Issue link: http://read.dmtmag.com/i/132109
VAPOR GARD ® Photo By freD Miller FOR CHERRIES AND APPLES No Generic Substitute! Much of the fame of the University of Arkansas fruit breeding program came from work with blackberries, and Arkansas varieties are grown world-wide. Here John Clark looks over a promising trial variety being grown in California. A CONSISTENT PERFORMER ROSBREED work opens doors T he new world of fruit breeding is challenging, says Dr. John Clark, University of Arkansas breeder of peaches, grapes, and blackberries. Now in his fifties, Clark said his generation of fruit breeders were usually phenotypers; they worked by selecting for traits that were visible or measurable. But the new breeders are also often genotypers, with training in molecular biology. "Those trained in this area don't have to see a plant or a fruit to know a trait is there," he said. "They find markers associated with a trait, and they can determine whether a plant carries that trait without waiting years to test the fruit." Clark said his own work as a breeder did not depend on adopting this new technology, but the future of his breeding program did. "I thought, 'why bite off all this new stuff?'" he said. "But when RosBREED came along, it sounded like something worthwhile, and led to my involvement." The approach Clark adopted is to mentor promising students, who he calls "breeder trainees," who take on projects. One of his students, Paul Sandefur, will soon publish a paper outlining the genetics determining the storability of peaches. He developed a protocol that was used on the three new varieties released last fall. Another student, Alejandra Salgado, is attempting to find markers associated with different flesh types in peaches. The five types are melting, slow-melting, nonmelting, stony hard, and nonsoftening, although the stony-hard source is probably not present in the Arkansas program, Clark said. Breeders work with many traits in peaches—fuzziness, shape, size, acidity, color, sweetness, flavor, and others. One current trend is to emphasize sweetness, and Clark thinks breeders will push peach sweetness from 12-14 degrees Brix to 20 or more. —R. Lehnert The Arkansas peach and nectarine cultivars are by Cumberland Valley Nurseries, Inc., in McMinnville, Tennessee. Clark would welcome other propagators and hopes Arkansas-bred varieties will be tested and used in the Midwest, East, and Southeast, or even in the West. Laying the groundwork John Clark gives credit to his predecessors for laying the groundwork for his program, which has released several new peaches and nectarines since 2000. When the program began in 1964, breeder Jim Moore focused on developing cling peaches growers could sell for processing to the Gerber baby food plant at Ft. Smith, Arkansas. Fred Hough, then the peach breeder at Rutgers University in New Jersey, provided germplasm in a low-acid white peach that turned out to carry genes for a unique kind of firmness, and that formed the basis for much of the breeding since, Clark said. When Gerber quit purchasing Arkansas-grown processing peaches, the breeding program's emphasis shifted in the fresh-market direction, he said, but the firmness genes remained. Clark began releasing fresh-market peach varieties in 2002, coming out that year with White River, a large, sweet peach. It softens at ripening like other melting-flesh peaches. In 2004, he released White Rock and White County, the first low-acid white cultivars. "White Rock appears to have two sources of firmness, one the processing cling type, and the other a unique type introduced in the program in the 1980s," Clark said. "These sources appear to be possibly additive, providing for an exceptionally firm fruit that does not soften until fully ripe," he said. Three nectarines also came from the Arkansas program, one melting flesh and two nonmelting. The very early ripening Westbrook, a melting variety, was released as a localmarket nectarine with good flavor but lacking firmness for shipping. Westbrook is among the most bacterial-spot-resistant genotypes in the program, Clark said. Arrington and Bradley nectarines both have nonmelting flesh. Flavor is a processing peach/nectarine mix, he said, and both hang well on the tree and allow for ripe fruits to be harvested and handled. • www.goodfruit.com # ! $ ! " I like to use Vapor Gard on club and specialty varieties of apples to reduce sunburn. Growers like to apply Vapor Gard starting at the beginning of the sunburn season. Vapor Gard is consistent and always works well. $ "We used Vapor Gard on cherries every year it was needed for cracking prevention. I used it before rain and it seemed they didn't split as bad. We'd normally used it a couple times a year. I was always happy with Vapor Gard. I wouldn't grow cherries without it." $ # I have used Vapor Gard for years for rain protection with great results. No shipping restrictions and greener stems are a great plus. I see that my cherries stay firmer longer with Vapor Gard. Vapor Gard has more benefits than just rain protection." CONFIDENCE Comes from 40 years and over 150,000 acres treated with VAPOR GARD. That's why many Growers, Consultants, Pest Control Advisors and Packing Houses understand VAPOR GARD's BENEFITS and VALUE on CHERRIES. VAPOR GARD on cherries offers growers these benefits: ®INCREASED SIZE & YIELD ®REDUCED SPLITTING Using (with early application) (from untimely rain) ®INCREASED SHELF LIFE (greener stems) MILLER CHEMICAL & FERTILIZER CORP. 800-233-2040 SEE LABEL FOR ADDITIONAL INFORMATION AND ALWAYS READ AND FOLLOW LABEL DIRECTIONS GOOD FRUIT GROWER June 2013 31