The Plant Diagnostic Center is a service of the LSU AgCenter and is supported by the Department of Plant Pathology and Crop Physiology. Routine plant diagnostic services are provided to extension personnel across Louisiana as well as to state residents at a charge of $20 per sample. The center diagnoses plant samples with problems caused by fungi, bacteria, viruses, nematodes, insect pests and mites, as well as nonpathogenic agents and weed identification
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Mirlitons are susceptible to a common fungal disease called powdery mildew. Mirliton powdery mildew is caused by Podosphaera xanthii.
The Plant Diagnostic Center (PDC) is a service lab of the LSU AgCenter and is supported by the Department of Plant Pathology and Crop Physiology.
Oleander leaf scorch (OLS) is a deadly disease of oleander that was first reported in California in the early 1990s.
Rose rosette disease is caused by a virus known as Rose rosette virus. It is a devastating disease of roses – particularly since all cultivars are susceptible.
Downy mildew of sweet basil is a destructive disease that was first detected in the United States in 2007.
Citrus greening, also known as yellow shoot disease or huanglongbing, is one of the most devastating diseases of citrus worldwide.
Lichens are fascinating plants. They are composed of two different organisms – a fungal partner and a photosynthetic partner living in a symbiotic relationship.
Bacterial gall on Loropetalum (Loropetalum chinense) is caused by a plant pathogenic bacterium called Pseudomonas savastanoi.
Sweet olive is susceptible to a bacterial disease called leaf scorch, which is caused by Xylella fastidiosa.
Boxwood blight, also known as box blight, is a fungal disease caused by Calonectria pseudonaviculata (Cylindrocladium pseudonaviculata, C. buxicola).
Bitter rot of apple is a fungal disease commonly caused by two species known as Colletotrichum gloeosporioides and C. acutatum.
Like Spanish moss, ball moss is an epiphyte and belongs to family Bromeliaceae.
Citrus canker is a bacterial disease caused by Xanthomonas citri subsp. citri. It is thought to have originated in Southeast Asia.
Large patch is the most common disease of warm-season turfgrasses in Louisiana. This disease is caused by the soilborne fungus Rhizoctonia solani.
Take-all root rot is caused by the soilborne fungus Gaeumannomyces graminis var. graminis (Ggg), frequently is found in association with turfgrass roots.
Texas Phoenix palm decline is a fatal disease of palms. Also called date palm lethal decline, it had only been found in Florida and Texas until recently.
In Louisiana, Canary Island date palm (Phoenix canariensis Hort. Ex Chabaud) is a signature palm planted in New Orleans and nearby cities.
This publication is intended to introduce home vegetable gardeners to the various methods used to manage the many diseases that affect these crops. (PDF Format Only)
Centipede grass is a popular lawn grass in Louisiana. This publcation covers factors that contribute to centipede decline: improper plant nutrition, cultural practices, and soil and water conditions. (PDF Format Only)
We often see lawns with mushrooms or doughnut rings of dying or dark green grass. These are referred to as "fairy rings." This publication includes information on how to control fairy rings in your lawn. (PDF Format Only)
Nematode assay form is now available as a fill-in form. It should be included with all samples submitted for nematode analysis.
The LSU AgCenter Plant Diagnostic Center diagnoses plant samples with problems caused by fungi, bacteria, viruses, nematodes, insects pests and mites, as well as nonpathogenic agents. .
Leaf and crown rot is a common problem on liriope (or lily turf) in both nursery and landscape settings. All species and cultivars of liriope are reported to be susceptible to this disease. Proper identification is the key to sucessful disease management. This fact sheet is intended to aid in the identification and management of this disease. (PDF format only)
Proper identification is the key to sucessful disease management. This fact sheet is intended to aid in the identification and management of this disease. (PDF format only)
Tomato yellow leaf curl is a relatively new whitefly-transmitted virus disease of tomatoes in the United States. It was first observed in South Florida in 1997 and has since spread throughout much of the Southeast, including Louisiana where it was first observed in 2000. Proper identification is the key to successful disease management. This fact sheet is intended to aid in the identification and management of this disease of tomatoes. (PDF Format Only)
The southern root-knot nematode (Meloidogyne incognita) is a widespread problem in Louisiana. This pest favors the soils where most vegetables are produced and has been found in about 25 percent of the vegetable gardens in our state. This nematode can be extremely damaging to some crops and causes severe losses. (PDF Format Only)
Solanum melongena L. (eggplant) is a member of Solanaceae family. This is frost-tender herbaceous perennial, usually grown as an annual plant. Diseases such as Verticillium wilt, Southern blight, Phomopsis blight, Anthracnose fruit rot and Altenaria blight are commonly associated with eggplant and can reduce its harvestable yield significantly.
