The majority of Vidalia onions are produced as a transplanted crop. Seeding in high density plantings in September is followed 8 to 10 weeks later by transplanting to final spacing. This practice is labor intensive and expensive. Direct seeding would save on labor, cost, and time. Traditionally, transplanting has been done because of better winter survival, more uniform stands, and better irrigation management during seedling emergence. Beginning 5 years ago, we began evaluating direct seeding onions. Initially, seedstems (bolting) and lack of uniform stand establishment were the main problems. Sowing in September resulted in almost 100% seedstems and using a belt planter with raw seed resulted in poor singulation for uniform stand establishment. Mid-October ultimately proved to be the best time for sowing Vidalia onion seed. Earlier sowing resulted in more seedstems and later planting did not give the plants sufficient time to grow resulting in later stand loss during cold winter temperatures. Using polymer coated seed and a precision vacuum planter resulted in uniform, even stand establishment. Fertilizer requirements are almost half with direct seeded onions compared to transplanted onions with a reduction in the need for fungicides and herbicides. We have established direct seeded onions both with drip irrigation and overhead irrigation. There was concern that center-pivot irrigation would not be able to sufficiently irrigate fields during seedling establishment with the frequent hot fall days we experience. Since this work was initiated several growers have successfully produced direct seeded onions under center-pivot systems. Direct seeding Vidalia onions requires attention to detail because there is only one opportunity to get it right. Timing is also critical particularly with planting date and herbicide application.
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