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USCP Agronomy Check
BRENT BEAN
LUBBOCK, TEXAS
There was a lot of buzz about sugarcane aphid in 2016, and we learned quite a few lessons that will help us manage for the pest in the future. The United Sorghum Checkoff Program funded more than $300,000 in sugarcane aphid research in sorghum last year, in collaboration with Dow AgroSciences and Bayer Crop Science. The three organizations hosted a day-and-a-half Research Exchange Meeting the first week of January in Dallas with entomologists from across the country, including the Mid-South and Mid-Atlantic, to discuss research findings from these trials. There were approximately 60 participants.
Presentations and discussions focused on answering the following questions:
• Do thresholds differ with susceptible and tolerant hybrids?
• Does the optimum threshold differ with crop growth stages?
• How can we best manage sugarcane aphids at harvest?
• How can we best manage sugarcane aphid in fields where other pests such as midge and headworms are also present?
• What are the minimum rates of Transform and Sivanto Prime that should be used?
• What is the effectiveness and residual activity of seed treatments?
Managing Sugarcane Aphid
Here are some conclusions drawn from the meeting. Sugarcane aphids multiply slower on tolerant hybrids compared to those that are susceptible. Tolerant hybrids may still have to be sprayed, but it will likely take longer for the aphids on these hybrids to reach threshold level.
More research is needed to determine if thresholds can be increased when sugarcane aphids infest sorghum post bloom. However, yield loss is typically less if aphids infest sorghum in the late soft dough or hard dough stages. This at least allows for some flexibility of how soon a field must be sprayed once the threshold is reached. If infestations occur at sorghum bloom or earlier, fields should be sprayed immediately once thresholds are reached to avoid severe yield loss.
All research has shown that in-season control of sugarcane aphids can be achieved with good coverage of the lower rates of Sivanto Prime and Transform. Most researchers suggest 4 oz/A of Sivanto Prime and 1.0 oz/A of Transform. Adding adjuvants to the mix has not been shown to add any control of sugarcane aphids.
The best recommendation if sugarcane aphids are present at harvest is to use no more than the lowest label rate of either Transform or Sivanto Prime insecticides. These can be mixed with glyphosate or sodium chlorate, if desired. Always refer to the product labels for specific recommendations and instructions.
When other pests are present in the field, avoid using those insecticides that are harmful to beneficials, which are important in keeping sugarcane aphids in check.
Seed treatments are effective in giving 30 to 40 days of early season control of sugarcane aphids. Research is on-going on some in-furrow treatments that show promise in extending sugarcane aphid control. ∆
BRENT BEAN: USCP Agronomist
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