The majority of grain sorghum in the Valley is either at boot stage or has already headed out and is now flowering. Many fields have either been irrigated in the last week or will be irrigated this week.
Make sure before you go ahead and water your fields to check for sugarcane aphid and see if it is practical to spray. From last week into this week we have been seeing small sugarcane aphid colonies on sorghum leaves (5-15sca/leaf) in the commercial sorghum fields that we monitor but nothing that warrants spray treatment yet.
Many adult winged aphids (alates) have been taking flight into the fields and started to reproduce. However along the river and near the coastal regions we are starting to see some honey dew secretions on some leaves already and slightly higher colonies of 50-150 sca/leaf on scattered plant here and there.
It is critical during the next 3 weeks to monitor your sorghum closely. Monitor sorghum fields every 3-4 days. I have received reports of some producers spraying for sugarcane aphids in their sorghum.
Products available for use in sorghum to treat the sugarcane aphid are Sivanto and Transform. Both products offer good control of the sugarcane aphid. Transform received a Section 18 for use on sorghum that became effective on April 8 2016 and expires on April 8 2017. Note that when making a Transform application you have to have a copy of the label in hand. Also note that the Section 18 label for Transform this year stipulates that the product Transform cannot be applied < 3 days pre-bloom until after seed set.
Sivanto also received a 24c label reducing its PHI from 21 days to 14 days (same as Transform).
For those who were not able to attend the SCA meeting last week or for those who want to take a second look at the presentations you can find them available at my webpage as well as the product labels for Sivanto and Transform plus the current Pest Casts for the 2016 year.