Wednesday, August 18, 2021

West Texas Agricultural Chemicals Institute Annual Meeting

West Texas Agricultural Chemicals Institute's 2021 meeting is scheduled for September 14th at the FiberMax Center for Discovery in Lubbock (1121 Canyon Lake Drive).

Link to online registration: https://wtaci.eventsmart.com/

Onsite registration begins at 7:30 am on 14th September.


Thursday, July 22, 2021

Sugarcane aphid is here, fall armyworm higher than normal, spider mites on the doorstep

It has been a fairly quiet summer so far in corn and sorghum, but that seems to be changing now. Independent crop consultants reported finding sugarcane aphid colonies in sorghum in southern Hale County earlier in the week, and we had no trouble finding them at the Halfway Experiment Station today. I also found them at the Lubbock Research and Extension Center on the first sorghum leaf I looked at. These were small colonies of 100 or so immature aphids surrounding one adult. At Lubbock we are just now starting to get small amounts of honeydew accumulation. It is time to start scouting your sorghum. 

We had a really big fall armyworm flight five weeks ago as I reported on June 16. The next generation is more numerous than average as well according to the pheromone trap data from Lubbock this week.

Of course we need to scout sorghum for headworms and non-Bt corn setting ears, but this big flight might also be a problem for hay production, and in fact I got a call from a Lubbock County producer yesterday. This is the first such Lubbock County call I have had in several years. The southern and central parts of Texas got slammed by FAW this year, but such high numbers are not as common here. In response to the slamming downstate, my colleagues produced a quick guide to fall armyworm control in pastures

The wet, cool and humid conditions have been good for corn and sorghum and bad for spider mites. However, as the temperatures rise and humidity drops now, spider mite populations are beginning to recover. These populations increase rapidly as corn enters tasseling, and all corn fields should be scouted. 

Things are happening fast in all of our crops. If you want the latest news then consider signing up for our weekly Southern High Plains Pest Management Audio Updates. Area IPM Agents record and distribute this 7-8 minute news report on Wednesday afternoon after they have been scouting, and you will have a text link to the audio file within 30 minutes of finishing the recording. You can sign up here. We don't track you, won't try to sell you an extended warranty on your vehicle, and you can opt out at any time just by sending a text with the with the word "STOP". Relevant news with no commitments. 

Wednesday, July 14, 2021

About those seed treatments .... A really good and balanced article

We live in a time of fake news; coverage designed to mislead and advocate one viewpoint. No, I don't need any scientific citations to back this claim up; we all know it is true. I'm writing tonight to bring a very balanced and well-referenced article to your attention, one that deals with the benefits and downsides of the seed treatments put on our corn, cotton, soybean and other seed. 

Beginning around 15 years ago, seed treatments became commonplace on corn seed, and it is now virtually impossible for High Plains growers to buy any seed without these treatments. Research has shown that the treatments often provide little if any benefit, but sometimes they do, like in our corn that has corn rootworms resistant to Bt toxins. But without the rootworm threat the value of seed treatments is far more questionable. On the other hand, cotton often benefits because of the near-constant thrips pressure early in the year, and the fact that aldicarb is not routinely used at planting anymore. Today we buy a whole package in a bag; crop genetics, Bts, insecticides, fungicides, and more. It is no longer a simple choice, and in most cases there is no longer a choice to buy one component without all of the others. 

In what I consider to be a rare moment of good journalism these days, a writer at Progressive Farmer DTN has written a thoroughly documented article on the issues around seed treatments. She provides web links to many reputable sources that either support seed treatments or argue against them. Spend some time and read it; you will both agree and disagree, but remember that long ago that is what good journalism used to be like: https://www.dtnpf.com/agriculture/web/ag/crops/article/2021/07/13/seed-treatment-overload-unintended. I have suggested to TAMU that this article become required reading for Integrated Pest Management on campus; farming is a complicated business and we have choices, some of which serve us well, and some of which do not, and the difference may depend on whether one is looking at the short term or long term. It is complicated. I am grateful that a real journalist did the hard work to examine all sides of an issue, provide evidence each way, and let the reader decide. 

Tuesday, July 13, 2021

Cotton fleahoppers in South Plains cotton

There have been several reports of treatable levels of cotton fleahoppers in cotton. Herbicide applications and destruction of weed hosts is likely behind increased fleahopper activity in cotton at some locations. Cotton fleahoppers can cause substantial square loss if present in sufficient numbers especially during the first three weeks of squaring. They are much smaller in size than the lygus bug and are pale green in color. Both adults and immatures feed on small squares, causing them to shed. When scouting it is important to visually examine the terminal of plants which is where fleahoppers normally concentrate, watch any adults taking flight and monitor square retention. Include both adults and immatures in the count. The economic threshold for South Plains cotton is 25-30 fleahoppers per 100 terminals. Cotton fleahopper is relatively easy to control with insecticides. Insecticides that are commonly used include Carbine, Centric, imidacloprid, Intruder Max, acephate, and dicrotophos.

Scouting video: https://www.youtube.com/watch?v=epVctkRkTHs&ab_channel=TexasA%26MAgriLifeExtensionEntomology

Cotton fleahopper immature (pic: Xandra Morris)

Cotton fleahopper adult (pic: Salvador Vitanza)

Wednesday, June 16, 2021

Fall Armyworm Flight 7.7 Times Average

Corn and sorghum withstood our severe weather quite well this spring, and most fields got a good start. The first cloud is now on the horizon because fall armyworm pheromone trap captures are unusually high; 7.7x the 10 year average. The graphic below shows this year's captures and the 10-year average for my traps at the Lubbock Research and Extension Center. 

