by Pythium. This is usually due to cool and/or wet conditions as seeds are germinating and emerging from the soil. The warm, dry weather we have been experiencing the last couple of weeks is not really conducive for Damping-Off to develop. However, keep your irrigation practices in mind early on. I know that many folks have to water twice a day after they plant, in order to keep the tops of the beds moist. Over-watering could contribute to development of Damping-Off, so just be sure that you are not watering more than you need to or completely saturating your soil.
If you are concerned about Damping-Off or the weather patterns make a big change, Ridomil Gold SL (active ingredient Mefenoxam) is labeled for this disease. There are other Ridomil products out there labeled for onions, such as Ridomil Gold Bravo SC (Mefenoxam + chlorothalonil) or Ridomil Gold MZ WG (Mefenoxam + Mancozeb). However, keep in mind that these formulations are primarily for control of other foliar diseases and do not have enough “Ridomil” (mefenoxam) in the labeled rates to provide the expected control of Damping-Off.
IMPORTANT NOTE: Ridomil Gold SL is only labeled for SOIL applications. This means that it needs to be applied to the seedbeds before onion emergence. It is not labeled as a postemergence foliar application.
I have also heard of folks using Captan. This product was labeled for Damping-Off control years ago, but is no longer labeled for onions. However, Ridomil is considered a better choice for control anyway.
2019-2020 Vidalia Onion Variety Trial
This year, we received 45 entries into our trial which evaluates yield and flavor characteristics of these onions. We planted our seedbeds on September 16th. Take a look at the varieties we planted this year from each seed company:
Solar Seed: Candy Joy, Candy Kim, Candy Ann
Nunhems: Plethora, Vidora, 2002(white onion), Sofire(red onion), Althea(white grano), Vulkana(yellow globe), Mata Hari(red onion), Dulciana(grano)
Sakata: Sweet Harvest, Sweet Jasper, SON-109Y
Emerald: Emy 55126, Emy 55455, Emy 55457
East West Seed: EWR 1019 “Sabrina”
Bejo: Macon, Red Hunter(red onion), Red Sensation(red onion), Red Duke(red onion), Alison, Tania, Pirate, J3014, J3009
Seminis: Sweet Agent, Sweet Azalea, Sweet Magnolia, Century, Granex Yellow PRR,
Wannamaker: New Frontier, WI-129
Shamrock: Quick Start, Fast Track, Sweet Emotion
DP Seeds: Sapelo, 1407, GA Boy, Lucille(red onion)
NT Seeds: NT-AC0901
Takii: Superex, Rio Dulce