The majority of the valley’s cotton has just started squaring pretty good with the exception of some older cotton farther along. In cotton we have been finding thrips, cotton aphids, whiteflies, fleahoppers, spidermites and beneficials. Seeing high numbers of cotton aphids in the mid valley area and down by the river.
If the aphids continue to increase in numbers and we do not receive a hard rain then spray might be warranted especially on the younger 5-7 true leaf cotton. It’s been reported that several cotton fields this week and last week are being sprayed for cotton aphids and thrips. In the seedling cotton still seeing good numbers of thrips in the Mid Valley area where onion fields are present.
Finding very few whiteflies in Weslaco, Mercedes area and south along the river. Reports of red spidermites present in cotton in the Harlingen area. If we continue to have dry weather it will be critical to scout younger cotton for red spider mites to avoid stunted growth from excessive feeding.
In all three counties starting to pick up on fleahoppers but very few at this time. The next four to five weeks will be critical to monitor for fleahoppers as research shows that as many as 85% of total bolls harvested come from squares set during this time period.
Again when scouting for fleahoppers, each time you sample (weekly is good) you will want to check 25 terminals in at least 4 locations of a field starting when the first squares are appearing. If you notice anywhere from 15 to 25 fleahoppers per 100 terminals with squares being lost (rule of thumb: 10% the first week of squaring, 15% the second week of squaring, and 25% the third week of squaring, with treatment rarely needed after first bloom) treatment is justified.
Some of the insecticides used to treat fleahoppers are Assail, Centric, Intruder, Carbine and other insecticides.