This research also indicates that planting peanut at high plant populations and in narrow rows does not offer any advantages from a yield standpoint compared with traditional seeding rates and row spacings when pests are adequately controlled and the variety NC 10C is planted. Historically, CBR was more important in North Carolina than in Virginia and Sclerotinia was more important in Virginia than in North Carolina. Over the past several years, CBR has spread north into Virginia and Sclerotinia south into North Carolina, so peanuts in both states now suffer from both diseases. Both diseases are soil-borne, occurring in patches in infested fields, and both produce survival bodies that can persist for years in the soil, making crop rotation less effective in managing the diseases. Fungicides are labeled for both diseases, but they are not particularly consistent in the degree of control provided.
Resistant cultivars are an important part of the grower's program of disease management.
However, there have not been any cultivars with high levels of resistance to either disease. The peanut breeding project at NCSU has adopted development of multiply disease-resistant cultivars as its top priority on behalf of growers. For CBR, an accelerated breeding program augmented by a winter nursery has been in use for ten years. This program is the source of resistant breeding line N93112C among others. The steps in this program are outlined in detail in this year's proposal.