Distribution and Abundance of Heterodera glycines and Macrophomina phaseolina in Ohio

Lopez-Nicora, H. D., Simon, A. C. M., Dossman, B. C., Paul, P. A., Dorrance, A. E., Lindsey, L. E., and Niblack, T. L. 2015. Distribution and abundance of Heterodera glycines and Macrophomina phaseolina in Ohio. Plant Health Prog. 17:35-41. Soybean and corn are grown on more than 60% of the arable land in Ohio. The soybean cyst nematode (SCN) is responsible for significant losses incurred by soybean growers every year. The fungus that causes charcoal rot, Macrophomina phaseolina, causes significant yield loss in soybeans worldwide and can also affect corn. Both organisms are soilborne pathogens. The objective of this study was to determine the presence, distribution, and abundance of both SCN and M. phaseolina in soybean and corn fields across Ohio. During 2013 and 2014, composite soil samples were collected from 370 corn and soybean fields. Samples were processed for SCN eggs/100 cm and M. phaseolina colony forming units (CFU)/g soil with standard techniques. Results from this study revealed a widespread distribution of SCN and M. phaseolina in both soybean and corn fields. This study represents the first survey on the distribution of M. phaseolina in Ohio and the findings will be used to educate producers on the potential risks posed by both SCN and M. phaseolina.