This tip was provided by:
Calvin Trostle, Extension Agronomy, Lubbock, 806-746-6101, firstname.lastname@example.org
Ron Schnell, State Cropping Systems Specialist, College Station, (979) 845-2935, email@example.com
Evaluating if Grain Sorghum Hybrids with Seed Company Designation of Tolerance/Resistance to Sugarcane Aphid Are Right for You in 2016
In our last Sorghum Tip we published a list of 19 hybrids that companies have designated as what they believe are there most likely tolerant/resistant hybrids to sugarcane aphid. Since then, as a Texas A&M AgriLife Extension staffer, I recognize that we in AgriLife don’t have enough information (or any in several cases) to publish about these hybrids’ tolerance/resistance and SCA. Thus as a needed Disclaimer on the AgriLife December Sorghum Tip, though AgriLife staff have contributed to information (hybrid trial data, aphid and damage ratings, field observations) to the information Dr. Bean, USCP compiled, we in AgriLife have not verified the company information as well as other sources ourselves, and we have no AgriLife data of any kind on about half of these hybrids.
As an alternative I have written an article with the above title that discusses how you the producer may evaluate whether one of the 19 grain sorghum hybrids noted above is right for you. Read the full edition at http://lubbock.tamu.edu (posted title is “Grain Sorghum Hybrid Selection and Sugarcane Aphid 2016).
As a sampling of the document’s advice, here are five questions you can ask your grain sorghum seed dealer:
1) “What hybrid(s) do you have with a proven SCA resistance gene in its parentage?”
2) “If you do, does that genetic background transfer actual hybrid resistance to SCA in the field?”
3) “What field evidence do you have for this hybrid’s substantial tolerance/resistance? Seedling tests? Field observations? Field insect counts? Yield data?”
4) “Is at least some of your field data from independent or external sources?” (If so, who?)
5) “How does the yield of your current SCA tolerant/resistant hybrid(s) compare to your company’s best grain sorghum hybrids?” (Agronomically, you want to understand the grain yield potential of good grain sorghum hybrids even if susceptible to SCA vs. tolerant/resistant hybrids. If there are significant yield differences be sure to ask/understand if those differences may be due to likely lower-yielding shorter maturity in a hybrid.)
The list of 19 sorghum hybrids noted above that have stronger claims about SCA tolerance/resistance will be maintained by United Sorghum Checkoff Program, http://sorghumcheckoff.com/pest-management/, and it may change with additions and deletions.
Texas A&M AgriLife Grain Sorghum Yield Data & Sugarcane Aphid Tolerance/Resistance
Planting resistant or tolerant hybrids will be vital for long-term management of sugarcane aphid in sorghum. As noted previously, USCP has provided a list of grain sorghum hybrids that are believed to have some level of tolerance to sugarcane aphids. However, identifying well-adapted hybrids with consistent yield performance in your region will remain the most important criteria for hybrid selection. You should not sacrifice significant yield potential to plant resistant or tolerant hybrids. There is no guarantee significant pest pressure will materialize and no guarantee that treatment for sugarcane aphid will be avoided.
The Soil & Crop Sciences Department’s Crop Testing Program collects information on grain sorghum hybrid performance from more than a dozen locations across Texas each year. Results can be found at: http://varietytesting.tamu.edu/grainsorghum/. In addition, hybrids identified as having unspecified levels of tolerance to sugarcane aphids will be summarized along with several susceptible public checks. These results will be available at the website above by the end of the week of January 18th. Again, consistent yield performance will be the most important criteria when selecting hybrids. Hybrids that perform well across multiple locations (regional summaries) and years (2- & 3-year summaries) should be strongly considered. Make sure to select a hybrid that has a maturity rating appropriate for your environment. Several early to medium-early hybrids listed in the USCP report may be appropriate in certain situations (dryland and later plantings in west or south Texas).