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Plant Pathology, Physiology and Weed Science

Title Summary Date ID Author(s)
2011 Peanut Variety and Quality Evaluation Results - Quality Data Aug 28, 2012 AREC-6
2011 Peanut Variety and Quality Evaluation Results, Agronomic and Grade Data Jan 9, 2012 AREC-5
2012 Peanut Variety and Quality Evaluation Results - Agronomic and Grade Data Jan 16, 2013 AREC-32NP
2013 Peanut Variety and Quality Evaluation Results - Agronomic and Grade Data Jan 16, 2014 AREC-64NP
2013 Peanut Variety and Quality Evaluation Results - II. Quality Data Mar 14, 2014 AREC-85NP
2016 Mid-Atlantic Commercial Vegetable Production Recommendations Jan 29, 2016 456-420 (AREC-168NP)
APS Potomac Division Meeting Sep 7, 2011
AREC-Ag Industry Tour Sep 7, 2011
Agronomy Handbook, 2000 May 1, 2009 424-100
Alumni Spotlight Sep 7, 2011
Anthracnose on Snap Beans Jan 29, 2014 450-719 (PPWS-26NP)
Asian Soybean Rust - Frequently Asked Questions I: Background and General Information May 1, 2009 450-301
Asian Soybean Rust - Frequently Asked Questions II: Identification, Biology, and Ecology May 1, 2009 450-302
Asian Soybean Rust - Frequently Asked Questions III: Control with Fungicides May 1, 2009 450-303
Asian Soybean Rust - Frequently Asked Questions IV: Cropping Systems and Cultural Practices May 1, 2009 450-304
Asian Soybean Rust - Frequently Asked Questions V: Monitoring, Tracking, and Scouting May 1, 2009 450-305
Awards, Scholarships, and Recognition Sep 7, 2011
Bacterial Leaf Scorch of Landscape Trees Jan 11, 2010 3001-1433
Bean Pod Mottle Virus in Virginia Soybeans Sep 9, 2010 3009-1461
Best Management Practices for Bioenergy Crops: Reducing the Invasion Risk Jan 5, 2012 PPWS-8P
Best Management Practices for Boxwood Blight for Greenery Producers Oct 13, 2016 PPWS-39NP (PPWS-95NP)
Best Management Practices for Boxwood Blight for Professionally Managed Landscapes and Public and Historic Gardens in Virginia

Boxwood blight is caused by the fungal pathogen Calonectria pseudonaviculata (syn. Cylindrocladium buxicola). Boxwood blight was first described in the United Kingdom in the mid-1990’s and by 2002 was found in several other European countries and New Zealand. In September 2011 boxwood blight was discovered in North America. Symptoms of the disease include leaf spotting (Fig. 1), elongate, dark cankers on stems (Fig. 2), defoliation, and dieback (Fig. 3). The primary means by which the disease spreads is the inadvertent introduction of infected boxwood to existing plantings. The pathogen can also spread by spores, which readily adhere to equipment and work clothes, and by microsclerotia, which survive in infested soil and plant debris. This document outlines best management practices for landscapers and property managers to reduce the risk of spreading boxwood blight to landscapes and public and historic gardens, and to manage the disease if it is introduced.

Sep 26, 2016 PPWS-49NP (PPWS-84NP)
Best Management Practices for Boxwood Blight in Virginia Production Nurseries WITHOUT Boxwood Blight Version 2, September 2016

Boxwood blight (also known as box blight), caused by the fungus Calonectria pseudonaviculata, is a serious fungal disease of boxwood that results in defoliation and decline of susceptible boxwood. In Virginia boxwood blight was first identified in a nursery location in Carroll County in 2011. By the fall of 2013 it was found in other commercial nursery/retail operations and landscapes in several counties in Virginia

