Lower Rio Grande Fields Mostly Aphid Free04/06/2016
We are currently scouting 12 commercial sorghum fields throughout all three counties of the Lower Rio Grande Valley.
We have been looking for sugarcane aphids and they have been hard to find. We found a few (<10 sca/leaf) in some Johnson grass in Cameron, Hidalgo and Willacy counties but none so far in the commercial sorghum. I did however come across some volunteer sorghum this week in the Donna area and saw for the first time this growing season high sugarcane aphid numbers ( > 1000 sca/leaf).
However I just want to point out that you all (growers) have really made sure your fields are very clean this year, there has been very little Johnson grass and I only saw two fields with volunteer sorghum. It is important to keep host plants that can cause high sca populations out of your fields which is currently what I have been seeing this year.
So far our neighbors south of us in San Fernando, Reynosa, Rio Bravo and Matamoros Vallermoso are not experiencing any trouble with the sugarcane aphid.
In San Fernando, since they are the furthest south their sorghum is already flowering and they have not had any sugarcane aphid pressure. Hopefully our situation will mimic our neighbors as we get later into the season.
We have a lot of sorghum at V5 stage, seedling sorghum just coming up, and some older sorghum that has just started to get into flag leaf stage. We have picked up on a bit of yellow sugarcane aphids but nothing more than that.
We have received no word yet on the status of sufloxafor (Transform) section 18; but I will keep you informed as soon as I receive word. Another product available and labeled for use in sorghum that shows good control of the sugarcane aphid is flupyradifurone (Sivanto).
Source: Danielle Ortiz, Agfax