Resources for Plant Diseases

Title Available As Summary Date ID Author
Bacterial Leaf Scorch of Landscape Trees Dec 7, 2018 3001-1433 (SPES-83NP)
Soybean Rust Incidence and the Response of Soybeans to Fungicides in 2009 Dec 21, 2010 3012-1520
Successful No-Tillage Corn Production Mar 20, 2019 424-030
Supermarkets as Alternative Market Outlets for Virginia-Grown Berries
Plant Disease Diagnostic Form
Sep 22, 2021 450-097 (SPES-261NP)
Problem-free Shrubs for Virginia Landscapes
The most effective form of plant disease control in the landscape is prevention. Disease prevention can be as simple as choosing the right plant for the right place at planting time. This fact sheet was developed as a guide to shrubs that generally experience few problems in Virginia landscapes. Using these species for new plantings should help you avoid troublesome disease and insect problems in your landscape.
Jun 27, 2016 450-236 (PPWS-69P)
Problem-free Trees for Virginia Landscapes
Many of the tree species commonly planted in Virginia landscapes suffer from disease problems. Although some diseases can be cured, most must be controlled on a preventative basis. The best option for new plantings is to choose species that have a low risk of developing disease. Listed below, in alphabetical order, are some choices of problem-free trees for Virginia landscapes.
Oct 19, 2016 450-237 (PPWS-70P)
Iris Leaf Spot
Iris leaf spot (also called Heterosporium leaf spot) is the most common disease of iris in Virginia. It is caused by the fungus Cladosporium iridis (syn. Heterosporium iridis). Leaf spotting is most conspicuous on the upper half of the leaf following bloom. Although this pathogen is most common on bulbous iris, it can also cause severe damage to rhizomatous iris, and has also been reported on Gladiolus, Freesia and Narcissus species.
Nov 2, 2021 450-600 (PPWS-90NP)
Juniper Tip Blights Mar 30, 2017 450-601 (PPWS-91 NP)
Leaf and Flower Gall of Azalea and Camellia
Leaf and flower gall is a disease that is common on azaleas and camellias in the spring. The disease has also been reported on other members of the plant family Ericaceae. It occurs in home landscapes and nurseries, and is often seen on flame azaleas in the forest in the spring. The disease is caused by species of the fungus Exobasidium.
Oct 18, 2016 450-605 (PPWS-92NP)
Anthracnose on Snap Beans
Anthracnose is a major disease of the common snap bean (Phaseolus vulgaris) and can occur on other legumes. It is caused by the fungus Colletotrichum lindemuthianum. When environmental conditions are favorable, crop losses can be as high as 100 percent on susceptible cultivars of snap beans.
Jul 30, 2019 450-719 (SPES-157NP)
Brown Rot on Peach and Other Stone Fruits
Brown rot is one of the most destructive diseases of peach and nectarine in Virginia, and also occurs on other stone fruits such as apricot, cherry, and plum. When environmental conditions favor this disease, crop loss can be devastating.
Mar 18, 2020 450-721 (SPES-24P)
Reducing Pesticide Use in the Home Lawn and Garden
Pesticide use affects the quality of human health, the environment, and nontarget organisms in the ecosystem. Therefore, any pesticide application warrants a careful assessment of the expected benefits and risks. Too often, however, homeowners use pesticides inappropriately or without careful consideration of alternatives. This fact sheet outlines general pest control tactics that can easily be implemented for home lawns and gardens, along with other information that home owners can use to make sound pest management decisions. The intent is to ensure that homeowners are aware of alternative control tactics and pesticide characteristics, and that pesticides are used properly and only when necessary.
Sep 11, 2018 450-725 (SPES-22P)
Botryosphaeria Canker and Dieback of Trees and Shrubs in the Landscape
Most trees and shrubs are susceptible to dieback and cankers caused by several species of the fungal genus Botryosphaeria. Botryosphaeria fungi are typically opportunistic pathogens. Opportunistic pathogens only cause disease on plants that are stressed. Therefore, avoiding plant stress, which predisposes plant tissue to infection and colonization by this fungal group, is the best strategy to prevent Botryosphaeria disease problems.
Mar 18, 2020 450-726 (SPES-23P)
2022 Pest Management Guide - Field Crops Feb 3, 2022 456-016 (ENTO-461P)
2022 Pest Management Guide - Home Grounds and Animals
This 2022 Virginia Pest Management Guide provides the latest recommendations for controlling diseases, insects, and weeds for home grounds and animals. The chemical controls in this guide are based on the latest pesticide label information at the time of writing. Because pesticide labels change, read the label directions carefully before buying and using any pesticide. Regardless of the information provided here, always follow the latest product label instructions when using any pesticide.
Feb 11, 2022 456-018 (ENTO-462P)
Virginia Master Naturalist, Basic Training Course, Botany
Plants can be defined as multicellular, photosynthetic organisms with reproductive structures that are more complex than single cells. By this definition, algae are not considered plants because they are either unicellular or their reproductive structures are essentially unicellular. Fungi, too, are excluded because they are not photosynthetic. At least 400 million years of diversification have resulted in a wide diversity of taxonomically distinct major groups of plants. Some of the most important groups of plants found in Virginia are described below.
Jul 19, 2019 ANR-10NP (CNRE-62NP)
Virginia Master Naturalist, Basic Training Course, Botany (Introductory Version)
Plants can be defined as multicellular photosynthetic organisms with reproductive structures that are more complex than single cells. By this definition, algae are not considered plants because they are either unicellular or their reproductive structures are essentially unicellular, and fungi, too, are excluded because they are not photosynthetic.
