Biopesticides for the Control of Whiteflies

by Holly Davis, Ph.D. – Certis Biologicals Field Development Manager, Southwestern U.S.

Whiteflies have been a persistent problem this year for Texas growers.  These insects can be especially difficult to control in organic production. There are numerous OMRI certified biologicals, or biopesticides, available to growers but, to get the best efficacy, it is important to understand a few things about them. 

First, biopesticides need to be applied at the first sign of whitefly activity.  Trying to clean up a situation where plants are heavily infested with all life-stages of whiteflies (or any insect or disease) is extremely difficult and there may be no escaping loss of quality and/or yield.  The use of yellow sticky cards in greenhouses or around field margins can help detect whitefly activity early so that applications can begin in a timely manner.

Most biopesticides labelled for whitefly control are contact pesticides, meaning they must either be sprayed directly on the pest, or the pest must move across a treated surface while the biopesticide is still active. This can be tricky for insects like whiteflies which spend the majority of their time on the underside of leaves, sometimes deep within plant canopies.  For that reason, it is important to use the correct amount of carrier, the right spray equipment, and nozzles, and to include a spreader sticker when appropriate to ensure product is distributed as evenly as possible and adheres to plant tissue.  

Once applied, biopesticides may not persist in the environment for a long period of time.  Many are degraded by sunlight and/or other environmental factors.  Remember, most do not move through the plant (are not systemic) so any new plant growth after application will not be protected.  For this reason, biopesticides need to be applied on a regular interval, often every 7-14 days, to ensure that whitefly populations do not build up between applications.

Finally, it is important to understand what to expect from different types of biopesticides.  For example, while some products like Des-X®, an insecticidal soap concentrate, have the advantage of providing a quick knock-down of whitefly populations by breaking down the insect cuticle, there is no residual efficacy.  Any insect that lands on a leaf after the treatment has dried will not be impacted.  Other products such as the entomopathogenic fungi, Beauveria bassiana, found in BoteGHA®/BotaniGard®, may take several days to kill whiteflies by overwhelming them with fungal spores, but can persist in the environment and continue to infect immigrating or emerging insects.  This typically happens when there is high relative humidity and/or a dense plant canopy. 

This persistence can be recognized by mycosis, or the presence of emerging spores from a fungus-killed insect. However, lack of visible mycosis does not mean an entomopathogenic fungi is not working. In many cases, whiteflies may simply darken and desiccate.

No matter what biopesticide you chose, it is incredibly important to read the label and understand the product to get the best efficacy possible!

A big thanks to Dr. Davis for supplying such helpful information. For more information on Certis Biologicals, please visit https://www.certisbio.com/

Peanut Seedling Disease Trial

This peanut seedling disease trial was established to simply evaluate organic seed/soil treatments at plant for any sign that they might prevent a complex of seedling diseases that affect peanut seed germination.  Typically, a conventional grower has a chemical seed treatment to prevent disease, but organic growers have had very few options and so it is not unusual to be forced to replant. At $1.30 per lb. and most peanut farmers planting over 100#’s per acre, cost add up quickly!

This growing season has had strange weather and because of that the test was planted later than wanted. Both air and soil temperatures jumped significantly in May meaning we needed to irrigate before planting – which created its own set of problems. It was hoped we could put these seeds into cold, wet soils to simulate a West Texas April/early May planting but sometimes things don’t work even in the best planning.  Even though it wasn’t ideal we saw a few differences that will help us to adjust what we do in the future for more testing. Listed below are the treatments and rates for the products tested. #7 and #10 serve as checks, #7 is bare seed and #10 is conventionally treated seed with Dynasty, Syngenta Co.  

Plots were 2 rows X 25’ with 100 seed planted per row or 4 seed per 1’ of row.  There were 4 replications of each plot, randomized. Planting date was May 20, 2022, into a previous irrigated site.  0.75 inches rain fell on May 23 and plots were sufficiently moist for good germination.  Peanut seed ‘crack’ was observed on May 26. 

Trt. #CompanyProductTrt.Per acre
1Ecological LaboratoriesQuantum-EXP 1IF64 oz/ac
2Summit AgroAVIVSeed10-30 oz/100-gallon water. Soak and dry
3Summit AgroAVIVIF10-30 oz/100-gallon water.
4Certis BioDouble NickelIFDouble Nickel LC @ 8 fl oz/acre
5Certis BioDouble NickelIFDouble Nickel LC @ 16 fl oz/acre
6American Plant FoodSigma 5-3-2 BioPPI1000 lbs./ac
7 NAUntreated CheckNA NA
8CortevaBexfondIF14 oz/ac
9ValentEndoPrime (EndoMaxx is organic of EndoPrime but not available at treatment)IF2oz/Ac
10 NATreated seed check NA NA

Looking at the results, there is no statistically significant difference in any of the treatments, but trends indicate some differences especially above the untreated check #7.  Overall, we want to improve both germination percentage and stand establishment with organic product treatments. Seed germination counts were done on May 31 and no further germination occurred.  Ratings of growth were done on June 3, 6, 9 and 13.  Rating scale was 1 – 4 with a 1 being best. Organic treatments 1, 2, and 4 were all rated above the untreated check #7. This gives us a possibility of further testing to see if they continue to show an advantage.