Sep 30, 2016 PPWS-33NP (PPWS-86NP)
Best Management Practices for Boxwood Blight in the Virginia Home Landscape: Version 2, September 2016 Sep 30, 2016 PPWS-29NP (PPWS-85NP)
Best Management Practices for Boxwood Blight: Best management practices for Virginia retail nurseries WITH boxwood blight Version 2, August 2016 Sep 30, 2016 PPWS-34NP (PPWS-89NP)
Best Management Practices for Boxwood Blight: Best management practices for Virginia retail nurseries WITHOUT boxwood blight Version 2, September 2016 Sep 30, 2016 PPWS-35NP (PPWS-88NP)
Best Management Practices for Boxwood Blight: Best management practices for boxwood blight in Virginia production nurseries WITH boxwood blight Version 2, September 2016 Sep 30, 2016 PPWS-32NP (PPWS-87NP)
Botryosphaeria Canker and Dieback of Trees and Shrubs in the Landscape Mar 16, 2015 450-726 (PPWS-50)
Botrytis Blight of Peony Sep 26, 2016 450-602 (PPWS-93NP)
Boxwood Blight: A New Disease of Boxwood Found in the Eastern U.S. Jan 5, 2012 PPWS-4
Brown Rot on Peach and Other Stone Fruits Mar 25, 2015 450-721 (PPWS-64P)
Common Diseases of Soybean in the Mid-Atlantic Region

Common diseases of soybean are caused by viruses, bacteria, fungi and nematodes. Some diseases are spread by insect vectors and nematodes while others are spread by wind, splashing rain, or movement in soil. The best way to determine if disease control would be profitable is to first identify the diseases that are capable of causing  conomic yield losses. Symptoms of disease include plant damage caused by a pathogen and the reaction of plants to infection. Signs are the visible evidence of the pathogen. Some diseases have characteristic symptoms and signs that are identifiable in the field.

Feb 17, 2010 3001-1435
Control of Common Pasture and Hayfield Weeds in Virginia and West Virginia

Annual and perennial weed control in pastures and hayfields is an important aspect of successful forage management. This publication will discuss control measures for many of the common weeds found in Virginia and West Virginia permanent fescue and mixed fescue / bluegrass / orchardgrass pastures and hayfields.

May 1, 2009 427-002
Corn Smut May 1, 2009 450-706
Cost and benefit of seed treatments and Temik 15G in furrow for seedling disease and nematode control in Virginia, 2008 Nov 19, 2009 2911-1419
Entomosporium Leaf Spot of Photinia

Photinia, a shrub belonging to the plant family
Rosaceae, is a popular landscape shrub in the
southeastern U.S. Several species are grown, but
the most popular is the hybrid Photinia ×fraseri, or
“redtip”, so named for its bright red, immature foliage.
The biggest drawback to growing photinia is a leaf
spot disease caused by the fungus Diplocarpon mespili
(syn. Entomosporium mespili) to which redtip is
highly susceptible.

Sep 30, 2016 450-609 (PPWS-82P)
Environmental Best Management Practices for Virginia's Golf Courses Feb 27, 2013 ANR-48NP
Faculty and Staff Updates Sep 7, 2011
Fall Lawn Care
The fall season is an important transition period of turfgrass growth and development, and the management of your warm- and cool-season grasses at this time of year means a great deal in terms of anticipated success in your lawn the following spring.
Jul 2, 2015 430-520(CSES-109P)
Farm Security - “Treat it Seriously” – Security for Plant Agriculture: On-Farm Assessment and Security Practices

Acts of terrorism have heightened our awareness of the need for increased personal and farm security. The greatest security risk to farms, greenhouses and nurseries where plants are grown is the unauthorized access to farm chemicals and application equipment.

Mar 9, 2011 445-005
Fusarium Wilt of Mimosa (Albizia julibrissin)

Fusarium wilt is a common and lethal disease of mimosa (Albizia julibrissin)1, also commonly known as silktree. In the United States this disease occurs in the east from New York southward and also in Louisiana, Arkansas and California. Fusarium wilt is caused by the fungus Fusarium oxysporum forma specialis perniciosum. Albizia spp. are the only known host of F. oxysporum'' f.sp. ''perniciosum''. Fusarium oxysporum f. sp. perniciosum colonizes and clogs the tree’s vascular (water-conducting) tissue, and interferes with the movement of plant sap. This results in relatively rapid tree death.

Jan 20, 2015 2811-1020(PPWS-53NP)
Gray Leaf Spot Disease of Corn May 1, 2009 450-612
Greetings – Welcome to the annual PPWS newsletter! Sep 7, 2011
Growing 'Titan': A Large-Seeded, Virginia-Type Peanut for Specialty Markets Jun 18, 2013 AREC-42P
Growing Bread Wheat in the Mid-Atlantic Region

The more than 55 million people who live in the mid-Atlantic region of the United States want to purchase processed grain foods such as bread and other dough products made from hard, or bread, wheat. 

