Wheat Seed Quality Questionable

August 11, 2004

WOOSTER, Ohio — Growers who save seed from their wheat harvest for the following season's planting should probably seek other seed sources for producing next year's crop.

 

Pat Lipps, an Ohio State University Extension plant pathologist with the Ohio Agricultural Research and Development Center, said that seed quality is an issue this year, mainly due to the late development of Fusarium head scab caused by excessively wet weather during the crop's flowering period through harvest.

"Incidence of head scab, on a statewide average, was around 13 percent. A moderate low level, but the late scab development didn't correlate well with the earlier disease levels. In other words, seed infection and vomitoxin were higher that what we expected for the level of disease we had in the field," said Lipps. "Because of the wet weather the fungus continued to colonize the grain and produce toxin."

Lipps said vomitoxin levels, where detected, ranged anywhere from 2 parts per million to 5 parts per million. Grain elevators may turn away grain with levels of vomitoxin 2 parts per million or higher.

"Germination tests from seed companies are reporting high levels of seed infections, even in seed that looks normal," said Lipps. "Test weights of 58 pounds or better usually indicate good quality seed, but we've had grain that's 60 pounds or higher that is heavily infected. So we are telling growers to just don't trust any of it."

Ohio State Extension specialists are recommending that growers who do not have adequate facilities to clean, store and treat seed should not save their seed for next year.

"What growers have to do is clean the grain, remove all the shriveled kernels and treat that grain with a good seed treatment material," said Lipps. "Air cleaning will not be sufficient to remove all diseased seed, but a gravity table will do a much better job if set to clean out sufficient light weight seed. Several seed processors have reported that they are discarding about 20 percent of the grain during the cleaning process to improve seed quality."

In addition to treating seed for head scab, growers should also clean and treat seed for Stagnospora glume blotch. Both diseases can cause germination and stand problems in plants if infected seed is planted.

"What will happen is if you plant that seed you may get a seedling blight which will either reduce stands or the plants will stay alive until winter. Then they'll die out over winter and the stands will decrease in the spring," said Lipps.

Lastly, all seed should be tested for germination before planting.

"A germination test is an indication of the level of possible problems that may arise from using poor quality seed and using poor quality seed can be reflected in the yield of the crop," said Lipps.

Seed with germination percentages below 80 percent should not be planted.

Author(s): 
Candace Pollock
Source(s): 
Pat Lipps, Peter Thomison, Valente Alvarez