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Tuesday, March 31, 2020

Online Cotton Conference April 8th.

 Taken from AgriLife Today:

The Texas A&M AgriLife Extension Service will be holding an online early season cotton conference on April 8 from 8:30 a.m. to noon on the web conferencing platform Zoom. The cost is $10.
Producers may click on this link to register, and payment may be made online via credit card. Once registration and payment are complete, participants will get a Zoom link to the online meeting. Participants who would prefer to pay by check can send it to Mitchell County Producers Board, 440 E. 2nd St., Colorado City, TX, 79512.

There will be three Texas Department of Agriculture continuing education units available — one general, one integrated pest management and one for drift minimization.

“This event will provide our producers with some excellent, timely information on issues and decisions that are important to them right now,” said Danny Nusser, AgriLife Extension regional program leader, Amarillo.

The topics and expert speakers are:
— Overview of Cotton Weed Management in 2020 – Peter Dotray, Ph.D., AgriLife Extension weed specialist, Lubbock.

— Pre-plant Considerations – Murilo Maeda, Ph.D., AgriLife Extension cotton specialist, Lubbock.
— Virus Management (FOV4) and Nematodes – Cecilia Monclova-Santana, Ph.D., AgriLife Extension plant pathologist, Lubbock.

— Integrated Pest Management Panel – Brad Easterling, AgriLife Extension integrated pest management agent, Glasscock County; Kerry Siders, AgriLife Extension integrated pest management agent, Hockley and Cochran counties; Blayne Reed, AgriLife Extension integrated pest management, Hale and Swisher counties; and Suhas Vyavhare, Ph.D., AgriLife Extension entomologist, Lubbock.

“Due to concerns with COVID-19 pandemic and the need for social distancing, AgriLife agents decided to provide educational programming via Zoom online delivery,” Nusser said. “We encourage cotton producers everywhere to participate in this unique and important online conference.”

Susan Himes
Thanks Susan!
Hope to "see" you all there!  Should be good stuff.
Blayne Reed

Monday, March 30, 2020

Army Cutworms in West Texas Wheat – Final results from our efficacy trial

Army Cutworms in West Texas Wheat – Final results from our efficacy trial

              With the outbreak of army cutworms in many of our local wheat fields for grain, we, the IPM Team on the High Plains (Dr. Pat Porter, Dr. Suhas Vyavhare, Blayne Reed, John Thobe, and Dagan Teague), took the opportunity to place an efficacy trial in a particularly heavy infestation in northwestern Swisher County.  We placed this trial in an edge of a failed field where there would be no chance of overspray but the population was more than enough to guarantee a good trial.  The repercussions of this decision would show later.  

In this research trial, we placed three labeled products which are the most likely to offer the best control for the pest.  The treatments consisted of an untreated check (UTC), two rates of Prevathon, Blackhawk, and Baythroid.  On March 12, 2020, we counted our 3 DAT (days after treatment) counts and released those results earlier.  The trial proved difficult to conduct with weather in the form of 3 inches of rain over 5 days, preventing a 7 DAT count until we reached the 10 DAT timeframe.  Then, high winds drove the larva ever deeper into the soil and tried to carry equipment and researchers away.

The nature of the pest proved difficult also.  The army cutworm stays below ground during the day and emerges at night to feed.  Our scouting became better for this sporadic pest with experience making some of our pre-treatment counts inaccurate.  The area of the field where we had placed the trial had shown in our pre-treatment and early scouting to exhibit 5.08 larva per square foot.  We learned that either the larva moved into this area and/or we had missed many of the larva by not ‘digging’ deep enough or thorough enough.  By the 3 DAT and 10 DAT counts the area around the trial and UTC exhibited about 20 army cutworms per square foot, well above the 4 larva per square foot that represents the economic threshold (ET) and more than the 5.08 we counted pre-treatment.  In addition, the larva is mobile.  There was ample evidence that the larva was moving between test plots and from outside the test plot area into our trial.  