Trt. #CompanyProductTrtRateGerm. % 5/31Plot Rating
10 NATreated seed checkSeedDynasty powder52.8751.750
1Ecological Lab.Quantum-EXP 1IF64 oz/ac45.8571.875
2Summit AgroAVIVSeed10-30 oz/100-gallon water. Soak and dry43.7502.125
4Certis BioDouble NickelIFDouble Nickel LC @ 8 fl. oz/acre44.2502.188
7 NAUntreated Check NANA43.7502.438
3Summit AgroAVIVIF10-30 oz/100-gallon water.44.1252.563
8CortevaBexfondIF14 oz/ac35.5002.813
6American Plant FoodSigma 5-3-2 BioPPI1000 lbs./ac34.6253.063
9ValentEndoprimeIF2oz/Ac32.0003.125
5Certis BioDouble NickelIFDouble Nickel LC @ 16 fl. oz/acre37.2503.188
     Average2.513

“Beginner” Organic Training Class!

Okay, maybe this picture is not exactly a beginner organic class but by the next newsletter it could be you in the picture. I just love the one young boy off to the left, he is the future organic farmer!!

Mark it on your calendar, the first “Beginner Organic Training” program will be held on Tuesday, October 18 starting a 1pm and going through 5 pm, Wednesday, October 19 in Georgetown, Texas.  This “beginner” training program is really for anyone who has an interest in learning more about organic production, but it is certainly important and informational for those considering “the plunge” into certified organics.

Topics are being planned but include an overview of the Texas organic program, tour of a local organic nursery, soils and soil microbiome, cover crops for Texas, organic products & pest control, organic fertilizers, biostimulants and a compost tour, what’s involved in organic certification, beneficial insects in organic production and panel discussions.   Speakers include Extension Specialists, Texas Dept. of Ag. Organic Program, Extension Agents, Organic Producers, and more.     

We are working out the details for cost and a final agenda, but plans are to make it affordable, easy to participate, and fun to attend.  Put it on your calendar with more to come! If you are interested don’t hesitate to contact Kate Whitney, Williamson County Extension Horticulturist at (512) 943-3300.

Texas Organic Rice Production Guide

Texas organic rice acreage has steadily increased over the past decade, driven by increased market demand. Since 1995, organic rice acreage has increased in the U.S. by almost six-fold, with a majority of acreage being grown in the Southern U.S. The acreage in Texas alone reached more than 19,000 in 2022.

Texas has over 70 certified organic rice producers scattered from Beaumont to Victoria all along the Texas coast with a few just south of Houston – still! These producers sell to nearly a dozen different organic rice buyers and this rice makes its way into several Texas grocery chains.

What are the major issues facing organic rice producers? Fertility is a concern with almost every crop and rice is no exception. Using organic cover crops though can be a real benefit to rice producers supplying 60 to as much as 108 lbs of N to the subsequent rice crop. In rice these cover crops have to be incorporated early, as much as 4 weeks early, to prevent a strange condition known as straighthead. This extra time allows the cover crop to break down with little to no effect on the crop.

Another major issue is having good organic rice varieties. Fortunately we not only have great Texas A&M AgriLife rice breeders we also have an outstanding Rice Foundation Seed Program begun way back in the spring of 1941. As researchers develop new varieties, Foundation Seed makes those varieties available to rice farmers including organic rice farmers.

If you want to learn more about rice and the rice programs of Texas A&M Agrilife go to https://beaumont.tamu.edu. If you want to read the Texas Organic Rice Production Guidelines publication go to https://tinyurl.com/cdbz3fjd. And remember to eat Texas organic rice every chance you get!

Statewide Organic Training for USDA NRCS Personnel

This past week a nationwide planning team for organic agriculture training held the 2nd of four organic training programs for NRCS personnel in Texas. This planning team is made up of NRCS national and state leaders in organics, the National Center for Appropriate Technology, Texas Department of Agriculture and Texas A&M AgriLife Extension.

The training is being conducted online and is held from 9am to 2 pm for each of 3 days. In this first training there were 27 active trainees who learned about organic agriculture, organic certification and organizations and agencies that work in organic agriculture. There are many programs and services that NRCS offers to organic producers and this organic training will help your local NRCS folks know more about you, your production and how to help!

Organic Peanut Breeding at Texas A&M AgriLife

In the Texas A&M AgriLife Research peanut breeding program have 2 organic test locations this year. We put tests in locations across the state to be able to experience different conditions and to ensure we hopefully have some results if a whole test is wiped out!

In Vernon, Dr. Waltram Ravelombola, the statewide organic legume breeder is evaluating new breeding lines by collecting data using Unmanned Aerial Systems to evaluate emergence, seedling vigor, yield and grade across the season.  The lines being evaluated by Dr. Ravelombola represent the first year for evaluation of lines that were specifically bred for organic production. 

In addition, we are collaborating with Mr. Neil Froese on his farm in Gaines County for evaluation of similar traits in actual field level production scenarios.  This gives us an idea of how well breeding lines stand up to the pressure of sometimes unusual field conditions, weather, etc.