Grain Sorghum Aphid Resistance

A number of Mississippi soybean producers also grow grain sorghum. In recent years, the sugarcane aphid (SCA) has become a major pest of this crop and has and will continue to cause significant damage to this crop in the Midsouth.

In my opinion, the surest and most dependable way to thwart any crop pest is to either develop or identify host plant resistance to that pest. This has been successful against soybean pests such as stem canker and cyst nematode.

It appears there may be some help against the SCA with this approach. The LSU Agcenter has released a guide that lists several grain sorghum hybrids that offer some level of resistance to the SCA. The listed hybrids have been tested in OVT trials at several locations in the state.

There are two levels of presentation in the guide. They are:

  • Yields of hybrids grown in LSU OVT tests that have confirmed resistance; and
  • SCA resistance screens with yields of hybrids that were both untreated and treated for SCA

The authors of this guide state that even though the listed resistant hybrids offer some protection against the SCA, it is possible that large populations can still develop on them. Therefore, producers must still pay close attention to all grain sorghum hybrids that are grown to determine if an insecticide such as Sivanto (flupyradifurone, Group 4D) or Transform (sulfoxaflor, Group 4C–check for approved registration label) should still be applied.

Drs. Catchot, Gore, and Cook of MSU have posted an article that discusses the SCA in depth and provides management guidelines. The Sorghum Checkoff has published a guide with links to additional information about SCA management and control. Texas A&M University also has a guide that can be consulted for SCA management information.

Seven of the grain sorghum hybrids (Alta Seeds AG1203; Mycogen 1G855C; Pioneer 83P17; Sorghum Partners SP7715, SPX17414, SPX 17514; Terral Seed REV 9782) identified as resistant to SCA in the LSU guide were grown at the three locations of the 2015 Mississippi Grain Sorghum Hybrid Trials. Yield of six of those seven exceeded the overall average yield in the trials. Thus, they apparently are good agronomic types as well as resistant to SCA.

Composed by Larry G. Heatherly, Feb. 2016, larryheatherly@bellsouth.net