May 1, 2009 424-024
Growing Hulless Barley in the Mid-Atlantic May 1, 2009 424-022
Identification and Control of Annual Ryegrass in No-Till Corn in Virginia

In Virginia, annual ryegrass has become one of the most troublesome and difficult to control weeds in small grains, as well as in corn and soybeans grown in rotation with small grains. Annual ryegrass control has declined due to the development of resistance to Hoelon, which has been the only treatment available for control in wheat and barley. Lack of control in small grains has allowed annual ryegrass to proliferate and become problematic in no-till corn establishment where high rates of triazine herbicides or sequential applications of nonselective herbicides are frequently required for acceptable control.

May 1, 2009 427-001
Identification and Control of Hemp Dogbane (Apocynum cannabinum L.) in Virginia May 1, 2009 450-140
Identification and Control of Honeyvine Milkweed (Ampelamus albidus (Nutt.) Britt.) in Virginia May 1, 2009 450-139
Identification and Control of Horsenettle (Solanum carolinense L.) in Virginia May 1, 2009 450-142
Identification and Control of Mugwort (Artemisia vulgaris L.) in Virginia May 1, 2009 450-141
Identification and Control of Trumpetcreeper (Campsis radicans (L.) Seem ex Bureau) in Virginia May 1, 2009 450-143
Impact of Cotton Monoculture, Variety Selection, and Chemical Inputs on Disease Control, 2011 Jan 27, 2012 AREC-13
Impatiens Downy Mildew May 21, 2013 PPWS-19NP
Integrated Pest Management for Plant Diseases in the Home Garden and Landscape, Learning Module I: Integrated Pest Management Apr 22, 2015 PPWS-14NP
Integrated Pest Management for Plant Diseases in the Home Garden and Landscape, Learning Module II: The Plant Disease Triangle Apr 22, 2015 PPWS-15NP
Intensive Soft Red Winter Wheat Production

New and successful techniques have been developed for intensive soft red winter wheat management by a multidisciplinary research and Extension team at Virginia Tech. Research was started in the early 1980's and continues today. The guidelines presented in this manual and the accompanying videotape are based on that research.

May 1, 2009 424-803
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

Nov 1, 2016 450-600 (PPWS-90NP)
Itchgrass Identification and Control in Virginia

On October 3, 2007, the Weed Identification Clinic at Virginia Tech received an itchgrass [Rottboellia cochinchinensis (Lour.) Clayton] sample from a cornfield in Westmoreland County, near Montross (Figure 1). Currently, itchgrass is considered a federal noxious weed and the Westmoreland County sample is the first record of this plant in the state of Virginia.

May 1, 2009 427-008
Juniper Tip Blights

In Virginia, juniper tip blight is caused by one of
two different fungi, Phomopsis juniperovora or
Kabatina juniperi. Symptoms of the two diseases
are identical; however, some aspects of their control
differ. Therefore, correct identification of the causal
agent is important. These fungi can also attack other
hosts, including Cryptomeria, Chamaecyparis, and
Thuja species. They seldom cause significant damage
in landscapes unless weather conditions become
favorable for disease development. However, they
can be very destructive in seedbeds, cutting beds,
and lined-out stock in nurseries, or in mass landscape
plantings that receive overhead irrigation.

Jan 27, 2017 450-601 (PPWS-91NP)
Late Blight of Tomato and Potato Jan 20, 2012 ANR-6
Lawn Moss: Friend or Foe?

There are thousands of species of moss worldwide. These very simple plants lack the typical leaf, shoot, root, and seed-forming systems of most higher plants; however, they are some of the hardiest living organisms on the planet (Figure 1). Lawn moss can reproduce sexually (spores, etc.) or asexually (breaking off into smaller pieces that divide and multiply), and their numbers can increase rapidly under the right conditions. They are tolerant of extremely low mowing, so regular clipping of the grass will not remove them. It would seem that these plants would not offer much resistance to our efforts to manage or control them, but as Mother Nature often shows, their simplicity in design and function correlates well with their ability to colonize and persist in some of the most inhospitable growing conditions around your property: sidewalks, driveways, and yes – the lawn.

