Impressions and confussion about the implementation of the new cotton herbicide technologies in West Texas

I asked Nikolas Clarkson, one of our 2017 Plains Pest Management Interns, to cover a hot topic for 2017, The implementation of the new cotton herbicide technologies in West Texas.  Nik and I worked together on this article to keep the facts as facts and share our impressions from what we have seen from the field so far.

            Cotton producers and those that work closely with them are becoming more familiar with the new herbicide technologies and herbicides finally labelled for use this year.  It has not been overnight but we are becoming better aware of how they should best be utilized.  Early in the discussion about these new technologies, there was quite a bit of confusion about these traits and products, what they actually were, and where they could be used.  So, I am going to start off by listing the new cotton herbicide technologies and the herbicides that go with them.

First off, I will discuss Enlist.  This trait is currently only in Phytogen cotton varieties.  The herbicides that can be utilized with these traits are Enlist Duo, Enlist, Roundup (all formulations), Liberty, and all conventionally labeled cotton herbicides.  It is a misnomer that this is 2,4-D cotton.  While the base chemistry is there and the cotton would tolerate the old formulations, they are not labeled and the salt utilized in this formulation is much different which should keep this notorious class of herbicides for moving much, much closer to target and from escaping unintentionally.   

Next, we have Xtend cotton.  For this trait, we can use XtendiMax with Vapor Grip, and XtendiMax from Monsanto and Engenia from BASF, Roundup (all formulations), Liberty, and all conventionally labeled cotton herbicides.  This trait has also been miss-named by layman as Dicamba cotton.  Much like Enlist cotton, the Xtend cotton can tolerate the older formulations of this class of chemistry but these herbicides should be improved on multiple values.

With the improvement factor of all of these newer herbicides coinciding with the release of these cotton traits and a conscious fair price setting near the cost of the old herbicides, I cannot see any reason to use the older herbicide chemistries with these new traits.  Hopefully, no one is as the labels of these new herbicides really need to be adhered to if we are to keep the traits registration.  It seems the application of these technologies in cotton is under the EPA’s microscope.

            All of that does seem quite the mouthful.  It has taken almost all summer for me to wrap my head around these technologies, herbicides, and implications as we scout fields in front of and behind weed control applications. 

            In following these labels, we have had some hard-earned lessons, and some successes.  Drift has been a paramount concern for everyone in the area this year.  Built into the labels of these new herbicides are some serious restrictions about nozzle size and pressure to ensure that drift is minimized and won’t make a significant impact on any neighboring fields.  While there notable are drift incidents around the area, Blayne seems to feel it may actually be less this year compared to most growing seasons.  This is likely due to the fact everyone is paying closer attention and correcting any mistakes much quicker.  What we have noted more of are, as Blayne calls them, ‘self-inflicted wounds,’ or damage to cotton from contaminated sprayers, sometimes from custom applications and sometimes from the producers own sprayer.  This seems to be another way that an all Roundup system in the region has ‘spoiled us’ and that is in tank cleanout.        

Producers need to know how to properly clean out their spray tank of Enlist Duo, XtendiMax, Engenia, or any other new herbicides once they are finished using it to prevent from becoming an issue for the next treated field.  It is not as easy as we have been doing recently.  Each herbicide has some minor but specific and labeled differences in how tank should be cleaned out.  For the sake of time I am about to going to go with the recommended way on the Enlist Duo product label.  The time to clean out the tank is right after you are finished using it. Do not wait until the next day.  Triple rinse is a minimum, not a suggestion with these herbicides.

For the first rinse, completely drain the system and leave for about 5 minutes and then fill the tank with water to about 10% of the total tank volume and circulate it throughout the entire system for 15 minutes and then spray it out the boom.  Drain out the system again for 5 minutes and remove and clean the filters.  For the second rinse fill the tank with water and add the recommended rates of cleaning agents.  Circulate the solution for 20 minutes and then let it stand for a few hours.  For the next rinse, drain the whole spray system again, fill the tank with clean water to 10% of the tank volume and circulate so that all surfaces are contacted for 15 minutes. Drain the entire system again and remove nozzle tips and clean them separately.  

This is not any ‘fun.’  Blayne makes sure we follow these rough guidelines for our backpack sprayer and bottles we use for the Plains Pest Management research plots, so I feel the pain of this extra work.  In a zero-tolerance situation, such as a small plot research trial or an Enlist field about to be sprayed with a sprayer that has just sprayed Enginia or XtendiMax (or vice-versa), the results are terrible and impact unpredictable.  In these cases, either a ruined trial or a severely damaged field, which I have seen a fair amount of this season.

Resources:

Keeling, J.W. Keeling, E.M. Koonce, A.T. 2015. Weed Management with Engenia In Bollguard II XtendFlex Cotton. Minneapolis, MN. Entomological Society of America.

Reed, B., 2017.  Herbicide Discussions and Intern Trainings.  Plains Pest Management.

Thanks Nik,

Blayne Reed

Plains Pest Management News - August 4, 2017

Good Afternoon!

Below you will find a link to the latest issue of the Plains Pest Management Newsletter.

Plains Pest Management News - August 4, 2017

Thank you,

Blayne Reed

Plains Pest Management News - July 28, 2017

Good Afternoon!

Below you will find a link to the latest issue of the Plains Pest Management Newsletter.

