By Emily Unglesbee
DTN Staff Reporter
ROCKVILLE, Md. (DTN) -- After five years in sorghum fields, the sugarcane aphid is firmly established as a permanent pest of this crop.
Fortunately, Southern entomologists have spent nearly that long hunting down sorghum hybrids that show varying levels of resistance to the pest.
A fairly comprehensive and updated list has been posted by Texas A&M AgriLife Extension. Find it here: http://bit.ly/….
Some things to remember:
NO HYBRID IS PERFECT
As the Texas A&M entomologists are quick to point out, no hybrid shows absolute resistance to the sugarcane aphid.
In fact, some of the entomologists shy away from the word "resistance" and prefer "tolerance," which more accurately describes how the plant deals with the aphid.
So keep in mind that these hybrids are not immune to the aphid, and growers still must scout and monitor them for infestations.
That said, resistant or tolerant hybrids show significantly less damage from the sugarcane aphid, largely because populations build much more slowly on these hybrids, the entomologists explained. They can also better tolerate higher populations than a susceptible hybrid.
TAILOR THE SPRAYING THRESHOLD
With hybrids that show good tolerance of the aphid, growers can adjust the aphid spraying threshold upward from the standard 50-aphids-per-plant level, the entomologists said.
See a chart of the adjusted standards for resistant or tolerant hybrids here: http://bit.ly/….
ADD OTHER CONTROL OPTIONS
Don't depend on genetic resistance alone -- there are a host of ways to protect a sorghum crop from the aphid.
Planting early can ensure that sorghum plants are more mature and resilient when the aphid comes calling, the entomologists noted.
In addition to foliar sprays during the season, the Texas A&M entomologists also recommend an insecticide seed treatment, which can provide control of the aphid for around 30 days.
As for foliar sprays, most growers will have access to two insecticides: Bayer's Sivanto and Dow's Transform insecticide, which was granted a Section 18 emergency use exemption for sorghum in Texas, Louisiana, Mississippi and Alabama.
Arkansas, Georgia, South Carolina and Virginia and still waiting for Section 18 application approvals.
Follow Transform's Section 18 application approvals here: http://bit.ly/…
Emily Unglesbee can be reached at Emily.email@example.com
Follow her on Twitter @Emily_Unglesbee
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