Jul 19, 2019 ANR-12NP (CNRE-63NP)
Commercial Chinese Chestnut Production in Virginia Sep 21, 2017 ANR-279P
Late Blight of Tomato and Potato Nov 20, 2018 ANR-6 (SPES-72P)
Galls and Rust made by Mites
Galls are abnormal growths of plant tissue induced by insects and other organisms. Gall-making parasites release growth-regulating chemicals as they feed, causing adjacent plant tissues to form a gall. The parasite then develops within the relative security of the gall. Galls come in an endless variety of forms. Many are strikingly colored or curiously shaped. Each gall-making species causes a gall structurally different from all others. By noting the type of host plant and the structure of the gall, one can identify the gall-making mite without actually seeing it.
May 8, 2015 ENTO-147NP
Integrated Pest Management of Hemp in Virginia Mar 2, 2020 ENTO-349NP
Best Management Practices for Boxwood Blight in the Virginia Home Landscape
This Best Management Practice document is a set of guidelines for home growers of landscape boxwood to avoid introduction of the boxwood blight pathogen into a landscape or, if the disease is already present in a landscape, to manage the disease in the most effective manner and avoid spread of the disease to new locations.
Jan 5, 2021 PPWS-29NP (PPWS-85NP)
Virginia Boxwood Blight Task Force
To provide leadership in safeguarding and protecting the ornamental horticulture industry, historical gardens and landscape plantings from boxwood blight.
Jul 1, 2019 PPWS-30
Best Management Practices for Boxwood Blight in Virginia Production Nurseries WITH Boxwood Blight
This Best Management Practice document is a set of guidelines for home growers of landscape boxwood to avoid introduction of the boxwood blight pathogen into a landscape or, if the disease is already present in a landscape, to manage the disease in the most effective manner and avoid spread of the disease to new locations.
Feb 16, 2021 PPWS-32NP (PPWS-87NP)
Best Management Practices for Boxwood Blight in Virginia Production Nurseries WITHOUT Boxwood Blight Version 2, September 2016
This Best Management Practice document is a set of guidelines for home growers of landscape boxwood to avoid introduction of the boxwood blight pathogen into a landscape or, if the disease is already present in a landscape, to manage the disease in the most effective manner and avoid spread of the disease to new locations.
Jan 5, 2021 PPWS-33NP (PPWS-86NP)
Best Management Practices for Boxwood Blight: Best Management Practices for Virginia Retail Nurseries WITH Boxwood Blight
This Best Management Practice document is a set of guidelines for home growers of landscape boxwood to avoid introduction of the boxwood blight pathogen into a landscape or, if the disease is already present in a landscape, to manage the disease in the most effective manner and avoid spread of the disease to new locations.
Jan 6, 2021 PPWS-34NP (PPWS-89NP)
Best Management Practices for Boxwood Blight: Best management Practices for Virginia Retail Nurseries WITHOUT Boxwood Blight
This Best Management Practice document is a set of guidelines for home growers of landscape boxwood to avoid introduction of the boxwood blight pathogen into a landscape or, if the disease is already present in a landscape, to manage the disease in the most effective manner and avoid spread of the disease to new locations.
Jan 6, 2021 PPWS-35NP (PPWS-88NP)
Best Management Practices for Boxwood Blight for Greenery Producers
Best management practices for boxwood blight (also called “box blight”) for greenery producers are practices recommended to avoid the introduction and spread of boxwood blight, caused by the fungus Calonectria pseudonaviculata (syn. Cylindrocladium pseudonaviculatum). The recommendations in this document are designed to avoid spread of boxwood blight within a planting or to new locations when pruned tips are collected, sold and/or used for holiday greenery1. These recommendations are relevant to anyone involved in the greenery (“tipping”) industry, including small and large-scale greenery producers, home growers who sell boxwood tips, and people who tip-prune boxwood on other people’s property. Care must be taken at all levels of greenery production to prevent the spread of the boxwood blight pathogen and avoid economic losses associated with this disease.
Jan 6, 2021 PPWS-39NP (PPWS-95NP)
Nematode Management in Field Crops May 17, 2018 SPES-15
Mortality of Great Rhododendron (Rhododendron maximum) in Virginia
Since 2015, Extension specialists from Virginia Tech (VT) have visited and collected plant and soil samples from several large areas of dying great rhododendron (Rhododendron maximum) in Virginia’s mountainous regions. In 2016 VT specialists met with Virginia Department of Forestry, US Forest Service personnel, and other experts to revisit some of these sites. No consistent cause of this mortality has yet been identified. It is possible that a variety of factors are stressing the rhododendrons in these areas to a point where opportunistic pathogens or insects can successfully attack and kill them. The following information summarizes our observations and diagnostic results from four separate great rhododendron mortality sites in Virginia. This information is not equivalent to a research study, which would also include samples taken from healthy great rhododendron for comparison; however, we are confident that we have ruled out two diseases that are frequently mentioned both online and anecdotally as a cause of this mortality, specifically Phytophthora root rot and Botryosphaeria dieback.
Aug 21, 2019 SPES-151P
Instructions for Sampling and Submitting Crop Nematode Samples May 17, 2018 SPES-16NP
Fusarium Wilt of Mimosa (Albizia julibrissin) Aug 13, 2020 SPES-230NP
2020 Virginia Tech Eastern Shore AREC Virtual Research Field Day Aug 17, 2020 SPES-239NP(SPES-243NP)