Plains Pest Management News - July 28, 2017

Thank you,

Blayne Reed

Sugarcane Aphid Confirmed in Hale County

The following was written by Dr. Pat Porter, District 2 Entomologist:

Greg Cronholm, Independent Crop Consultant and retired Extension IPM Agent, just called (7-24-17) to report finding sugarcane aphid in Hale County about 3 miles from Plainview. Most were small colonies but some were a bit bigger. Similar to what we saw with the early infestations  in Crosby County last week, he said his colonies were in the upper ½ of the plant.

For the southern High Plains we now have sugarcane aphid confirmed in Crosby, Lubbock, Hale and Floyd counties. 

Thanks Pat,

Blayne

LEPA, a brief background and best management practices.

Folks, I have asked one of our 2017 summer interns, Trey Buxton, to address a topic with a few practical answers about LEPA irrigations.

LEPA, a brief background and best management practices.

It was the late 1970’s is when the idea behind LEPA irrigation systems for pivots first entered practical research trials for its potential to maximize irrigation inputs by saving energy, increasing irrigation efficiency from pump to root zone, and water use efficiency by the crop.  It was developed for areas like here in West Texas that had center pivot irrigation that had limited access to water and high and increasing energy costs. Dr. Bill Lyle and James Bordovsky should receive the most credit for the developing LEPA at the Lubbock-Halfway Texas Agricultural Experiment Station. 

Some people might wonder why a producer would want to water their crop on LEPA stage or even what the difference is. “LEPA” stands for Low Efficient Pressure Application.  LEPA has been tested and proven that 95% to 98% of the irrigation water pumped (at ever increasing costs) gets to the crop’s root zone.  Granted, that is under ideal situations with all equipment working at peak efficiency but even with some give on those numbers it is so much better than the 35% efficiency with gated pipe and the 45% to 60% expected for the higher pressure pivots of the day that sprayed water through the air and across the soil surface.  In its earliest design, LEPA applied water by hoses that drag along the ground and release water without waist through air exposure and evaporation while making use of a much lower operating pressure.  The hose concept has been revisited and improved upon with various designs over the years with some impressive savings, but when most of us consider a LEPA outfitted pivot we envision the nozzles with changeable settings, with the bubble mode set, resting at the end of a long hose dangling from the pivot about 4 to 18 inches above the surface. The hoses are usually separated about every 60 to 80 inches depending on row spacing so that rows are skip row irrigated.  So, with LEPA type pivot irrigations plants do not get water applied to the plant and soil from above under high pressure with plenty of evaporation opportunities, the water is applied as close to the soil surface as possible, preferably into the bottom of a furrow, which then soaks into the soil and directly to the roots with minimal waste.  It is said that LEPA works best on farms that have sandy or loamy soil because the chances of runoff is not as likely to happen like it would if you had soil that is heavier or tighter.  The chances of runoff also increase in no-till systems and on steep slopes.  From this original LEPA idea, several pivot and nozzle / hose types have been developed along the same principle.  Most of these more efficient pivots have adjustable nozzles with at least a spray mode and a bubble mode.

With these types of water savings, it can be difficult to understand why we would ever even use a spray mode and go somewhat back to a less efficient method of irrigation.  The truth is, LEPA is great for in-season irrigation efficiency, but terrible for wetting the seed zone and establishing a fledgling crop.  Those young plant roots cannot find the moisture from LEPA irrigations and the seeds certainly cannot.  So, a very common question from producers is, “When should I change from spray to bubble mode to best maximize my irrigation efficiency without hurting my young plants and stand establishment?”

There really isn’t a set stage for when you should switch over to LEPA. The proper time to switch over to LEPA is the when the plants are grown enough to find the deeper held and better applied water.  Some people will make the mistake of switching to LEPA before the crop is mature enough and the young plants will drought stress and perhaps even die before ever finding that deep moisture so far away from the seed zone.  You have to let the plants grow and develop strong roots in the ground so when you switch over to LEPA the roots will be able to reach the water.  Sometimes we need to help them get to the point that they can find that water on their own with spray irrigations and we are very likely to need even irrigations to germinate our often dry planted seeds.  More producers likely make the mistake of staying in spray mode too long and waist some of their precious water by not being as efficient as they could be.  Although that is the safer play and there isn’t exactly a set stage for when you should change over to LEPA, if you had to choose a stage to switch over it’d somewhere between match head square and ¼ grown square stage.  This is about the stage that cotton plants start seriously building lots of fruit sites and vegetative structure.  With a similar process going on below ground with the root system, this is generally the first time cotton plants can ‘look’ for soil moisture themselves. 

References

Leon New and Guy Fipps, Center Pivot Irrigation, Texas Agricultural Extension Service

Porter, D., Irrigation For Small Farms

Amosson, S. , Lal Almas, L., Girase, J.,  Kenny, N., Guerrero, B.,  Vimlesh,K.,  Thomas Marek, T.,  B-6113, Texas A&M AgriLife Extension Publication, Economics of Irrigation SystemsLyle, William M., 1982, Water Saving Techniques, Journal of Agronomic Science (pp 72-82).

Reed, B. Conversation about LEPA systems, 2017, Internship with Plains Pest Management Association

Thanks Trey!

Blayne

Plains Pest Management News - July 21, 2017

Good Afternoon!

Below you will find a link to the latest issue of the Plains Pest Management Newsletter.

Plains Pest Management News - July 21, 2017

Thank you,

Blayne Reed