Onion seed can be treated in several ways prior to planting to improve quality and yield potential. The term “seed treatment” typically refers to the application of insecticides and/or fungicides to the seed to help protect the seeds and young seedlings from insect pests and fungal pathogens. 

Diseases affecting the roots and stems of onions can significantly impact the yield, quality, and storability of onion bulbs, and because the pathogens are present in the soil, these diseases can be difficult to control. The pathogens infect through the plant’s roots or basal stem plate. 

There are many planting methods and configurations of plant spacing used for onion production in North America. Onions can be direct-seeded, transplanted with field-grown or greenhouse-grown transplants, or planted using onion sets, and onions are planted on flat-ground and raised beds.