Whorl stage sorghum and corn take take a lot of leaf damage, perhaps 30% tissue loss before yields are affected. (This number is shaky and has little research behind it.) These big flights in late spring were uncommon prior to about four years ago, and I do not know why they are now becoming less rare. 

The next question would be how our high numbers now will affect numbers in the next generation. The graphic below shows the seasonal captures in 2019, the last year we had a really high spring flight. 

The first peak in 2019 was about two weeks earlier than it is this year, and it resulted in heavy flights four and a half to six weeks later as the progeny of these early moths completed development and became adults. 

It does not always happen that a big late July flight follows a big early June flight, as illustrated by the 2018 trap data below. 

The bottom line is that our susceptible crops should be scouted very soon for larvae from this generation, and increased scouting five to six weeks down the road would be a good idea. Insect development is based on temperature to a large extent, so we need to watch for another large flight to begin in late July. The timing will likely elevate our headworms in sorghum. Unlike corn earworm that prefers to lay eggs in sinking corn, fall armyworm will lay eggs long past the brown silk stage, and the resulting larvae can still do a lot of damage to corn ears even in the dent stage and later. 

In recent years my traps have been the northern limit of where we monitor fall armyworm. However, IPM Agents John Thobe (Parmer, Bailey and Castro counties) and Dagan Teague (Crosby and Floyd counties) set up traps last week. These will give us a look at how far north fall armyworm might be a problem. 

You can sign up for our weekly IPM Audio Update for the Southern High Plains, a short 7-8 minute summary that we record and deliver on Wednesday afternoon. It covers everything we are finding in the field, and once you sign up you will get a short text message with a link to the audio file online. The signup is here

Tuesday, February 2, 2021

Persistent, Friendly Nematodes Control Corn Rootworm in Texas and New Mexico: February 18th Presentation

Texas A&M Extension Entomology has been conducting a joint research project with Dr. Elson Shields from Cornell University for the last four years. We have shown that persistent, insect-killing nematodes (that are harmless to plants) have the ability to lower corn root damage whether the crop is Bt or non-Bt. And these nematodes persist for many years and just keep killing, even across crop rotations. 

Our research at Dalhart was featured in a DTN/Progressive Farmer article last year under the title "Invasion of the Rootworm Snatchers", and it will give you an idea of what these nematodes do to corn rootworm larvae. More recent work near Roswell, New Mexico, has demonstrated that center pivot irrigation is an excellent way to apply the nematodes. 

Dr. Shields and Drs. Jourdan Bell and Pat Porter are hosting a Zoom meeting on February 18th from 9:30 - 10:30 am. Dr. Shields will explain how these nematodes work (and why they are different from commercial nematodes that do not persist in the soil). He will also present research data from our trials near Dalhart and Roswell. This is new and powerful technology, so we have left plenty of time to answer any questions. 


As an added bonus, New Mexico State University has demonstrated that these nematodes persist in alfalfa stands and are a likely candidate to provide durable control of whitefringed beetles that can devastate a stand of alfalfa. Research in New York has shown that one application of these nematodes provides at least 15 years (and counting) of control of a cousin of our whitefringed beetles.  

Wednesday, September 30, 2020

Phaseout of Most Bt Corn Hybrids Proposed

 My recent post discussed the proposal by EPA to drastically change the resistance management regulations around Bt corn and cotton. You can submit a comment here before November 9th. The proposal is hard to find on the EPA website, so I have reposted it here.  Part of the plan is to phase out all single toxin Bt corn hybrids within three years, and all pyramid (multi-toxin) hybrids that do not contain Vip3a within five years. 

Assuming we don't get any wonderful new technology in the next few years, this would leave southern corn growers with two choices; grow a pyramid hybrid that had Vip3a, or grow non-Bt corn. (It would also leave cotton growers with just the 3rd generation varieties containing Vip.) There are some implications for resistance management of corn earworm/cotton bollworm that are being discussed should this come to pass, like having all Bt corn and Bt cotton in the south expressing Vip, while at the same time the older toxins are failing and less able to provide any protection against resistance developing to Vip in the pyramid with older toxins. Essentially, Vip would become a single toxin because the pyramid could not protect it. The same EPA proposal is attempting to fast-track the removal of old single toxin corn hybrids because they pose a very clear danger for resistance evolution. I explained why this is so back in 2018.

Another outcome would be that corn growers would have a drastically shortened list of hybrids from which to choose. The EPA proposal simply listed the hybrids to be removed by their registration numbers, which is regulatory-speak and rather foreign to most of us. However, yesterday, Emily Unglesbee at DTN/Progressive Farmer posted an article that put common names on these corn and cotton hybrids. The title of the article is Bt on the Chopping Block, and I encourage you to read it. 

Chris DiFonzo at Michigan State University is lead author of our "Handy Bt Trait Table For US Corn Production", and she has created a new table that shows what will be left for caterpillar control after the proposed phaseout. Here is a pictorial representation of the bottom line.

The 8 survivors. 

The 34 types of Bt corn currently sold.

The Handy Bt Trait Table will give you a high resolution view of hybrids currently sold.