In a recent study out of Iowa State University, researchers are finding increased Soybean Cyst Nematode (SCN) production in plants with low to moderate levels of Soybean Aphids. Early indications from this study show a 33% increase in egg and female SCN levels than on aphid free plants. This increase of females and cysts is found even on SCN resistant varieties.
The increased productions of SCN eggs and females from the added pressure of Soybean Aphid feeding can lessen the SCN resistance levels in the plants. This reduction of SCN resistance in the plant coupled with the increased Cyst and female production levels can overwhelm the plant and further reduce yields as well as increase the likelihood of having resistant Nematodes.
When I come across information like this it reminds me of the very quotable Winfield Solutions Agronomist Bob Schoper saying “remember, always bet on the pest”. Insects much like other predators when looking for its prey are looking for the easiest or best energy source to consume.
As an Agronomist and having the phrase “remember, always bet on the pest” fresh in my mind, I will be actively recommending to producers with a history of Soybean Cyst Nematodes in fields, stronger control methods such as seed treatments that help control Soybean Cyst Nematodes. In those SCN affected fields I may also be looking at stepping up Soybean Aphid control with earlier control measures that include multiple applications as well as multiple sites/modes of action.
