Goodbye Grape Seeds

After years in which the only seed-free grape available was the pale green Thompson Seedless, modern plant breeders have come up with half a dozen new varieties--and more are on the way. This is in part the result of a new lab method that accelerates the development of hybrid grape seedlings with the seedless trait.

First of the new grapes was the red Flame Seedless, introduced in the 1970's by the ARS lab in Fresno, California, and now grown worldwide. Flame's sweet, distinctive flavor made this crisp grape an instant hit, second in popularity only to the Thompson.

ARS Fresno researchers are understandably enthusiastic about a luscious new seedless named Black Emerald. These grapes, each about the size of a dime, are sweet, firm, and juicy, with an attractive dark black skin and are perfect for early summer snacking or salads.

Meanwhile, there are other seedless grapes that should be available now--or within a year or so. They include Autumn Seedless,Crimson Seedless, and Fantasy Seedless.

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Carrots: More Vitamin A

Carrots are an important source of fiber, bulk, and carotenes. Carrots are also loaded with a specific carotene--beta carotene--an antioxidant considered by many researchers as valuable to human health.

When ARS research began some 30 years ago, carrots contained only about 70 parts per million of carotene. Today most commercially grown carrots contain 120 to 160 parts per million, thanks in large part to the development of new carrot breeding lines by ARS researchers. Eating a single carrot today can satisfy 100-percent of the adult daily requirement for Vitamin A.

One new variety, A-Plus, a fine-flavored vegetable recommended for the home gardener, has nearly twice the carotene levels of earlier garden varieties. Even more carotenes are packed into another ARS-developed variety, Beta III, developed for commercial plantings. And the newest carrot, named simply HCM, has five times the carotene levels of most carrots grown today.

ARS carrot research has been carried out in cooperation with Wisconsin, Idaho, and Florida universities and with several seed companies.

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Softball-sized Lettuce

One of America's foremost lettuce breeders, 65-year-old Ed Ryder of Salinas, California, says he has eaten a lettuce salad every day 'since I was able to chew.' Ryder, an ARS geneticist, in 1975 introduced his now legendary Salinas variety of iceberg lettuce to growers. Among its virtues, it was able to make it to distant markets with far less crushing and bruising than other icebergs of its time. Since then, seed company breeders have produced new improved lettuces, all of them derived from Salinas. Ryder himself improved on his initial product in 1988 with Salinas 88, a variety with all the attributes of the famous parent plus resistance to mosaic virus disease. Today Salinas and its progeny are the most widely planted iceberg lettuces in the Salinas valley, the world's foremost lettuce-growing region. Salinas and its spinoffs bring about $300 million a year.

One of the newest offsprings of Salinas is a miniature iceberg lettuce the size of a softball. ARS researchers wanted to breed a full-flavored lettuce for single people who have trouble using up a whole head of lettuce while it is still fresh. The "Mini-green" lettuce, is as crisp and flavorful as its parent. It can be eaten by one or two people at a sitting.

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Hottest USDA Release

The hottest release (in more ways than one) of the U.S. Vegetable Lab in Charleston, South Carolina, is a cayenne pepper, which is ideal for the home gardener. Named Charleston Hot by the ARS and Clemson University researchers who developed it, the pepper is 20 times hotter than the typical cayenne. Charleston Hot is also more attractive; the pepper changes through a rainbow of colors as it ripens, an unusual trait for a cayenne. It starts out leaf green, changing to golden yellow, bright orange, and deep red when mature. One plant will produce up to 150 pepper pods, or about half a pound of dried peppers.

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Sweeter Onions Are Here

Hearty eaters who like a thick slice of mild raw onion on their hamburgers welcomed the appearance of Georgia's Vidalia onion--at least for a few months in spring and early summer. Now ARS and university breeders have come up with several new varieties that are sweet and mild. One is the Sweet Sandwich onion, suitable for home gardens in the northern states. It has been released by ARS and the agricultural experiment stations of Michigan and New York.

When one looks at the history of onion breeding, however, it's a good bet that Sweet Sandwich will someday be replaced by other improved varieties. ARS plant breeders have released more than 40 varieties and 63 inbred lines. An ARS breeder discovered the male-sterile system for producing hybrid onions that has been used by industry since the 1940's.

