Panama disease is a plant disease of the roots of banana plants. It is a type of Fusarium wilt, caused by the fungal pathogen "Fusarium oxysporum f. sp. cubense" (Foc). The pathogen is resistant to fungicide and cannot be controlled chemically.

During the 1950s, Panama disease wiped out most commercial Gros Michel banana production. The Gros Michel banana was the dominant cultivar of bananas, and the blight inflicted enormous costs and forced producers to switch to other, disease-resistant cultivars. New strains of Panama disease currently threaten the production of today's most popular cultivar, Cavendish.

Grey leaf spot (GLS) is a foliar fungal disease that affects maize, also known as corn. There are two fungal pathogens that cause GLS, which are "Cercospora zeae-maydis" and "Cercospora zeina" . Symptoms seen on corn include leaf lesions, discoloration (chlorosis), and foliar blight. The fungus survives in debris of topsoil and infects healthy crop via asexual spores called conidia. Environmental conditions that best suit infection and growth include moist, humid, and warm climates. Poor airflow, low sunlight, overcrowding, improper soil nutrient and irrigation management, and poor soil drainage can all contribute to the propagation of the disease. Management techniques include crop resistance, crop rotation, residue management, use of fungicides, and weed control. The purpose of disease management is to prevent the amount of secondary disease cycles as well as to protect leaf area from damage prior to grain formation. Corn grey leaf spot is an important disease of corn production in the United States, economically significant throughout the Midwest and Mid-Atlantic regions. However, it is also prevalent in Africa, Central America, China, Europe, India, Mexico, the Philippines, northern South America, and Southeast Asia. The teleomorph (sexual phase) of "Cercospora Zeae-Maydis" is assumed to be "Mycosphaerella sp."

Cladosporium fulvum is an Ascomycete called "Passalora fulva", a non-obligate pathogen that causes the disease on tomato known as the Tomato leaf mold. P. fulva only attacks tomato plants, especially the foliage, and it is a common disease in the greenhouses, but can also occur in the field. The pathogen is likely to grow in humid and cool conditions. In the greenhouses, this disease causes big problems during the fall, in the early winter and spring, due to the high relative humidity of air and the temperature, that are propitious for the leaf mold development. This disease was first described in the North Carolina, by Mordecai Cubitt Cooke (1883), on cultivated tomato (Cooke 1883), although it is original from South and Central America. The causal fungus of tomato leaf mold may also be referred as Cladosporium fulvum (Cooke 1883), a former name.

Control of Leucostoma Canker is possible through a combination of pest and crop management techniques following life cycles of the trees. The strategy is implemented following techniques aimed at reducing number of pathogenic inoculum, minimizing dead or injured tissues to prevent infection, and improving tree health to improve rapid wound healing. Chemical controls have not been very effective at controlling this disease with no fungicides registered specifically for control of "Leucostoma" spp., and demethylation-inhibiting (DMI) fungicides having almost no effect on "L. persoonii".

Fusarium wilt is a common vascular wilt fungal disease, exhibiting symptoms similar to Verticillium wilt. The pathogen that causes Fusarium wilt is "Fusarium oxysporum" ("F. oxysporum"). The species is further divided into forma specialis based on host plant.

Ascochyta blights occur throughout the world and can be of significant economic importance. Three fungi contribute to the ascochyta blight disease complex of pea ("Pisum sativum"). "Ascochyta pinodes" (sexual stage: "Mycosphaerella pinodes") causes Mycosphaerella blight. "Ascochyta pinodella" (synonym: "Phoma medicaginis" var. "pinodella") causes Ascochyta foot rot, and "Ascochyta pisi" causes Ascochyta blight and pod spot. Of the three fungi, "Ascochyta pinodes" is of the most importance. These diseases are conducive under wet and humid conditions and can cause a yield loss of up to fifty percent if left uncontrolled. The best method to control ascochyta blights of pea is to reduce the amount of primary inoculum through sanitation, crop-rotation, and altering the sowing date. Other methods—chemical control, biological control, and development of resistant varieties—may also be used to effectively control ascochyta diseases.

