Likelihood of Soybean Cyst Nematode Reproduction on Henbit Roots in Nebraska.

Soybean cyst nematode (SCN; ; Heterodera glycines Ichinohe) is a major soybean yield-limiting disease in the United States. Henbit (Lamium amplexicaule L.), a winter annual species common to no-till fields in the Midwestern United States, is known to act as an alternative host for SCN. A simulation was performed to estimate how likely SCN was to reproduce on henbit roots during a 30 year period in two important soybean production areas of Nebraska. Simulations were conducted using published information on henbit seedling emergence, SCN reproduction on henbit roots, and SCN response to soil temperature. Results indicate that SCN would be able to complete one generation on henbit roots under Nebraska conditions. The SCN reproductive cycle was not likely to be completed before the winter in south central Nebraska, but one SCN generation was predicted to be completed in the fall in 2 out of 30 simulation years (7% likelihood) in southeast Nebraska. Based on our predictions, to reduce the chances of SCN population build-up in the absence of its main host (soybeans), weed management in fields infested with both henbit and SCN should be completed after crop harvest in the fall when most henbit seedlings have emerged and are growing but the SCN developing on henbit roots have not yet achieved full maturity in Nebraska.