May 1, 2009 430-536
Leaf and Flower Gall of Azalea and Camellia Oct 18, 2016 450-605 (PPWS-92NP)
Maintenance Calendar for Cool-Season Turfgrasses in Virginia Feb 3, 2016 430-523 (CSES-153NP)
Maintenance Calendar for Warm-Season Lawns in Virginia Feb 25, 2016 430-522 (CSES-152P)
Managing Fusarium Head Blight in Virginia Small Grains

Fusarium head blight (FHB), or scab, continues to impact small grain crops grown in Virginia. Caused primarily by the fungus Fusarium graminearum (also known as Gibberella zeae), this disease can negatively impact yield and grain quality. Grain may also contain toxins (mycotoxins) produced by the fungus and reduce the price received for grain at local mills and elevators. Corn and small grain residues remaining in the field prior to small grain planting are known to provide a place for the fungus
to overwinter and proliferate during favorable environmental conditions.

Mar 4, 2011 3102-1535
No-Till Seeding of Forage Grasses and Legumes

No-till seeding of forage grasses and legumes can be successful and has become an accepted practice for a number of reasons. One of the primary concerns in establishing new forage stands in a well-tilled seedbed is the threat of soil erosion during the establishment period. Not only is valuable topsoil lost, but resulting ruts and gullies damage equipment and are dangerous to equipment operators. In addition to reducing soil erosion, no-till seedings conserve moisture already present in the seedbed. Moisture conservation, along with a dramatic reduction in water run-off, improves the water supply for the new seedlings. No-till seeding methods also require less time and fuel than traditional methods because rocks remain below the soil surface.

May 1, 2009 418-007
No-Tillage Small Grain Production in Virginia May 1, 2009 424-005
Nozzles: Selection and Sizing

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.

Jan 31, 2014 442-032 (BSE-103P)
On the Cover of “Science” Sep 7, 2011
PPWS News 2011 Sep 7, 2011
Peanut (Arachis hypogaea, L.) Nutrition

Maintaining the right soil pH for each crop ensures optimal nutrient uptake by plants. For peanut, the recommended pH range is 5.8 – 6.2. If soil pH is higher than 6.2, manganese (Mn) or boron (B) deficiency may occur; if pH is less than 5.8, zinc (Zn) toxicity problems could be favored. Therefore, taking soil samples correctly is very important for correcting soil pH. A single composite sample should be taken for each 5 irrigated and 10 rainfed acres. This sample should be composed of 20 or more subsamples collected from an imaginary grid uniformly covering the land area. The subsamples should be well mixed together and only a small composite sample should be retained and sent to the soil lab.

Sep 1, 2014 PPWS-40NP
Peanut Crop Physiology Related Projects at Tidewater Agricultural Research and Extension Center 2010 Dec 16, 2011 PPWS-2
Peanut Variety & Quality Evaluation Results 2016

Due to suitability to the environmental conditions and existence of a strong peanut industry tailored to process primarily the large-seeded Virginia-type peanut, growers in Virginia, North Carolina, and South Carolina generally grow Virginia-type cultivars. In the view of a common interest in the Virginia-type peanut, the three states are working together through a multi-state project, the Peanut Variety Quality Evaluation (PVQE), to evaluate advanced breeding lines and commercial cultivars throughout their production regions.

Dec 20, 2016 AREC-198NP
Peanut Variety and Quality Evaluation results, 2015

Along with agronomic and grade information, data on kernel and pod quality are essential for release of new peanut cultivars to ensure acceptability by the entire peanut trade. The present report contains the quality data collected on 5 Virginia-type cultivars that currently are on the market and 31 advanced breeding lines tested in the Peanut Variety and Quality Evaluation (PVQE) small plots in 2015.

Apr 1, 2016 AREC-172NP
Pest Management Guide: Field Crops, 2017 Feb 17, 2017 456-016 (ENTO-221P)
Pest Management Guide: Home Grounds and Animals, 2017 Feb 15, 2017 456-018 (ENTO-220P)
Pest Management Guide: Horticultural and Forest Crops, 2017 Feb 17, 2017 456-017 (ENTO-222P)
Pest Monitoring Calendar for Home Lawns in Virginia May 1, 2009 430-524
Plant Disease Diagnostic Form May 13, 2016 450-097 (ENTO-198NP)
Plant Injury From Herbicide Residue

