The forecast, unfortunately, would suggest we are in store for another hot and dry week. That persistent weather pattern makes the challenging aspect of weed control more difficult which leads to questions. One common one is how long a residual herbicide will persist on the soil surface before a rain activates it? Another common question during long stress periods is the poor weed control from a POST application due to resistance or dry weather. Continue reading
I’ve received several phone calls about spider mites increasing in cotton around West Tennessee. Spider mites favor hot, dry weather and will often become an issue after plant bug applications are initiated. UT recommends treatment when 30-50% of plants are showing signs of injury and spider mites are still present. This may be too aggressive under low stress conditions, but most of the crop is currently under substantial heat and drought stress. Treatment options are fairly limited and most are mite specific. Abamectin based products are typically the first option because they are economical and effective. There are a couple different formulations of abamectin that are different lb/ai per gallon products. Below is a rate conversion of 0.15 lb ai/gallon formulations (Willowood Abamectin 0.15 EC, etc) to 0.7 lb ai/gallon formulations (Agri-mek SC 0.7, Willowood 0.7 SC, etc).
5.0 fl oz/a = 1.0 fl oz/a
7.0 fl oz/a = 1.5 fl oz/a
8.0 fl oz/a =1.75 fl oz/a
10.0 fl oz/a = 2.0 fl oz/a
Abamectin rates below 7.0 fl oz/a or 1.5 fl oz/a should be avoided due to potential resistance issues and the increased likely hood of retreatment.
Other mite products such as etoxazole (Zeal, Stifle) are mite growth regulators that work very well but are more expensive and somewhat slower than traditional miticides. Fenpyroximate (Portal) is a contact miticide that has a shorter residual than abamectin or etoxazole but works very well. Bifenthrin alone is not an adequate miticide and should be avoided.
Products used for controlling plant bugs, bollworms and stink bugs (OPs, pyrethroids) exacerbate mite populations and their use, especially during hot dry conditions, should be delayed until after bloom if possible. Mite populations can rebound quickly after miticide applications so diligent scouting is critical to slowing the spread of mites across a field.
More times than not, when a cotton planter left a TN field in 2022, a thunderstorm bringing ~2″ of rain and cool weather would arrive 3 days later. I’ve walked more replants this year than ever before and unfortunately the old saying ‘if you are on the fence, keep it’ rarely applied; in many fields, we weren’t anywhere near the metaphorical fence. Still, Tennessee’s ragged cotton crop has generally turned the corner and mid and late June have been cotton weather; our earliest cotton reached early bloom well prior-to the 4th. In this blog, I cover a few things to keep in mind as we begin to apply PGRs to more acres and look to push a few slower farms into ‘taking off’.
Even with some rain in the forecast, the dry to drought conditions in Tennessee have reduced disease development and hence reduced the potential to break even on a fungicide in corn.
The MidSouth Cotton Specialists’ Working Group (MSCSWG) has compiled the 2022 Cotton Variety Guide for Plant Growth Regulation. This information was constructed based on the MSCSWG’s experience with each of the varieties, company ratings, and discussions with other agronomists. To access a pdf of the document, click the above image.
In season plant tissue testing helps producers monitor plant nutrition and can be useful in diagnosing nutrient deficiency. Detecting deficiencies early can allow the corrective or preventive action that will minimize yield effects from deficiency during the growing season. Nutrient concentrations vary greatly with plant growth stages and the part of the plant that is sampled so specific sampling guidelines and interpretation have been instituted to prevent false diagnosis. Continue reading
What are some options to control volunteer XtendFlex soybeans in XtendFlex cotton fields? This issue is something that we need to do research on as there is no data. As such in answering the question one has to rely exclusively on experience. Unfortunately, all the experience that I and my Midsouth colleagues have does not hint at a real good option to remove these volunteers. Continue reading
Some of the earlier planted cotton fields will soon be entering the true “laying it by” application timing. Given that some are clearly not successful spraying Palmer amaranth, goosegrass or junglerice with glyphosate + dicamba (Picture 1 and 2), going back to an “old school” layby is a good plan. Continue reading