Leucostoma canker is a fungal disease that can kill stone fruit ("Prunus" spp.). The disease is caused by the plant pathogens "Leucostoma persoonii" and "Leucostoma cinctum" (teleomorph) and "Cytospora leucostoma" and "Cytospora cincta" (anamorphs). The disease can have a variety of signs and symptoms depending on the part of the tree infected. One of the most lethal symptoms of the disease are the Leucostoma cankers. The severity of the Leucostoma cankers is dependent on the part of the plant infected. The fungus infects through injured, dying or dead tissues of the trees. Disease management can consist of cultural management practices such as pruning, late season fertilizers or chemical management through measures such as insect control. Leucostoma canker of stone fruit can cause significant economic losses due to reduced fruit production or disease management practices. It is one of the most important diseases of stone fruit tree all over the world.

The first strategy of management is the cultural practices for reducing the disease. It includes adequating row and plant spacing that promote better air circulation through the canopy reducing the humidity; preventing excessive nitrogen on fertilization since nitrogen out of balance enhances foliage disease development; keeping the relatively humidity below 85% (suitable on greenhouse), promote air circulation inside the greenhouse, early planting might to reduce the disease severity and seed treatment with hot water (25 minutes at 122 °F or 50 °C).

Growth of the bacteria is possible between 32–90 °F, with the most ideal conditions between 70–80 °F. Post-harvest storage and transportation is difficult for tropical and other warm environments when the air is not properly ventilated during these processes. Higher temperatures and high humidity are ideal growing conditions for the bacteria making ventilation a big priority when trying to combat this disease.

"F. oxysporum" is a major wilt pathogen of many economically important crop plants. It is a soil-borne pathogen, which can live in the soil for long periods of time, so rotational cropping is not a useful control method. It can also spread through infected dead plant material, so cleaning up at the end of the season is important.

One control method is to improve soil conditions because "F. oxysporum" spreads faster through soils that have high moisture and bad drainage. Other control methods include planting resistant varieties, removing infected plant tissue to prevent overwintering of the disease, using soil and systemic fungicides to eradicate the disease from the soil, flood fallowing, and using clean seeds each year. Applying fungicides depends on the field environment. It is difficult to find a biological control method because research in a greenhouse can have different effects than testing in the field. The best control method found for "F. oxysporum" is planting resistant varieties, although not all have been bred for every forma specialis.

"F. oxysporum" f. sp. "batatas" can be controlled by using clean seed, cleaning up infected leaf and plant material and breeding for resistance. Fungicides can also be used, but are not as effective as the other two because of field conditions during application. Fungicides can be used effectively by dip treating propagation material.

Different races of "F. oxysporum" f. sp. "cubense", Panama disease on banana, can be susceptible, resistant and partially resistant. It can be controlled by breeding for resistance and through eradication and quarantine of the pathogen by improving soil conditions and using clean plant material. Biological control can work using antagonists. Systemic and soil fungicides can also be used.

The main control method for "F. oxysporum" f. sp. "lycopersici", vascular wilt on tomato, is resistance. Other effective control methods are fumigating the infected soil and raising the soil pH to 6.5-7.

The most effective way to control "F. oxysporum" f. sp. "melonis" is to graft a susceptible variety of melon to a resistant root-stock. Resistant cultivars, liming the soil to change soil pH to 6-7, and reducing soil nitrogen levels also help control "F. oxysporum" f. sp. "melonis".

The fungus "Trichoderma viride" is a proven biocontrol agent to control this disease in an environment friendly way.

Two external symptoms help characterize Panama disease of banana:

- Yellow leaf syndrome, the yellowing of the border of the leaves which eventually leads to bending of the petiole.

- Green leaf syndrome, which occurs in certain cultivars, marked by the persistence of the green color of the leaves followed by the bending of the petiole as in yellow leaf syndrome. Internally, the disease is characterized by vascular discoloration. This begins in the roots and rhizomes with a yellowing that proceeds to a red or brown color in the pseudostem.

These symptoms often get confused with the symptoms of bacterial wilt of banana, but there are ways to differentiate between the two diseases:

- Fusarium wilt proceeds from older to younger leaves, but bacterial wilt is the opposite.

- Fusarium wilt has no symptoms on the growing buds or suckers, no exudates visible within the plant, and no symptoms in the fruit. Bacterial wilt can be characterized by distorted or necrotic buds, bacterial ooze within the plant, and fruit rot and necrosis.

Once a banana plant is infected, it will continue to grow and any new leaves will be pale in color. Recovery is rare, but if it does occur any new emerging suckers will already be infected and can propagate disease if planted.

