Sugarbeet Growers in Epic Battle with their Nemesis, Cercospora Beticola (09/15/16)
Sugarbeet Growers in Epic Battle with their Nemesis, Cercospora Beticola
Early planting and favorable growing conditions resulted in early row closure and the potential for a high yielding sugarbeet crop. The environmental conditions were also favorable for early infection and rapid development of a high population of overwintering Cercospora beticola, the causal agent for Cercospora leaf spot (CLS). Nearly all sugarbeet fields have some level of CLS. Fields with high CLS disease severity and with disease starting earlier in the season will have lower tonnage and reduced sugar concentration compared to healthy plants.
Most growers have done a phenomenal job of making timely fungicide applications and keeping their fields green with minimal leaf loss (Fig. 1). Because of wet conditions compounded with fungicide resistance issues, Cercospora leaf spot was not adequately controlled in some fields resulting in leaves becoming brown and necrotic (Fig. 2). Growers should continue to protect fields with healthy leaves using fungicides until September 15. Fungicides such as TPTH (7 day Pre-harvest interval –[PHI]), Proline (7 day PHI), Headline (7 day PHI), Eminent/Minerva (14 day PHI), EBDC fungicides such as Mancozeb, Manzate, and Pencozeb (7 day PHI) may be used depending on which fungicides were used earlier in the season. Consult your agriculturists, County Agents, consultants or me if you need assistance to determine which fungicides to use, keeping in mind that the full campaign starts on October 1. Have a safe and bountiful harvest.
Extension Sugarbeet Specialist
NDSU & U of MN