A Prize Pinto, a Better Bean
A closeup look at Burke, the latest pinto bean from ARS and university plant
scientists. It resists a host of harmful fungi and viruses that can otherwise
cheat growers of a bountiful harvest.
When it comes to survival, Burke is a real scrapper.
The latest pinto bean cultivar from Agricultural Research Service and
Washington State University (WSU) scientists, Burke fends off several harmful
viruses and fungi that can fell a lesser plant.
Scientists bred the cultivar with a potent genetic package conferring high
levels of disease resistance. This should give commercial growers added
insurance against culprits like the bean common mosaic virus and bean common
necrosis virus. Both can cause yield losses of up to 60 percent.
A third menace, the curly top virus, is "a regional problem--mainly in
the Pacific Northwest, where seed stock is produced," says Phillip N.
Miklas, a geneticist in ARS' Vegetable and Forage Crops Production Research
Unit at Prosser, Washington.
He is part of a bean-breeding team that includes ARS plant pathologists Matt
J. Silbernagel and J. Rennie Stavely and WSU colleague An N. Hang. Their prized
pinto debuts this summer for production in western states including Colorado,
Idaho, Washington, and Wyoming.
Besides viruses, the new cultivar also resists U.S. forms of the rust
fungus, Uromyces appendiculatus. Unchecked by chemical fungicide or
other measures, Uromyces causes a rust-colored blight on the leaves of
susceptible bean plants. Severe outbreaks may wipe out an entire crop. But with
Burke, the fungus never gains a firm toehold in the rest of the plant, so it
doesn't cause serious disease.
The cultivar also withstands Pythium and Fusarium fungi,
soil-dwelling microbes that can inflict costly root rots.
"When conditions are ripe for root rot, you can have 20 to 30 percent
yield losses," notes Miklas. "Burke has a thriving network of roots
that allows it to survive damage caused by the fungi."
Farmers planting the hardy cultivar will get semi-upright plants that mature
in 89 to 95 days. Burke produces large, firm, tan-colored seeds that cook and
store nicely without turning into a crumbly, unappealing mush. That's
important, considering how fond American consumers are of pinto beans--eating
more than 3 pounds per person each year, according to USDA's Economic Research
While firm, high-quality seed is important to a cultivar's success, so is
high yield. Burke seems to measure up on both counts. In test plantings at 40
different locations in the Midwest and Northwest from 1994 to 1996, Burke
outperformed 8 competing pinto lines in the National Dry Bean Cooperative
In Colorado test plots, Burke's yields were up to 12 percent higher than the
industry standards, Othello and Sierra.
One likely reason: Burke is a cross between these two venerable cultivars,
so it possesses many of the desirable features of both, says Silbernagel. Now
retired, he and Hang did the original breeding work that led to Burke.
"Othello is one of the most widely grown pinto beans because it
performs well under many different growing conditions," says Miklas, who
is Silbernagel's successor. "An advantage of Burke over Othello is better
The new pinto line also earned higher ratings for canning quality in tests
conducted by ARS' George Hosfield at Michigan State University. Encouraged by
test results, Miklas' group applied for plant variety protection on Burke. This
will help ensure the cultivar's genetic purity and longevity as it goes into
commercial production.--By Jan Suszkiw,
Agricultural Research Service Information Staff.
Phillip N. Miklas and Matt J.
Silbernagel (retired) can be reached at the USDA-ARS Vegetable and Forage Crops
Production Research Unit, 24106 North Bunn Rd., Prosser, WA 99350; phone (509)
786-9258, fax (509) 786-9277.
"A Prize Pinto, a Better Bean" was published in the July
1998 issue of Agricultural Research magazine. Click here to see this
issue's table of contents.