Plant-parasitic nematodes attack every field crop grown in Louisiana, including cotton, soybeans, corn, milo, rice, sugarcane, sweet potatoes and wheat. There are certain times of the year when nematode samples should be collected. The best time usually is during fall or early winter. Sampling time, procedures and handling included. (PDF Format Only)
Centipede grass is a popular lawn grass in Louisiana. Although centipede is a low-maintenance grass, proper management is still important. This publcation covers factors that contribute to centipede decline: improper plant nutrition, cultural practices, and soil and water conditions. (PDF Format Only)
This form is required for all the turfgrass samples submitted to the Disease Clinic. Please take a moment to fill in as much information as possible. Each sample should have a separate disease sample form. Samples submittted without a submission form will not be diagnosed.
This publication includes information on the life cycle, damage and control of slime mold on turfgrass. (PDF Format Only)
How to submit a sample to the lab interactive slideshow
Information about publications related to plant diagnostics, including LSU AgCenter's Plant Pathology Disease Identification and Management Series.
Information about testing, fees, and services provided by the LSU AgCenter Plant Diagnostic Center.
Plant Diagnostic Center Home
Please follow the guidelines on how to collect, pack and submit turfgrass samples to the Plant Disease Diagnostic Clinic. These guidelines are specific for turfgrass samples and should be followed strictly. Samples submitted in other manners will not be diagnosed.
It is the dream of every golf course manager, sod producer, landscape contractor and athletic field manager to have healthy green turfgrass. Several factors can shatter this dream, and an important factor such as disease tops of the list. Every year the turfgrass industry spends thousands of dollars to manage diseases. An effective disease management requires an accurate disease diagnosis.
Plant-parasitic nematodes can damage plants in many ways and are considered to be a serious threat to sweet potato production in Louisiana. This publication describes problematic nematode species and management strategies available for these pests. (PDF format only)
Pumpkin (Cucurbita pepo) is a warm-season vegetable that can be grown throughout much of the United States. Together with winter squash, pumpkins are among the most-resistant of the cucurbits to certain diseases and insect damage. However, diseases such as Phytophthora fruit rot, Microdochium blight, Zucchini yellow mosaic, Fusarium rot and gummy stem blight are several common diseases that can severely affect pumpkin production.
The pepper (Capsicum spp) originated in Mexico and surrounding areas of Central America. It is an excellent source of vitamin A, vitamin C and calcium. An important crop in commercial vegetable production, peppers have disease problems with which growers must be concerned.
Cucumber (Cucumis spp.), like other cucurbits (melons, squash, pumpkins, etc.), are attacked by several pathogens that can result in severe crop losses. Most damage is observed on cucumber leaves and stems. Fruits can also be severely affected, resulting in overall poor quality and yield, especially if disease has already weakened the plant.
Like any other crop, squash is susceptible to a variety of diseases that attack below- and above-ground parts of the plant. Major squash diseases include gummy stem blight/black rot, scab, powdery mildew, nematodes and several viral diseases. Because many of the fungal, bacterial and nematode pathogens survive in soil and/or crop debris, crop rotation with non-cucurbit crops for at least three years is highly recommended.
Personnel in the plant disease clinic and their contact information.
Image gallery of strawberry diseases -- bacterial and fungal pathogens affecting appearance as well as marketability of strawberries.
Image gallery of citrus diseases with focus on citrus canker. For more information on this particular disease and its importance, please visit our website with links to additional sources.
Southern blight (or southern wilt) is a disease of hundreds of plant species, including tomatoes. It is favored by moist conditions and high temperatures. The fungus can survive for years in soil and plant debris.