consider when climatic conditions favor an This is in no way an exhaustive list epizootic. The timing for epizootics would of sorghum hybrids with resistance to SCA most likely occur in the spring and fall. but those that have been evaluated in Texas A&M AgriLife Research and Extension I have talked exclusively V. trials. Also, it is likely that SCA will occur but there are other fungi that attack lecanii on any of these hybrids but population SCA. Several have been identified from growth will be much lower when compared diseased SCA on sorghum in Mexico. to susceptible hybrids. Unfortunately, there are no entomologists investigating fungal pathogens of SCA in Although SCA resistant hybrids are the U.S. available, it is important that you select products that have the right agronomic mix Predicting SCA outbreaks. to ensure a high probability of achieving Experiences with SCA over the past four production goals. The SCA can easily be seasons suggest SCA outbreaks commonly managed with insecticides when routinely occur during dry conditions and moderate scouted and timely insecticide applications temperatures (mid-70’s to upper 80’s/low are made once the aphid reaches the 90’s). The aphid demonstrates explosive economic threshold. reproduction potential under these cimatic conditions. Spray Tip Summary: SCA populations colonizing the the underside of Evaluation of Hybrid resistance: leaves, often beginning at the base of lower commercial hybrids has been important for leaves. We continue to see good efficacy of identifying/confirming an ever growing list Sivanto and Transform WG, but we wanted of hybrids with resistance/tolerance to SCA. to look at some of the commonly used and A short list of products identified as SCA available spray tips to see if there were from 2016 field trials in north, ‘tolerant’ differences in spray coverage and canopy central, and south Texas can be found in the penetration, as those may be important table below. points of consideration for expected efficacy of an insecticide application. Company Hybrid Maturity Alta AG1203 Medium-late This season, we were able to look at B&H BH 4100 Medium seven spray tips in two trials one in Genetics – Sorghum Rosenberg in boot-stage sorghum on 40” SP 7715 Medium-full Partners Warner W7051 Medium-late DKS48-07 DeKalb Medium REV9782 Terral Medium-full
consider when climatic conditions favor an epizootic. The timing for epizootics would most likely occur in the spring and fall. I have talked exclusively V. lecanii but there are other fungi that attack SCA. Several have been identified from diseased SCA on sorghum in Mexico. Unfortunately, there are no entomologists investigating fungal pathogens of SCA in the U.S. Predicting SCA outbreaks. Experiences with SCA over the past four seasons suggest SCA outbreaks commonly occur during dry conditions and moderate temperatures (mid-70’s to upper 80’s/low 90’s). The aphid demonstrates explosive reproduction potential under these cimatic conditions. Company Hybrid Maturity Alta AG1203 Medium-late B&H Genetics BH 4100 Medium Sorghum Partners SP 7715 Medium-full Warner W7051 Medium-late DKS48-07 DeKalb Medium REV9782 Terral Medium-full Hybrid resistance: Evaluation of commercial hybrids has been important for identifying/confirming an ever growing list of hybrids with resistance/tolerance to SCA. A short list of products identified as SCA ‘tolerant’ from 2016 field trials in north, central, and south Texas can be found in the table below. This is in no way an exhaustive list of sorghum hybrids with resistance to SCA but those that have been evaluated in Texas A&M AgriLife Research and Extension trials. Also, it is likely that SCA will occur on any of these hybrids but population growth will be much lower when compared to susceptible hybrids. Although SCA resistant hybrids are available, it is important that you select products that have the right agronomic mix to ensure a high probability of achieving production goals. The SCA can easily be managed with insecticides when routinely scouted and timely insecticide applications are made once the aphid reaches the economic threshold. Spray Tip Summary: SCA populations colonizing the the underside of leaves, often beginning at the base of lower leaves. We continue to see good efficacy of Sivanto and Transform WG, but we wanted to look at some of the commonly used and available spray tips to see if there were differences in spray coverage and canopy penetration, as those may be important points of consideration for expected efficacy of an insecticide application. This season, we were able to look at seven spray tips in two trials – one in Rosenberg in boot-stage sorghum on 40”
SCA%202016%20Summary%20Rolling%20with%20Bowling%20Newsletter%20Edition%207%20(1).docx