PAUL, Idaho—Raising sugarbeets has changed tremendously in the last 10 or 15 years thanks largely to technology.
In the old days, many beet plants were infected with curly top, a virus that is transmitted by leafhoppers. But thanks to plant breeders who have incorporated resistance into new varieties, the virus – while still present – is not as economically devastating as it once was.
Today soil-borne diseases are becoming more prevalent as growers shorten crop rotations and increasingly rely on center pivots to irrigate crops. Oliver Neher is seeing more rhizoctonia and aphanomyces, diseases that can significantly reduce the sugar content in the beets depending on how early the root was infected. Neher is a plant pathologist with grower-owned Amalgamated Sugar Co.
Signs of rhizoctonia are similar to aphanomyces but if the grower can scratch away a black scar on the beet with a finger nail, the problem is aphanomyces. Beets that have an unusual number of root hairs are likely infected with rhizoctonia.
A shallow water table or compaction favor development of fungal root diseases, although environmental conditions will exacerbate the problem. Plants under stress are more susceptible to other diseases, Neher said.
One of those potential problems is cercospora leaf spot. The disease has long been the bane of growers in North Dakota and Minnesota where hot temperatures and high humidity favor the disease. Southern Idaho experienced an outbreak in 2013, but hasn’t seen much pressure since.
However, as more beets are grown under center pivots, the potential for an outbreak increases.
“Each time you turn a pivot on, you create favorable conditions for blight,” Neher told growers during a research field day held by Amalgamated.
Source: www.thepublicopinion.com