Measuring Soybean Cyst Nematode Populations Using Remote Sensing.

The soybean cyst nematode (SCN) (Heterodera glycines) is an economically important pathogen of soybean (Glycine max [L.] Merrill) throughout the United States. This nematode caused annual losses of 152 million bushels in the United States during 1996-2012. Phenotypic characterization of genotypic resistance to SCN is labor intensive. Remote sensing technologies have the potential to characterize plant stress. These technologies may provide powerful tools for monitoring plant growth and development and for detecting plant disease caused by SCN in soybean. The objective of this study was to characterize differences in soybean cyst nematode (SCN) reproduction on soybean genotypes using remote sensing. The experiment was conducted at three locations in N.E. KS in 2012 and 2013. Two SCN resistance genotypes, KS5502N, KS5004N and two susceptible genotypes 5002T, 5601T were planted in a randomized complete block design with 10 replications. Initial and final SCN soil population densities and SCN root population were obtained. Canopy reflectance and temperature were measured from R1 (beginning flowering) through R6 (full seed) on sunny days. In 2012, wavelengths from 405-465 nm and 765 nm were positively and negatively correlated with reproductive factor (RF=Pf/Pi), respectively. However; there were no significant differences among genotypes for canopy temperature. Observations from 2013 will be compared with 2012 results.