Brent Loy, emeritus professor of plant biology and genetics at the University of New Hampshire has spent more than 45 years developing new melon, squash, pumpkin and gourd varieties. Among his 65-plus contributions licensed to seed companies by the university are early maturing cantaloupes, white pumpkins, and spineless (harvester-friendly) yellow summer squash.

Why are these new varieties created? “Often, it is to solve a problem,” Loy said. In cucurbits, powdery mildew and insects (especially vine borers, squash bugs and striped cucumber beetles) are among the biggest problems. “Other times it is for the challenge and the pleasure of discovery,” he added.

Whether developing a more compact, easier to cultivate squash or one repugnant to insects, Loy focuses on eating quality, nutrition, yield and market potential. His research is within the realm of traditional plant breeding, using what is known of plants’ genes to select for desirable traits, making crosses, and then selecting the best combinations.

“The genetics of jack-o’-lantern pumpkins are pretty amazing,” said Dr. Brent Loy. White and orange crosses combine to form different color combinations.


Striped pumpkins

Ornamental pumpkins are only a small fraction of the 1.13 billion pounds of pumpkins produced in the U.S. in 2013, but they have become a major source of fall revenue for growers who supply retail outlets or have farmstands or pick-your-own operations. For those markets—generally peaking at Halloween but also providing décor for Thanksgiving, weddings and other fall events—Loy has developed both white and yellow pumpkins.

He’s currently working on an ornamental pumpkin with specific striping patterns. “The genetics of striping are very complex. I search for genes that cause the wanted variation and then cross breed,” he explained. For striped ornamental pumpkins, Loy began with the tiny striped Goblin Egg Gourd and crossed it with various jack-o’-lantern type pumpkins that also have many genes in their color pattern.

Like his other recently introduced pumpkins, the striped pumpkins will be semi-bush hybrids, which can be closely spaced to facilitate weed control through cultivation and are tolerant of powdery mildew disease.

Interspecies hybrids

Crossing cultigens of two of the three major squash species—acorn, kabocha and butternut—produces an interspecies, or interspecific, hybrid. Loy is developing vigorous growing, high-yielding interspecies hybrids by crossing selected breeding lines of Cucurbita maxima (a buttercup/kabocha species) with breeding lines of C. moschata (a butternut type). “Even with a big fruit load, they have incredible innate pest resistance,” Loy noted. These hybrids, which are being developed for both the fresh and processing markets, are sterile, and thus require a pollinator strain in order to set fruit.

Because of their resistance to soilborne diseases, interspecies hybrids are used throughout the world as rootstocks for grafting to melon and watermelon. Interspecies hybrid squash are tolerant to vine borer and powdery mildew. In addition, squash bugs are not a concern, as they prefer acorn, kabocha, summer squash and pumpkin.

Dr. Brent Loy holds a high-yielding relative of butternut squash he developed for pie processing. Most pie pumpkins for processing are grown in Illinois.

From breeding to market

“Plant breeding is a long-term process,” Loy stated. Seeds for the varieties he introduces may follow different paths on their way to market. Most start out through breeding for desirable horticultural characteristics that are preferred by growers and consumers. Mutant plants possessing a desirable trait are sometimes discovered in the field, but this is rare.

Loy stays abreast of market opportunities through contact with growers, seed companies, and from his observations of customer preferences at roadside markets and at a garden center that markets jack-o’-lanterns and other ornamental pumpkins he and his wife grow at home.

Several generations of genetically uniform breeding lines are grown and then crossed to produce hybrids, which are tested in several regions of the U.S. before being marketed by seed companies. In some instances, Loy may provide one parent of the hybrid plant’s genetics and a seed company may provide the other.

As one of the few “public” breeders of pumpkins and squash in the U.S. (i.e., not affiliated with a specific seed company), Loy may disseminate the products of his research, including his 20–plus varieties of ornamental pumpkins, to one or many seed companies. Loy is pleased to be able to share his findings, and it is a point of honor that he has never patented a trait he discovered. Although he prefers not to give any one seed company exclusive rights to new varieties within a particular breeding program, funding opportunities sometimes require such arrangements.

