SCOTTSBLUFF, Neb. - (KNEP) - The Panhandle Extension Center is warning farmers of the presence of cercospora leaf spot or CLS in sugar beet fields.
CLS is caused by the airborne fungal pathogen Cercospora beticola, which overwinters in infected residue and can serve as an inoculum source the following season. Disease development is strongly dependent upon very specific environmental conditions, including periods of high humidity or extended leaf wetness (more than 11 hours) and warm temperatures (higher than 60 degrees Fahrenheit at night and 80-90 degrees F during the day). Without these conditions, disease spread and damage to beet crops is greatly reduced or inhibited.
On July 15th, the Extension Center found symptoms on lower leaves of sugar beets at their research plots which suggests the infection occurred before July 4th. Robert Harveson, an extension plant pathologist, states that is incredibly early for Western Nebraska. He added this implies other leaves may be infected but not showing symptoms yet.
Economic loss occurs in both tonnage and sugar content when the infection is present in newer, upper leaves.
If conditions are conducive, the disease can spread quickly. Harveson noted agriculturalists should be on the lookout. Fungicide applications may be necessary if it continues to rain and stay warmer at night.