Root disease incidence and severity have increased greatly in the last 15 years for Aphanomyces, Rhizomania, Rhizoctonia and Fusarium. Rhizomania was first identified in 1997 and by 2005 was present in nearly every RRV field. Fusarium was first identified about 1996 and is severe in the Moorhead district. It has spread to all other factory districts at this time. Aphanomyces and Rhizoctonia severity is increasing too.
American Crystal agriculturists have rated each township in our growing area for severity of each of the four major root rot diseases. Diseases were rated as none, slight, moderate or severe. Figure 1 is a map of Fusarium severity in the southern RRV. Figure 2 is a map of Rhizoctonia severity in the northern RRV.
Contact Your Agriculturist for variety performance experiences in your local area and disease rating maps.
Combining the information available from disease maps and variety disease rating data should result in best variety selection and more on-farm profit.
Choose varieties coded green for moderate to severe disease, black coded ratings for slight to moderate disease, and red coded disease ratings if no disease is present in the field.
Zone Fertility Management has increased profit by more than $50 per acre compared to conventional soil sampling and fertilizer application.
Be sure to check with your seed supplier regarding insecticide treatment availability or use granular insecticide for root maggot management in 2011.