This plainly muddied the water of our results.  Yet, we are still receiving phone calls about this pest, either from failed ‘cheap generic’ insecticide treatments and newly found economic populations threatening wheat.  The absolute results of this trial remain eminently important to this date. 
              We tried mathematically cleaning up the data by several methods to make the most sense of it.  We tried Abbott’s formula to normalize unhealthy UTC populations but it is not designed for this situation or unevenly distributed populations, which this trial had.  Then we tried the Schneider-Oreli formula that would adjust mortality of the UTC to zero, no matter how many treated worms had moved into the UTC from the treated plots or untreated worms to the treated plots.  This plainly did not take into account the number of untreated larva that moved into the plots from outside the trial area.  Then we tried the Sun-Shepard formula that normalized the treatments to the percent mortality of treated worms that moved into the UTC.  This also did not take into account the influx of larva into the trial.  

We now feel the best representation of this data is the percent average mortality of each treatment, calculated by the replications.  The reader should understand that a large contingent of untreated larva were moving into the treatments and from the treatments into the UTC, between the treatments, and even out of the trial before dying.  All of that being said, we feel very good about recommending Prevathon or Baythroid for army cutworm in wheat today.

              It is disappointing to see a treatment without what most of us would consider reaching control, or something nearing 100% mortality.  We feel many of the treatments faired far better than this data represents.  Please keep in mind healthy worms were moving into these plots from outside the treated plots and between them.  The heavy rains may have also washed many of the dead worms from plot to plot also.  It was not uncommon to find clusters of 20 or more dead worms in an area on top of the soil, but upon scouting could find just as many below the soil surface, sometimes quite a distance below. Also, these treatments were providing residual control at 10 DAT and following heavy rains and adverse conditions.  Maintaining control here would have been difficult at best and almost impossible to quantify fully with the insect movement issue.  

              The bottom line today is that we feel strongly about recommending either Prevathon or Baythriod for army cutworm control in wheat in West Texas.  At both the3 and 10 DAT counts, while counting blind (not knowing which plot we are in to ensure fairness) we could clearly tell when we were in the UTC, Prevathon, and Baythriod plots.  The number of dead worms versus live would give the plot away every time.  With treatment coverage to control entire fields, Prevathon should offer outstanding control at light rates that still offer the added benefit of saving predators for other pests and possibly other crops later this year.  With the same amount of field coverage, Baythriod, a first line pyrethroid, still offers outstanding control of the army cutworm with a touch more residual in harsh conditions such as heavy rains following treatment.

Blayne Reed

Alfalfa Weevil Alert for Texas High Plains Alfalfa

Alfalfa Weevil Alert for Texas High Plains Alfalfa

              The alfalfa weevil pressure for our Plains Pest Management (PPM) scouting program alfalfa is usually hit or miss.  Some years I see them around economic levels and some years that are just absent.  Even in the seasons I do see them, we don’t always need to treat, and it is usually only for the first cutting.  Many alfalfa fields in the High Plains region are not so lucky with the weevil being an annual and season long issue.  The reasons for this are debatable and hypothetical but I usually attribute it to the few number of fields in my territory that have dwindled with the diminishing water resources.  I suspect that the more serious alfalfa areas in the region have the weevil bad enough in some seasons that we get the overflow., but without serious study, there is no way to make certain the reasons for this usually minor issue.
Alfalfa weevil feeding near growing point, Lubbock.  Photo by Dr. Pat Porter

Light alfalfa weevil damage in Lubbock this week.  Photo by Dr. Pat Porter
              What is certainly known is that the few alfalfa fields in Hale and Swisher counties are very important to the producer investing huge amounts of inputs to raise this alfalfa here and the consuming livestock in the area depending upon the resulting hay.  Without it, feeding costs would skyrocket with high shipping costs.  So, why the alarm today?
Alfalfa weevil larva.  Photo by Dr. Pat Porter

