Heavy late spring rains have triggered reports of sooty molds in wheat from eastern and central Kansas, according to Kansas State University plant pathologist Erick De Wolf.
"In most situations sooty molds are considered to be a cosmetic problem and will not result in any reduction in yield," said De Wolf, who specializes in wheat diseases for K-State Research and Extension.
"However, if wet weather persists, the fungi can begin to colonize the kernels, resulting in small dark lesions known as black point. Black point symptoms can reduce grain quality."
No management of sooty molds is possible or needed, he said. Fields with an abundance of sooty molds will make harvest operations a dirty job, because the black spores are disturbed and blown into the air by the combines. Individuals with severe mold allergies should take precautions to minimize exposure to the dust and spores produced during harvest.
Symptoms of sooty mold include a dark olive green or black fungal growth on the heads of mature wheat. The small mold patches are superficial and randomly distributed on the glumes, chaff and awns. The fungi that cause sooty molds are common. They specialize in the decomposition of plant debris and are often among the first to colonize the dead tissues of mature plants.
"Interestingly," De Wolf said, "the distribution of sooty molds can provide insights into other production problems that were previously unidentified. For example, when sooty mold is found in patches within a field it suggests that these plants matured earlier and have weathered longer than the other areas of the field. Clearly, many things can cause wheat to mature early including standing water, dry soil conditions, fertility problems, or diseases such as barley yellow dwarf. In many cases, plants that matured early will have smaller kernels. In most cases, however, the sooty mold was not responsible for the reductions in grain fill, but is simply an indicator of other earlier problems."