Description

Anthracnose is a seed-borne disease caused by the fungus, Colletotrichum lindemuthianum, which affects all foliar components of dry bean plants, including the underside of the leaf, stems, and petioles (Río and Bradley, 2002). When contaminated seeds are planted, entire fields can be lost or unmarketable, depending on the level of inoculum present in the harvested seed (Gillard et al., 2012; Melotto et al., 2000). Prevention is the best way to manage this disease.

The most important management tool available to growers is the use of certified, anthracnose-free seed. C. lindemuthianum in dry bean seed is regulated by the North Dakota State Seed Department (NDSSD) where a zero-tolerance policy for anthracnose is enforced, and therefore, any anthracnose detected results in seed lot rejection for certification. In 2002, the NDSSD introduced the standard, requiring that seed grown in North Dakota must be tested for anthracnose if there are plans to commercially sell certified seed in the state.

NAGC, in collaboration with the NDSSD, has developed a quantitative PCR test for detection of anthracnose in dry edible beans. This assay not only provides more sensitive measures of disease detection for the seed certification program, but also can potentially help North Dakota seed producers build up a market for their seed, which is currently dominated by western grown seed that claims to be disease free.

This project was funded by the North Dakota Department of Agriculture Specialty Crop Block Grant

References

Gillard, C. L., Ranatunga, N. K. & Conner, R. L. 2012. The control of dry bean anthracnose through seed treatment and the correct application timing of foliar fungicides. Crop Protection, 37, 81-90.

Melotto, M., Balardin, R. & Kelly, J. 2000. Host-pathogen interaction and variability of Colletotrichum lindemuthianum.

Río, L. T. d. & Bradley, C. A. 2002. Anthracnose of dry beans. NDSu Extension Circular.