By Jason Kelley, Wheat and Feed Grains Extension Agronomist
The sugarcane aphid has quickly become the most troublesome pest of grain sorghum in Arkansas since its arrival in the state in 2014. Producers have insecticide options for aphid control with Sivanto and Transform, but proper timing of insecticide treatments is made difficult by the rapid reproductive rate of the aphid and often uneven distribution in a field, making scouting more difficult. Even in our relatively small research plots, we have sometimes had a difficult time being timely with insecticide treatments when aphid levels rapidly increase, and yield loss from aphids is often the result.
Grain sorghum hybrids do differ in their tolerance to the sugarcane aphid. During the last two years, a large amount of work has been done in Arkansas evaluating sugarcane aphid-tolerant hybrids compared to our standard hybrids we have been growing. We have observed substantial differences in aphid numbers on plants and yield differences between tolerant and susceptible hybrids when aphids are not adequately controlled. For 2017, with slim profit margins, grain sorghum growers cannot afford to suffer yield losses from aphids. Grain sorghum growers should consider planting sugarcane aphid-tolerant hybrids this year to help reduce the risks from aphids.
The recommended list of sugarcane aphid-tolerant grain sorghum hybrids below is based on work conducted in Arkansas. These hybrids have demonstrated fair-to-good aphid tolerance and have good yield potential and sound agronomic characteristics under our growing conditions. Note that none of the hybrids are rated as having “excellent” tolerance. Sugarcane aphids are capable of infesting these hybrids and causing yield loss, and still need to be scouted and treated when thresholds are reached. However, these hybrids will slow the aphids down, and offer a level of risk reduction that is needed to help produce a profitable crop.
|Recommended Grain Sorghum Hybrids with Confirmed Sugarcane Aphid Tolerance Evaluated by the University of Arkansas and Commercially Available in 2017*.|
|Years Tested by U of Arkansas||Aphid Tolerance Level||
|Dekalb||DKS 37-07||2006-07, 2015-16||Good||Med-Early|
*Hybrids reported as tolerant to sugarcane aphid can still have high numbers of aphids and will likely still need insecticide treatment to control aphids.
Additional sources of Grain Sorghum information:
Arkansas Grain Sorghum Production Handbook, MP 297: http://www.uaex.edu/publications/pdf/mp297/MP297.pdf
Arkansas Grain Sorghum Quick Fact Sheet: http://www.uaex.edu/farm-ranch/crops-commercial-horticulture/grain-sorghum/2017%20Arkansas%20Grain%20Sorghum%20Quick%20Facts.pdf
Arkansas Grain Sorghum Hybrid Testing Results: www.ArkansasVarietyTesting.com
Sugarcane Aphid, a New Pest of Grain Sorghum in Arkansas: http://www.uaex.edu/publications/FSA-7087.pdf
Please contact me by email at firstname.lastname@example.org, if you have questions or comments regarding this newsletter. This article and other timely articles on Arkansas crops can be found at: www.arkansascrops.com