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Picking Good Cantaloupes

Growers assumed until now that a cantaloupe's sweetness was diluted by the excess water taken up by the roots. Not so, report scientists at ARS and North Carolina State and Arizona universities. They found that a cantaloupe will stay sweet if it is harvested within a day or two after a heavy rain. The objectionable bland flavor develops about four days after the rain, when roots shut down--stressed because they can't take up oxygen from water-saturated soil. Then they signal the leaves to stop manufacturing sugar. Meanwhile, the sugar in the cantaloupe starts breaking down. So after a deluge, say researchers, don't pick a melon on Day 4, 5, or 6.

An alternative for the grower who can't harvest his cantaloupes right away is to pick them at least a week after the rain, when the melon's sugar rebounds.

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No 'Pillows' in Cukes

The produce trade calls them 'pillowy'--those spongy white areas that sometimes occur inside cucumbers. Invisible from the outside, they ruin a cuke's crispness and flavor. In pickles, pillowing shows up as unsightly discoloration--an unacceptable condition for processors and consumers.

In 1987, the Claussen Pickle Company asked an ARS plant breeder in Madison, Wisconsin how it could reduce losses from pillowing. The breeder found that the condition occurred when the cukes were stressed from high temperatures and inadequate water, either from rain or irrigation. Cucumbers need calcium from the soil, and without enough water, they can't get it. The researcher also found that pillowing can occur or worsen when cucumbers are heat-stressed after harvest, even on the way from the field to the plant.  The breeder recommended hydrocooling cucumbers to 45^o F immediately after picking.

ARS and the University of Wisconsin also have developed cucumber lines with bright orange flesh. The color comes from the carotene, which can run as high as 25 parts per million. Flavor is unaffected. Unlike carrots, cucumbers grow well in the hot, humid climates of many Third World countries, and high-carotene varieties could help correct Vitamin A deficiencies in children.

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Orange with Mixed Parents

An exciting new hybrid from Orlando, Florida, is Ambersweet, with a parentage of one-half orange, three-eighths tangerine, and one-eighth grapefruit. Developed over 28 years by an ARS plant geneticist, the new orange is sweet and much easier to peel than other Florida oranges, which should make it popular as fresh fruit. But it also has a brightly colored juice that tastes like orange juice, and the Food and Drug Administration has okayed labeling its squeezings as such, despite the fruit's mixed parentage. Ambersweet trees, which are moderately cold hardy, have been widely planted in Florida and fruit is available commercially.

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Strawberries Year-Round

Ninety percent of strawberries marketed today are grown in California, Oregon and Florida, but the number of local pick-your-own farms, particularly close to cities, has grown steadily. One important reason for their success is research. While many highly skilled plant breeders work closely with the big commercial producers, ARS geneticists, including those at the Fruit Lab in Beltsville, Maryland, have also focused on helping small growers and home gardeners in the East and Midwest. They help them battle insect pests and the fungal diseases that are the scourge of berry growers. And they are breeding varieties that produce fruit longer.

Two of their most notable achievements are so-called everbearing strawberries, Tribute and Tristar, that bear fruit four months longer than conventional spring-fruiting varieties.

Three of the Fruit Lab's latest releases are Mohawk, Northeaster, and Delmarvel. In June, the plants produce firm, flavorful fruit suited both for shipping and local markets. Mohawk has been released jointly with Canadian scientists; the other two were released cooperatively with researchers at Ohio State University and Rutgers.

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Painless Blackberries

Picking blackberries without pain became possible in the eastern United States in 1966. That's the year that USDA plant breeders introduced the first truly genetic thornless blackberries. From these, geneticists developed several bigger and sweeter varieties, encouraging growers located from the mid-Atlantic to Midwestern states to add this new crop to pick-your-own farms and roadside berry markets.

Nearly all the blackberries that are frozen or made into jams and jellies are grown in Oregon. One variety, Marion, was released by USDA in 1956. Its flavor, juiciness, and yield have made it the most important blackberry variety in the world.

