DIRECT SEEDING VIDALIA ONIONS
George E. Boyhan*, Juan Carlos Diaz-Perez, Reid L. Torrance, Ronald H. Blackley
Jr., C. Randell Hill
University of Georgia, Department of Horticulture, East Georgia Extension Center, PO Box 8112, GSU, Statesboro, GA 30460, Email: gboyhan@uga.edu
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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