Corn and sorghum harvest is well underway. Soybeans and cotton fields are maturing rapidly. The weather forecast predicts hot, dry conditions for the foreseeable future, with some rain chances toward the end of next week.
I have seen some stink bugs in cotton and soybean fields but the decision to treat depends on the maturity of the crop.
Soybean fields are not safe from stink bugs until R7 (beginning maturity) and I may want to control red banded stink bugs for another week after that depending on the maturity of the less mature parts of a field.
Cotton fields are considered safe from stink bug feeding once the field has 450 heat units (HU) after cutout, or 5 Nodes Above White Flower (NAWF).
A Heat Unit can be calculated by subtracting 60 from the average of the high and low temperature of the day. On days with a high of 95 and a low of 75, the daily HU accumulation is 25 Heat Units. At this rate, it takes 18 days to accumulate 450 HU.
The decision to cease protecting from stink bugs is complicated by the fruit loss we have had on the upper parts of plants. In some fields there are 3-5 empty branches between the white flower and the highest harvestable boll. This means the highest boll may be 9-15 days older than the first position white flower and you may want to consider this in your decision making.
Many fields have open cotton bolls and it is hard for me to agree to treat stink bugs in cotton fields with open bolls.
I expect we could be defoliating cotton in a few weeks and may see pickers running before the end of July.
I am looking for cotton fields to spray Harvest aid trials in Calhoun, Refugio, and Victoria Counties. The trials will have around 14 treatments and will require 84 rows, 100 feet into the field and will not have untreated cotton.
Give me a call if you have a field I can use 361-920-1138