- Author: Hamutahl Cohen
Chlorpyrifos News: A Controversial Reversal
This November the Eighth Circuit Court of Appeals made a significant ruling overturning the Environmental Protection Agency's (EPA) ban on chlorpyrifos, an organophosphate pesticide. This decision marks a controversial turn in the ongoing debate surrounding the use of this pesticide and its potential impact on human health and the environment.
The history of the chlorpyrifos ban is a contentious one. The EPA had initially proposed banning the pesticide's use on food crops in 2015 due to concerns about its harmful effects, particularly on children and farmworkers. Studies and research had linked chlorpyrifos to developmental issues in children, neurodevelopmental delays, and other adverse health effects.
However, this ban faced several legal challenges from the agricultural industry, which argued that the scientific evidence against chlorpyrifos was not conclusive enough to justify a complete ban. Industry groups contended that the pesticide was essential for protecting crops from pests and ensuring food security.
The battle over chlorpyrifos intensified over the years, with the EPA under different administrations both moving toward and away from banning its use. In 2021, the EPA banned the pesticide, and upheld this ban in 2022. Now, the federal Eighth Circuit Court of Appeals has overturned the EPA ban, which has sparked renewed discussions. The court's decision was based on its interpretation that the EPA had not provided enough evidence to justify the ban, stating that the agency had not sufficiently demonstrated that the pesticide's residues on food posed a risk to human health. Note that some states, including California, have banned chlorpyrifos on food grown and sold in their jurisdictions. Those bans remain in effect.
This reversal has generated mixed reactions. Advocates for agricultural interests and some in the industry welcome the decision, emphasizing the importance of chlorpyrifos in protecting crops. On the other hand, environmentalists, public health experts, and concerned citizens express disappointment about the potential health hazards posed by continued use of the pesticide. This debate highlights the complex balancing act between agricultural needs, economic interests, and public health concerns.
Argentine ant is a problem in citrus
- Author: Ben Faber
Key to the Phytoseiid Predatory Mites Found on California Crops
Key to the Phytoseiid Predatory Mites Found on California Crops
Predatory mites in the family Phytoseiidae are known throughout the world in agricultural crops as important predators of pest mites, especially the spider mites (Tetranychidae), as well as small insects such as thrips, psyllids, scales, aphids, and whiteflies.
Detailed line drawings illustrate descriptions of each mite species, and a separate appendix included in the download contains photos of key characteristics of slide-mounted mites taken through a compound microscope. The interactive appendix, includes photos of forty-five of the forty-six mite species found in the key.
For the majority of mite species, photos of the dorsum, venter, ventrianal shield, spermatheca, and chelicera are provided. For some species, additional photos are included for structures that are especially important for confirming identification, such as the peritreme, macrosetae, pores, and dorsal shield indentations.
This free publication is available by download. The publication and the appendix are included in a zip file. Please note this is a large, 36MB file
This publication is best viewed using the free Adobe® Acrobat® Reader. You can download a free copy of the Acrobat Reader from Adobe Systems Incorporated.
Airblast sprayers are the most used equipment for pesticide application in perennial specialty crops in the San Joaquin Valley and across California. The application involves applying spray from both sides of the sprayer onto tree or vine canopies, as an operator drives the sprayer between tree/vine rows. Airblast sprayers use a fan to produce air intended to carry the spray to the target. The air also helps the spray droplets to penetrate the target canopies to deposit deep inside the canopy.
Good or Bad Air?
A critical consideration for any application is the amount of air needed to carry the spray to the target. How much air is too little? How much is adequate? How much is too much? There is a tendency to assume that more air always means better effectiveness, but one size does not fit all. So, the air can either work for or against effectiveness. Use too little air and the spray will not penetrate sufficiently. Use too much, and the spray will be excessively pushed through the canopy. Using the right amount of air will require making intentional adjustments during sprayer calibration and properly documenting the settings for future reference.
Find out the rest of the story:https://ceventura.ucanr.edu/newsletters/Topics_in_Subtropics99392.pdf
- Author: Mark Battany
Coastal California crops include many which are sensitive to frost, including grapes, strawberries, avocado and citrus. Our primary active protection measures are water and wind; water for sprinkler frost protection is very effective in many situations, but the scarcity and high cost of water is making it increasingly difficult to justify, and the high rates of water application can degrade crop quality in some situations. Wind machines are therefore gaining increasing attention as an attractive alternative where conditions permit their use.
Wind machines generate a warming benefit primarily by mixing the warmer air aloft with the colder air near the crop. This situation of having warmer air aloft and colder air near the ground surface is termed a temperature inversion. Temperature inversions tend to form under nighttime conditions of clear skies and little to no wind; these are the typical conditions which drive a radiation frost. The cloudier and/or windier the nighttime conditions, the weaker the inversions. Under advective frost conditions, the air temperature aloft may actually be colder than near the ground; clearly under such conditions the operation of wind machines can be detrimental to the crop, hence the importance to have some understanding of the patterns of temperature inversions in our growing regions.
Measurements of the temperature inversion can be used in two fundamental ways. Firstly, as part of a site assessment, to help determine whether or not wind machines may be suitable for use at the site. Secondly, to help guide decisions of whether or not to utilize wind machines during a particular frost event. For the former, measurements can be made with inexpensive data loggers which store the values for later evaluation well after the frost period. For the latter, a more expensive weather station which can provide real-time data to users will be required.
Get the full story at: https://ceventura.ucanr.edu/newsletters/Topics_in_Subtropics99392.pdf
Utilizing the Arthropod Pesticide Resistance Database
Growers face the daunting challenge of managing several pests that exhibit pesticide resistance. In this battle, selecting appropriate pesticides play a crucial role. We know that pesticide resistance is a phenomenon in which certain pest populations develop the ability to withstand the effects of pesticides that were once effective against them. This resistance can occur due to the natural genetic variability within pest populations and is exacerbated by the overuse or misuse of specific pesticides. To prevent or mitigate pesticide resistance, growers can alternate pesticides with different modes of action. This approach involves periodically switching between pesticides that target pests using different biological mechanisms, making it more challenging for pests to develop resistance to all of them. By diversifying the pesticides they use, growers reduce the selective pressure on a single mode of action, slowing down the development of resistance To make informed decisions, agricultural experts can utilize resources such as UC ANR's pest and pesticide recommendations. Another useful tool I just learned about is the Arthropod Pesticide Resistance Database, available at https://www.pesticideresistance.org/. This resource serves as a comprehensive repository of information related to arthropod pesticide resistance.
The Arthropod Pesticide Resistance Database offers a wealth of data on resistance in various arthropod species, such as insects, mites, and ticks. Users can access information about the resistance mechanisms, geographical distribution, and the latest research findings on pesticide resistance in these pests. To use the database effectively, users can search for specific pests or pesticide. Users can utilize the database to identify regions where resistant pest populations are more prevalent, allowing them to tailor their pest management strategies accordingly. What strikes me as fascinating is the availability of data from around the globe. By understanding which pesticides are still effective and which ones may need to be used sparingly or replaced with alternative methods, farmers can make more sustainable and cost-effective choices to protect their crops. Have you used this resource before to make decisions or learn about a pest and it's control? I'd love to hear from you at hcohen@ucanr.edu
