New Paraquat Requirements

Pesticide testing.

This 2-page document addresses the mitigation measures being undertaken by the EPA which will become new labeling requirements for paraquat (one of the most widely used herbicides registered in the United States) products. Written by Frederick M. Fishel and published by the UF/IFAS Agronomy Department, November 2018.
http://edis.ifas.ufl.edu/pi279

Using Dicamba in Dicamba-Tolerant Crops

Chipley, Florida, farm, harvest, October, Washington County, cotton, combine. UF/IFAS Photo: Josh Wickham.

After many years in development, dicamba will likely be fully approved for use in tolerant cotton varieties for the 2017 growing season. There is great concern that dicamba drift can result in significant losses in nearby sensitive crops. This concern is well-founded because many crops (such as soybean, snap bean, and peanut) are highly sensitive to extremely low doses of dicamba. All precautions must be followed if these new dicamba formulations are to be used. This 3-page fact sheet discusses herbicide selection, discontinued use of ammonium sulfate, nozzle selection, boom height, and wind speed. It also addresses a few frequently asked questions. Written by J. Ferrell and R. Leon, and published by the UF Agronomy Department, February 2017.
http://edis.ifas.ufl.edu/ag414

Herbicides to Kill Invasive Trees in Home Landscapes and Surrounding Natural Areas

A single-nozzle backpack sprayer is useful for foliar treatment of many woody invasive plants.

Several plant species that are invasive in natural areas of public lands also occur on private property. Invasive plants on private property that thrive within both landscaped and surrounding natural areas can serve as a source of infestation to other natural areas. Therefore, property owners are encouraged to remove invasive plant species from both areas. This 5-page fact sheet is a major revision that discusses different herbicides, hand-pulling, stump grinding, foliar herbicide application, cut stump herbicide application, basal bark herbicide application, hack-and-squirt, frill, or girdle herbicide application, licenses and training, and control of specific invasive plants. Written by K. A. Langeland and S. F. Enloe, and published by the UF Department of Agronomy, revised May 2016.
http://edis.ifas.ufl.edu/ag259

Metsulfuron-Methyl-Containing Herbicides Potentially Damaging Ornamentals when Applied to Turfgrass

Figure 1. Phloem necrosis shown as streaking brown sections of wood exposed by peeling the bark back in a live oak (Quercus virginiana) branch affected by metsulfuron-methyl. Credits: Jason Smith, UF/IFAS
Metsulfuron-methyl, also known as MSM, is an herbicide that is used to control broadleaf weeds and certain grass weeds. It provides effective control of some of the most problematic turfgrass weeds, such as wild garlic, Florida betony, dollar weed, and small Virginia buttonweed. Metsulfuron-methyl is absorbed by plant foliage, so if landscape plants come into contact with the spray or drift they can be injured. This four-page fact sheet describes the potential problems with metsulfuron herbicides, the areas most subsceptible to damage, how to diagnose injury, and how to reduce damage. Written by Chris Marble, Jason Smith, Timothy K. Broschat, Adam Black, Ed Gilman, and Celeste White and published by the School of Forest Resources and Conservation Department.
http://edis.ifas.ufl.edu/fr400

Turfgrass Herbicides: Mechanisms of Action and Resistance Management

Turfgrass

Herbicides are an effective tool for controling weeds in turfgrass; however, weeds can become resistant to herbicides and create significant problems for turfgrass production. The best way to combat herbicide resistance is to rotate herbicides with different mechanisms of action (MOA) because using herbicides with different MOAs makes it more likely that weeds resistant to one herbicide will encounter an herbicide to which they are not resistant. This 4-page fact sheet focuses on how to create an herbicide program that uses different MOAs to manage resistant weeds. Written by Ramon G. Leon and Bryan Unruh, and published by the UF Department of Agronomy, August 2015.
http://edis.ifas.ufl.edu/ag398

Calibration of Chemical Applicators Used in Vegetables (HS1220)

Figure 2. A nozzle includes the nozzle body, strainer, core, disc, and nozzle cap.Calibration is the process used to determine the amount of chemical material applied per unit area. Equipment for applying liquid and dry materials must be accurately calibrated for pesticides to work efficiently and to avoid crop injury or death. The pesticide label is a legal document and must be followed. Properly calibrating equipment ensures the product is being applied as specified on the label and that environmental contamination will be minimized. This 6-page fact sheet discusses some methods for calibration of sprayers and dry material spreaders and includes information about calibration to help growers properly apply pesticides. written by M. R. Miller and P. J. Dittmar, and published by the UF Department of Horticultural Sciences, May 2013.
http://edis.ifas.ufl.edu/hs1220

Factors Affecting Herbicide Use in Fruits and Vegetables (HS1219)

HS1219Proper herbicide application is critical for fruit and vegetable growers to effectively manage weeds. Improper herbicide application may lead to herbicide loss from the targeted area, increased crop injury, and reduced weed control. Growers need to take into account a number of factors before and during application in any crop to ensure the herbicide is effective. Herbicide efficacy is greatly affected by timing and environmental conditions. Although complete weed control is not always possible, even slight reductions in weed populations can greatly enhance productivity in fruit and vegetable crops. This 4-page fact sheet reviews techniques and processes to help growers properly apply herbicides. Understanding the processes and applying the following techniques will help to increase the overall efficacy of herbicides in fruit and vegetable production. Written by C. E. Rouse and P. J. Dittmar, and published by the UF Department of Horticultural Sciences, May 2013.
http://edis.ifas.ufl.edu/hs1219

Storage Limitation Statements: Temperature – Herbicides (PI123/PI160)

Figure 1. Pesticide drum bulging from extreme heat.This 8-page guide provides information about how temperature affects storage of agricultural herbicides. A table is included that lists many common agricultural herbicides registered for use in Florida, with storage limitation statements. Written by Frederick M. Fishel, and published by the UF Department of Agronomy, April 2013.
http://edis.ifas.ufl.edu/pi160

Rainfast Time for Postemergence Herbicides Commonly Used in the Everglades Agricultural Area: Quick Reference Sheet (SSAGR351/AG359)

measuring water quality in a canalIf rainfall occurs soon after herbicide application, it can affect the effectiveness of postemergence herbicides. And they each differ in their time requirements for rain-free periods following application. This 2-page fact sheet shows rainfast time for postemergence herbicides commonly used in the Everglades Agricultural Area for sugarcane and vegetable production. Written by D.C. Odero and published by the UF Department of Agronomy, August 2011. (Photo by Eric Zamora UF/IFAS)
http://edis.ifas.ufl.edu/ag359

PI123/PI160 Storage Limitation Statements: Temperature – Herbicides

Revised! PI-123, a 10-page illustrated guide by Frederick M. Fishel, provides general temperature effects on storage properties of agricultural herbicides. A table is included that lists many of the common agricultural herbicides registered for use in Florida, with storage limitations statements. Includes references. Published by the UF Department of Agronomy, October 2009.
http://edis.ifas.ufl.edu/PI160