A Cornell researcher crossed three varieties of yellow onion trying to find a line of higher- yielding plants, but instead came up with something unexpected.

While he shed tears, they were tears of joy: The researcher, Thomas W. Walters, Ph.D., had stumbled onto a sweet, pink onion. But, let's not mince words: The New York Sweet Blush variety is still in the commercial breeding process, said Walters, the Cornell plant breeder who discovered the onion by chance, and not yet ready for grocers' shelves. "Before onions were domesticated, they were probably pink and later bred to be yellow," Walters said. "Previous societies would have bred them that way because they probably preferred the yellow color."

The onion will be tested in small plots throughout New York this year. Walters hopes to begin working with seed companies interested in distributing seeds and seedlings as early as next season. For large-scale production of onion seed, male sterile versions of onion breeding lines are needed to make hybrid seeds that are uniform and more disease-resistant, as well as able to generate higher yields.

Toward that end, Walters was trying to make a male sterile breeding line of large, mild-sweet onions. By crossing a large, sweet yellow onion with a male sterile cross from Cornell and the U.S. Department of Agriculture -- MSU-8155-B and MSU-5718-A -- he inadvertently found the pink variation. His work is sponsored by the New York Onion Growers and by a consortium of seed companies that support vegetable breeding at Cornell.

"Before onions were domesticated, they were probably pink," Walters said. "Maybe previous societies bred them to be yellow and white because they preferred those colors." This was the "complementary factor" of onion breeding -- the pigment's enzymatic chain was broken at one time, perhaps thousands of years ago by prehistoric plant breeders selecting unpigmented onions. In this case, the missing links for the enzyme chain were provided by the three complementary yellow breeding lines. Thus, when the large onions were crossed, the resulting variety took back what likely was its original color.

The complementary factor is regarded as a nuisance in most onion growing circles, particularly in the small, yellow cooking onion market, which is prevelant in New York. "The fresh market for onions, such as hamburgers, salsas and salads, is where the New York Sweet Blush has potential," Walters said.

The New York Sweet Blush is noticeably sweeter and more mild than many of its cousins. As a comparison, the New York Sweet Blush registers more sugar but less pyruvate -- the substance that makes it pungent -- than the popular Kelsae Sweet Giant. "Very few onions are as mild as the Kelsae Sweet Giant, and I've never seen anything as unique as the New York Sweet Blush. It's a real boon to the consumer, because when you see that pink blush, you know you're going to get a nice, mild onion."

For more information on obtaining test cultivars, contact Walters at (607) 255-2493.