Saturday, March 15 is the deadline for disposing of cull onions in Ada, Canyon, Gem, Payette, Owyhee and Washington counties, the Idaho State Department of Agriculture says.
That means there must be no culls onions deemed waste or not useable for human consumption on hand at any packing sheds, infields or at animal feed facilities on the morning of that day. Onions can be disposed of by pit burial, feeding, composting, spreading, chopping and shredding.
The larval stage of the onion maggot attacks and destroys portions of the onion bulb, providing an avenue for fungi and bacteria to cause bulbs to rot during storage, said Mike Cooper, chief of the department's plant-industries bureau. With consecutive years of wet springs, the insect has been known to destroy 80 percent to 90 percent of the crop. We frequently find the onion maggot in cull onion piles.
The maggot adult flies emerge in April and May and are attracted to the volatile odors given off by sprouting onions and new seedlings. Each onion maggot can destroy up to two dozen seedlings during its two-week lifespan, so crop damage can be substantial. If not properly disposed of, culls serve as breeding and egg-laying sites for the adult flies.
Cooper said that disposal regulations have been in effect for several years and work well. We have received excellent cooperation from the onion industry," he said.
Onions sorted after March 15 must be properly disposed of within one week. Trucks transporting onions should be covered to prevent spillage along roadsides.