When choosing nozzles/droplet sizes for spray applications, applicators must consider both coverage needed and drift potential. As a rule, smaller droplets provide better coverage, but larger droplets are less likely to drift.

This fact sheet covers nozzle description, recommended use for common nozzle types, and orifice sizing for agricultural and turf sprayers. Proper selection of a nozzle type and size is essential for correct and accurate pesticide application. The nozzle is a major factor in determining the amount of spray applied to an area, uniformity of application, coverage obtained on the target surface, and amount of potential drift.

This extension publication discusses guidelines to quickly evaluate the performance of a sprayer. Sprayer calibration, nozzle discharge, spray pattern uniformity, speed checks, pump performance, and plumbing arrangements are evaluated with minimal calculations.

The Virginia Pest Management Guide (PMG) series lists options for management of major pests: diseases, insects, nematodes, and weeds. These guides are produced by Virginia Cooperative Extension and each guide is revised annually. PMG recommendations are based on research conducted by the Research and Extension Division of Virginia Tech, in cooperation with other land-grant universities, the USDA, and the pest management industry.

The Virginia Pest Management Guide (PMG) series lists options for management of major pests: diseases, insects, nematodes, and weeds. These guides are produced by Virginia Cooperative Extension and each guide is revised annually. PMG recommendations are based on research conducted by the Research and Extension Division of Virginia Tech, in cooperation with other land-grant universities, the USDA, and the pest management industry.

Pesticide sprays consist of at least 95% water. Water quality plays an important role in pesticide performance. The following issues may indicate a compatibility problem with pesticides and spray water quality: - Pesticide does not work at labeled rates; - Difficulty mixing sprays or clogging of nozzles; - Inconsistent pest control observed in fields or plots; - Pests seem resistant to a new pesticide active ingredient, or - Crops are lower quality or lower yielding. Understanding how water quality characteristics such as pH, water hardness, turbidity, and total suspended solids affect the adsorption and persistence (half-life, storage time) of a pesticide can help pesticide applicators reduce or eliminate compatibility issues and improve pesticide effectiveness

Mixing two or more pesticide products can allow for the treatment of several pests at the same time, improve pesticide performance, and ultimately saving time and money. However, physical and chemical tank mix incompatibilities can occur when combining two or more pesticides. Physical incompatibility is the failure of pesticide products to stay uniformly mixed and can result in layering, products settling out of solution, or clumping. A chemical incompatibility is the result of a chemical reaction between pesticide products. A chemical incompatibility is less visible and can be harder to detect. This publication focuses on basic factors that influence product compatibility (agitation speed and method, water temperature, mixing order, carrier type, and chemical formulations) and summarizes best mixing practices to address these factors.

Spray water problems may arise due to water quality and management decisions. Certain aspects of water quality can reduce the efficacy of the pesticide as well as affect how the pesticide interacts with the plant surface or targets pests. Evaluating and testing spray water chemistry can help identify water quality problems that might otherwise be overlooked. This publication will examine possible solutions to spray water problems, including the use of adjuvants and other additives to enhance pesticide performance.

Phosphorus is a naturally occurring element that is one of 16 elements essential for plant growth and animal health. Research has documented that applying phosphorus in fertilizers or manure increases crop growth and yield on soils that are below critical agronomic levels, as measured during routine soil testing. Although the economic benefits of phosphorus fertilization on crop production are well-documented, too much of a good thing can be detrimental to the environment. Excessive soil phosphorus is a potential threat to water quality.

Cankerworms are also known as inchworms, loop worms, and spanworms - this is credited to their distinctive way of moving. In order to travel, a cankerworm must grab leaves or branches with its front legs and then pull the rest of its body forward. This causes the abdomen area to contract and gives the worm the appearance of arching its back.

Internet websites and social media platforms often contain information that misguide the public in using homemade pesticides. The use of homemade pesticides is concerning for several reasons. Homemade pesticides do not have directions for safe handling and application, instructions on how to protect people, pets, plants, and the environment, and are often ineffective. This publication will explain what homemade pesticides are and how they differ from registered pesticides. It will also debunk several common myths about homemade pesticides.

Herbicides that are usually associated with contamination of straw/hay, turf clippings, manure, and composts are growth regulator herbicides or synthetic auxins, a group of herbicides that mimics plant hormones and regulates growth. These herbicides are labeled for control of broadleaf weeds in grass crops, such as pastures and corn; in turfgrass, including lawns, golf courses, parks, and highway turf; and in noncrop areas. Vegetable and fruit crops, as well as broadleaf ornamentals can inadvertently be injured by these chemicals through drift of spray droplets, volatilization, and spray tank contamination or by residues in straw, manure, turf clippings, or compost. Diagnosing the specific herbicide responsible for the plant damage can be difficult. This publication focuses on damage caused by herbicide residues.

The Eastern Shore Agricultural Research and Extension Center, Virginia Tech organized the Mid-Atlantic Spray Drone workshop on July 23-24, 2024 in Painter, VA. The workshop highlighted benefits of unmanned aerial systems (UAS), also known as aerial drones, emphasizing their role in crop protection and comparing efficacy and economics with traditional spraying methods. Over the two-day workshop, federal regulators, university researchers, industry personnel, and custom pesticide applicators (Figure 1) examined the current status of the technology, and debated drift issues, and management strategies. The workshop was attended by participants from Virginia, Delaware, Maryland, West Virginia, Pennsylvania, and New York.

VCE AG TODAY is a weekly webinar that provides updates on agricultural practices. If you have any questions, please reach out to your local Extension office or visit www.ext.vt.edu.