Four diseases tend to hammer peanut  yield and quality in North Carolina with researchers at North Carolina State University conducting a  number of research trials to combat the problem.

During the 47^th annual meeting of the American Peanut Research and Education Society in Charleston, S.C. July 15, Wesley Hancock, a crop science graduate student at N.C. State presented a paper on the breeding programs at the university seeking resistant varieties to the diseases leaf spot, cylindrocladium black rot (CBR), sclerotinia blight  and tomato spotted wilt virus.

Corley Holbrook, left, supervisory research geneticist with USDA’s Agricultural Research Service in Tifton, Ga., discusses peanut research with David Langston, director of the Tidewater Research and Extension Center in Suffolk, Va., during the 47th annual meeting of the American Peanut Research and Education Society in Charleston, S.C. in mid-July.

“We’ve been working on breeding resistance to these diseases for a number of year and the release of cultivars with even partial resistance to these diseases would save area growers substantial sums in management costs and might result in greater yields as well as improved pod and seed quality,” Hancock said at the APRES meeting.

“Our basic strategy has been to cross the best agronomic lines with the best disease resistant lines and to select simultaneously for resistance to all four diseases in segregated generations,” Hancock said. “We observed net gains from all disease reactions and we made progress in breeding for improved disease resistance and our methods have resulted in high yielding disease resistant lines.”

Hancock explained that the databases of field reactions were subset to include data on any lines that were included in the trials for at least three years and tested since 2000 when tomato spotted wilt began bringing economic losses to growers in North Carolina.

“Genetic gain was observed for all disease reactions,” Hancock said.

For sclerotinia blight, selection has been effective, but the disease can have such a severe effect on yield and control is so costly, that efforts to breed for resistance must be increased, according to Hancock.

“Another disease that impacts farmers in North Carolina is CBR. Normal control of this includes soil fumigants which is costly and has to be applied in advance so breeding for disease resistance is definitely  needed,” Hancock said.

Varietal resistance for  tomato spotted wilt is also important because the disease can’t be controlled with chemical applications. “The main methods of disease management have been to increase plant populations, a costly method because of increased seed cost or to identify resistant cultivars. It is our goal to breed for increased host resistance to this disease,” Hancock said.