Seed companies offer the varieties Loy and other plant breeders develop both retail and wholesale. Thus companies like Johnny’s Selected Seeds and Rupp Seeds may develop some varieties and purchase others.

A handful of ornamental egg gourds: Striped egg gourds are being used in the development of a specifically striped jack-o’-lantern.

A history of contributions

The striped pumpkins and interspecies hybrid squashes Loy is developing continue the long line of his contributions to the world of cucurbits. Among his first, and perhaps best known, introductions are melons designed to be grown in the Northeast. Loy said, “For several years, ‘Earligold’ and ‘Earliqueen’ cantaloupe were the standard throughout much of New England.” They have since been replaced by ‘EarliChamp’ and ‘Halona’, two of Loy’s varieties that are resistant to fusarium wilt and powdery mildew. Most of the early cold-area cantaloupe varieties now grown in the Northeast—more than 20 varieties—were developed by Loy.

Loy considers a glabrous (smooth) stemmed yellow summer squash one of his biggest introductions. In 1992, Loy discovered a glabrous gene, which decreases the prickly spines (trichomes) on stems and petioles, in a mutant yellow summer squash. Fewer prickly spines mean less damage to the fruit and to workers’ hands. Slick Pik YS 26, the first glabrous yellow summer squash from his research, was introduced in 2009. Since then, and in response to market requests, Loy is making more cylindrically shaped, more plump summer squashes. Slated for production in 2015 is a powdery mildew-resistant glabrous summer squash.

Even warty pumpkins may find a market.

Ornamental pumpkins have gained popularity in recent years. In three fall 2014 seed catalogs Loy counted 150 varieties. Among them are several hybrids containing one or both parents he developed: ‘Trickster’, ‘Orange Smoothie’, ‘Racer’, ‘Neon’, ‘Hybrid Pam’, ‘Pik-a-Pie’, ‘Gold Standard’, ‘Gold Medal’, ‘Gold Challenger’, ‘20 Karat Gold’, ‘Hannibal’, ‘Chucky’, ‘Cider Jack’, ‘Champion’ and ‘Prankster.” All are semi-bush hybrids. In addition, Loy’s ornamental pumpkins have stems so strong that a 30-pound pumpkin can be carried by its handle.

In fall 2009, Loy introduced an 8- to 12-pound white pumpkin that was developed in response to market demand. Related to kabocha squash, ‘Moonshine’ is a semi-bush variety with a long, robust handle. “The genetics of white pumpkin pigmentation and strong fruit stems are fairly complex,” he noted.

Loy is working on developing a white pumpkin for areas that have an early season. “In the next few years, white pumpkins will have a huge impact on the market, especially in New England,” he said.

Since developing ‘Moonshine’, Loy has introduced two unique yellow pumpkins, ‘Owls Eye’ (marketed by High Mowing Organic Seeds) and ‘Sunlight’. He said, “Yellow pumpkins look great displayed next to white ones.”

Squash varieties that Loy considers among his best are ‘Honey Bear’ and ‘Sugar Dumpling’, both acorn-type squashes. Eating quality is very important to Loy, and he considers the development of improved squash varieties of superb eating quality among his areas of expertise. “I only wish that squash varieties would sell as well as the ornamental pumpkins I’ve developed,” Loy said.

White pumpkins are most attractive when coupled with orange or yellow ones. Loy carries both by large handles, which will not shrivel as the fruit matures.

Lots of seeds

Of all the cucurbit varieties Loy has introduced, he considers his most challenging and biggest breeding accomplishment to be hull-less snack seed pumpkins. The relatively thin-walled, seed-laden pumpkins are perfect for the snack seed and trail mix markets. Huge seeds with an edible coating resembling rice paper are delicious raw or roasted. Unlike traditional hulled pumpkin seeds, Loy’s hull-less seed coats require no processing or spitting. ‘Snackjack’ and ‘Snackface’ were introduced in the 1990s, but both are currently out of production. Replacement varieties with powdery mildew tolerance and better resistance to fruit rot diseases have since been developed. Loy believes hull-less snack seeds have great potential and hopes that the replacement varieties will soon be introduced.