In recent years, an increased number of cases of
injury from herbicide residue in straw/hay, manure,
and compost have been diagnosed in the Virginia
Tech Plant Disease Clinic. Growers are surprised and
dismayed to learn that manure, straw, mulch, or other
amendments intended to improve their garden or
landscape might have such unforeseen consequences.
Of particular concern to organic growers are herbicide

Aug 22, 2016 PPWS-77P
Powdery Mildew of Ornamental Plants May 1, 2009 450-603
Prevention and Control of Palmer Amaranth in Soybean Jun 1, 2016 2808-1006 (PPWS-78NP)
Problem-free Shrubs for Virginia Landscapes Jun 27, 2016 450-236 (PPWS-69P)
Problem-free Trees for Virginia Landscapes Oct 19, 2016 450-237 (PPWS-70P)
Pyridine Herbicide Carryover: Causes and Precautions May 9, 2012 VTTP-6NP
Recent Faculty Hires Sep 7, 2011
Reducing Pesticide Use in the Home Lawn and Garden Apr 29, 2015 450-725 (PPWS-56P)
Root-knot Nematode in Field Corn

Order: Tylenchida

Family: Heteroderidae

Species: Meloidogyne incognita (southern root-knot nematode), M. arenaria (peanut root-knot nematode), M. javanica (Javanese root-knot nematode), M. hapla (northern root-knot nematode; not found in corn)

Size: Adult females are up to 1/16 inch in diameter.

Color: Adult females are a translucent cream color.

Description: Adult females are pear shaped and sedentary.

May 1, 2009 444-107
Rose Rosette Disease Sep 17, 2012 450-620 (PPWS-10P)
Second Annual MPS Mini-Symposium Sep 7, 2011
Soybean Disease Control: Response of Soybeans to Foliar Sprays of Fungicides in 2005 May 1, 2009 450-561
Soybean Rust Incidence and the Response of Soybeans to Foliar Fungicides in 2006 May 1, 2009 450-562
Soybean Rust Incidence and the Response of Soybeans to Fungicides in 2007 May 1, 2009 2810-1016
Soybean Rust Incidence and the Response of Soybeans to Fungicides in 2008 Nov 19, 2009 2911-1420
Soybean Rust Incidence and the Response of Soybeans to Fungicides in 2009 Dec 21, 2010 3012-1520
Spring and Summer Lawn Management Considerations for Cool-Season Turfgrasses

There is no time of year that generates as much excitement in the management of lawns and landscapes as spring. Sales of all lawn and garden products soar as many homeowners strive for the best looking lawn possible. However, your enthusiasm for returning the lawn to tip-top shape should be tempered enough so that you make sound agronomic and environmental management decisions. Smart choices now will result in a healthy, dense turf canopy that will better withstand the environmental extremes of the summer months.

May 1, 2009 430-532
Spring and Summer Lawn Management Considerations for Warm-Season Turfgrasses

Soil testing. Sampling the soil to determine pH and nutrient levels is always a prudent choice in developing a management program for a lawn, especially if a soil test has not been done within the past three years (Figure 1). Any time of year is appropriate for sampling. A majority of Virginia soils are acidic and need to be amended with periodic applications of lime. For information on how to properly sample your soil, consult Soil Sampling for the Home Gardener, Virginia Cooperative Extension publication 452-129, at http://pubs.ext.vt.edu/452-129/. For additional soil testing information, see the presentation "Soil Testing for the Lawn and Landscape," at http://breeze.ag.vt.edu/p36588349/.

May 1, 2009 430-533
Successful No-Tillage Corn Production Jul 29, 2009 424-030
Theses and Dissertations Sep 7, 2011
Virginia Boxwood Blight Task Force May 20, 2014 PPWS-30
Virginia Cotton Production Guide 2016

Proper soil fertility management ensures sufficient nutrients for maximum cotton production. Obtaining and maintaining appropriate soil nutrient concentrations is imperative, as fertilizer inputs are the largest component of production budgets for Virginia cotton farmers. At the same time, excessive nutrient application wastes money, wastes natural resources, and can negatively impact yields and environmental quality.

Feb 22, 2016 AREC-124NP (AREC-165NP)
Virginia Cotton Report, 2006: Evaluation of Chemicals and Variety Selection for Control of Nematodes in Cotton May 1, 2009 424-234
Virginia Master Naturalist, Basic Training Course, Botany (Introductory Version) Jan 31, 2014 ANR-12NP
Westwood Lab at International Parasitic Plant Conference Sep 7, 2011