              Last week I made my usual visit to our PPM alfalfa field and found newly hatched young alfalfa weevil larva at a level I had not seen locally before.  This population averaged 12.8 weevils larva per 20 sweeps with the economic threshold (ET) being about 4 per 20 sweeps.  Alongside these weevils were a notable population of aphids.  Plainly these weevils were over ET and needed to be treated.  I recommended prompt chemical treatment with a labeled product that would control the weevils and leave the beneficials to control the aphids.  This week, I returned to our PPM field to find good control, but still more freshly hatched weevil larva, the majority of which were freshly dead or seemed sick with residual control still having good impact.  With this very high level of infestation, I opted to spot check a few other fields in the area I am aware of.  These fields today exhibited 20.25 and 16.5 weevils per 20 sweeps in spot checks.  This season’s alfalfa weevil issue seems much larger compared to a ‘normal’ year’s pressure.  So much so, I can imagine more traditional alfalfa growing areas could also be seeing higher than usual pressure and a regional-wide alert should go out, alongside a few tips on how to scout for this key alfalfa pest.  Aid to point, Dr. Pat Porter found ample weevils at the Lubbock Research Farm on a sample alfalfa plot this weekend.

Photo from PPM alfalfa field this week near Tulia.  Note old feeding damage with new growth showing little to no new feeding damage following treatment.  Photo by Blayne Reed.

              Visual scouting with kneeling and inspecting sprigs and growing stems for damage can find some of the pest, but to truly find the level your field is at, you need a bit more knowledge, and possibly some simple tools.

Alfalfa Scouting
              There is one main tool you almost must have for scouting alfalfa correctly and accurately.  That is a sweep net.  No, entomologists do not use them to chase butterflies across pastures or parks as cartoon caricatures show.  At least not often.  They are much more useful to gleam insects from vegetation.  If done correctly, the operator will find insects in higher numbers than any visual inspection would ever find.

Common sweep net used in checking near Tulia this week.  Note strong wire frame, durable net, and long handle.  Photo by Blayne Reed

              The idea is to vigorously ‘sweep’ the net through the upper 1-3 inches of vegetation reversing rapidly as stepping forward for a backhanded reverse sweep to gleam the adjacent vegetation.  This ‘backhanded’ sweep should be made after twisting the net over so that the open net is ready to receive the next sweep.  Ideally, this process should be repeated, sweep, twist, step, sweep, until you have completed 20 sweeps.  For most other crop pest scouting where sweep nets are essential, this 20 sweep per data set is the standard. 

              On the last ‘sweep,’ pop the captured insects in the bottom of the net and harvested vegetation over with the last twisting momentum to prevent escapes.  This process sweeping and capturing motion must be maintained vigorously without pause making use of inertia and other forces so that ‘swept’ insects have not chance of escape.  Once completed, place the net handle between the knees so both hands are free to carefully draw up the bottom of the net little by little.  Along the way, slowly identify all insects caught.  Remember, not all insects caught are pests.  Many are inconsequential and better yet are beneficial.  It should be good to know exactly how many good insects you have in the field to combat the pests.  Count all pests and beneficias alike.  Once the net is clear, I like to kneel and visually inspect two alfalfa plants.  Record all relative insects, plant damage, and make note of any weed populations in the area.  This completes one data set.  There should be 4-8 data sets taken per field, size depending, to form a proper representation of the insect population present.  These data sets should be made evenly across the field and results averaged for each species. 

Once the data set is complete, pop the contents over to trap insects in the bottom of the net.  Photo by Blayne Reed.

Alfalfa weevils near Tulia this week.  Note both dead, sick, and live larva among sub ET aphids captured by sweep net.  Photo by Blayne Reed
For alfalfa weevil a population of 4-5 per 20 sweeps should be ET, beneficial population depending.  For aphids, there will need to be visual stickiness on about 40% of the plants with more infested before it is economic. 

Photo of the distance traveled across the field near Tulia this week from the pickup to get good data and eliminate any edge or spot effects.  Photo by Blayne Reed.

Good Luck out there folks!

Blayne Reed