—by the KSRE Field Crop Extension Entomology Team
This week, Kansas received a section 18 approval for the use of Transform (sulfoxaflor) against sugarcane aphid for 2016, which will give sorghum growers two effective materials to manage aphid infestations. Note, there are differences in price between these two products, which should be factored into any treatment decisions, especially when multiple applications may be necessary.
Recent reports have sorghum receiving insecticide treatments for relatively light populations of sugarcane in south Texas, but the aphid is beginning to slowly move north, so the potential exists for much earlier infestation of Kansas sorghum this year. There are also confirmed reports that the aphid overwintered on Johnsongrass rhizomes just north of Lubbock, TX. This is about about 80 miles further north than in 2015. Reports from Texas indicate some of the cultivars rated as resistant seem to be holding up well, probably with the assistance of good natural enemy populations.
The Sorghum Checkoff has a list of ‘tolerant’ (= resistant) hybrids, but it does not indicate any regional adaptations for the hybrids. We have not yet ranked Kansas-adapted hybrids for resistance to sugarcane aphid, but efforts are underway to evaluate hybrids this summer. We strongly recommend that growers and extension agents contact their local entomology specialists for advice, as management recommendations will vary regionally.
Scout early, scout often, and know before you spray!