TYPES, VARIETIES & CUTS
Green onions are often referred to as bunched or spring onions, salad onions, or scallions. Each refers to a densely planted, mildflavored immature-bulb onion of the common Allium cepa species. Many of today’s cultivars are hybrids of Allium cepa and Allium fistulosum (a Japanese bunching onion), which can produce either bulb or nonbulb plants. Day-length (short-day or long-day varieties dependent on hours of sunlight) influence growth characteristics, such as bulb development and size.
Varieties vary greatly, but White Lisbon is widely grown. Crystal Wax, Ebenezer, Eclipse, Hishiko, Ishikura, Kincho, Sweet Spanish, Tokyo Long, White Globe, and White Portugal are among the many other varieties available for growers depending on region and market specifications.”
References: North Carolina State Extension, Oregon State University, U.S. Food and Drug Administration/University of California, Davis Western Institute for Food Safety & Security.
PESTS & DISEASE
The onion family is vulnerable to a number of diseases from Botrytis leaf blight, Fusarium basal rot, and purple blotch to black mold, slippery skin, and smudge. Many of these maladies are not among the most common threats to bunched onions, though green onions are susceptible to common diseases such as bacterial soft rot, bulb rot, damping-off, downy mildew, grey mold, onion yellow dwarf virus, rust, smut, Southern blight, twister, white tip, and wilt.
Insects of concern include armyworms, bulb mites, click beetles, cutworms, leafminers, leek moths, nematodes, onion maggots, and thrips.