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Tons of Blueberries

Growing blueberries as a commercial crop had its origin 87 years ago, when a USDA botanist at Beltsville, Maryland, successfully crossbred several wild native plants to produce the first cultivated blueberry crop. Since then, ARS researchers, in cooperation with state and other federal researchers, have released more than 45 blueberry varieties.

U.S. growers supply the U.S. fresh market and processing demand and European and Asian markets. Blueberries are also exported to Europe and Asia.

One ARS variety--Bluecrop--common today on pick-your-own farms, has large berries that ripen through June. A new variety released in 1997, Chandler, will allow harvest through July and August.

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A Crop Full of Flavor

Chewing gum, mouthwash, juleps, toothpaste, and candy canes have an agricultural ingredient in common: mint. As a crop, it isn't in the same league as corn and soybeans, but in the Pacific Northwest and several other locations, it's a specialized cash crop for a number of farmers.

An ARS repository in Oregon's Willamette Valley (one of 30 ARS managed gene banks) contains some 500 different species and varieties of mint. Spearmints and peppermints are the most familiar, but there are many others, including white-edged pineapple mint, that can be used as an ornamental, and aromatic orange mint, chocolate mint, and a fragrant eau de cologne mint.

Mint harvesting in the Northwest begins in midsummer. Farmers cut the mint close to the ground and dry it in the field for several days. The mint is then steam-distilled to extract the oil, which is sold by the barrel to mint users like Colgate-Palmolive and Wrigley's. A pound of mint oil, says the Oregon Mint Commission, can flavor 45,000 sticks of gum.

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Pecans Getting Fatter

ARS geneticists are working to breed healthier, more productive pecan trees.  Since the breeding program began in the 1930's, the USDA researchers have released more than 15 new varieties.

Kernels of the improved breeds are longer, fatter, and more uniform than those of native pecans. Each nut is 60 percent edible kernel, compared to 45 percent for natives. New pecan varieties are also bred for disease resistance and high overall yields. Several of the newer USDA varieties bear twice as much as the natives.

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Better Hops, Better Beer

Most Americans have never seen or sniffed hops, which are cone-shaped clusters of dried flowers of the hop vine, grown mainly in the Pacific Northwest. But millions of beer drinkers know and appreciate their characteristic aroma and bitter flavor. Extract of hops is an essential ingredient of beer and ale.

In years past, the finest hops were a German-grown variety called Hallertauer mitteifrut. In recent years, however, fungal disease has all but wiped it out. Now ARS scientists in Corvallis, Oregon, have bred new varieties of U.S. hops with Old-World beer aroma and flavor. They were bred from the best German variety crossed with other European hops. Unlike their famous parents, the U.S. varieties are disease-resistant.

Two of the best new releases are Liberty and Mount Hood, which already are reducing the reliance of American brewers on imported hops. They are also popular with the growing number of local micro breweries, which typically use more hops to flavor their product than do the big brewers.

The mellow flavor of beer stems from its other chief ingredient, malted barley. An ARS research team in Madison, Wisconsin, is testing new barley breeding lines for qualities that will make good beer even better. The most important test is how much of a malt dissolves in hot water; brewers can't use malt that won't dissolve. A search is on for locations on barley chromosomes of genes that give rise to desired malting qualities.

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Rotten-Apple Fighters

An ARS-developed product (USPN 6,017,752; Docket #1155.87), Bio-Save, uses a naturally occurring microorganism to fight apple and pear fruit rot.  It is one of the first EPA registered biofungicides.  Psuedomonas syringae, a harmless bacteria found on apple surfaces, is the active ingredient in Bio-Save™.  The biofungicide prevents fruit infection by out-competing harmful pathogens on fruit surfaces, and protecting the wound so invading pathogens don’t have an opportunity to infect the fruit. More than 60 percent of winter pears in the Northwest are treated with Bio-Save™.

The natural active ingredient is an environmental alternative to methyl bromide and other chemical fungicides.  It is effective against multiple postharves diseases, which can cost growers, processors, and consumers millions of dollars annually in losses and retail costs. Bio-Save™ is a licensed product of Village Farms of Longwood, Florida.

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