"Fusarium oxysporum f. sp. cubense" (Foc) is most prominent in banana and plantain, but some other similar relatives are also susceptible to infection. Different races of the disease are used to classify different major hosts affected by Foc. Race 1 was the initial outbreak which destroyed much of the world's Gros Michel bananas. Cavendish bananas are resistant to race 1, but tropical race 4 (or subtropical race 4) is the classification for Foc which affects Cavendish. Race 2 affects a cooking and dessert banana, Bluggoe.

Snow mold is a type of fungus and a turf disease that damages or kills grass after snow melts, typically in late winter. Its damage is usually concentrated in circles three to twelve inches in diameter, although yards may have many of these circles, sometimes to the point at which it becomes hard to differentiate between different circles. Snow mold comes in two varieties: pink or gray. While it can affect all types of grasses, Kentucky bluegrass and fescue lawns are least affected by snow mold.

Velvet Blight is a disease that affects the stems, branches, leaves, fruits or trunks of plants and trees. This disease is primarily caused by three fungal species from the genus "Septobasidium": "S. bogoriense", "S. pilosum" and "S. theae".

It is known to affect mainly tea plants ("Thea" genus).

The most studied of these species is "S. bogoriense", most notably due to the work of Ernst Albert Gäumann. "S. bogoriense" is named after the Herbarium Bogoriense (Bogor, West Java, Indonesia) which is the place where it was first identified on the bark of an unspecified tree and named by E. Nyman on June 3, 1898. This species was also listed in Otto Warburg's Monsunia in 1900.

Shot hole disease (also called Coryneum blight) is a serious fungal disease that creates BB-sized holes in leaves, rough areas on fruit, and concentric lesions on branches. The pathogen that causes shot hole disease is "Wilsonomyces carpophilus".

Beet vascular necrosis and rot is a soft rot disease caused by the bacterium Pectobacterium carotovorum" subsp. "betavasculorum, which has also been known as "Pectobacterium betavasculorum" and "Erwinia carotovora" subsp. "betavasculorum". It was classified in the genus "Erwinia" until genetic evidence suggested that it belongs to its own group; however, the name Erwinia is still in use. As such, the disease is sometimes called Erwinia rot today. It is a very destructive disease that has been reported across the United States as well as in Egypt. Symptoms include wilting and black streaks on the leaves and petioles. It is usually not fatal to the plant, but in severe cases the beets will become hollowed and unmarketable. The bacteria is a generalist species which rots beets and other plants by secreting digestive enzymes that break down the cell wall and parenchyma tissues. The bacteria thrive in warm and wet conditions, but cannot survive long in fallow soil. However, it is able to persist for long periods of time in the rhizosphere of weeds and non-host crops. While it is difficult to eradicate, there are cultural practices that can be used to control the spread of the disease, such as avoiding injury to the plants and reducing or eliminating application of nitrogen fertilizer.

Blight refers to a specific symptom affecting plants in response to infection by a pathogenic organism. It is a rapid and complete chlorosis, browning, then death of plant tissues such as leaves, branches, twigs, or floral organs. Accordingly, many diseases that primarily exhibit this symptom are called blights. Several notable examples are:

- Late blight of potato, caused by the water mold "Phytophthora infestans" (Mont.) de Bary, the disease which led to the Great Irish Famine

- Southern corn leaf blight, caused by the fungus "Cochliobolus heterostrophus" (Drechs.) Drechs, anamorph "Bipolaris maydis" (Nisikado & Miyake) Shoemaker, incited a severe loss of corn in the United States in 1970.

- Chestnut blight, caused by the fungus "Cryphonectria parasitica" (Murrill) Barr, has nearly completely eradicated mature American chestnuts in North America.

- Fire blight of pome fruits, caused by the bacterium "Erwinia amylovora" (Burrill) Winslow "et al.", is the most severe disease of pear and also is found in apple and raspberry, among others.

- Bacterial leaf blight of rice, caused by the bacterium "Xanthomonas oryzae" (Uyeda & Ishiyama) Dowson.

- Early blight of potato and tomato, caused by species of the ubiquitous fungal genus "Alternaria"

- Leaf blight of the grasses

On leaf tissue, symptoms of blight are the initial appearance of lesions which rapidly engulf surrounding tissue. However, leaf spot may, in advanced stages, expand to kill entire areas of leaf tissue and thus exhibit blight symptoms.

Blights are often named after their causative agent, for example Colletotrichum blight is named after the fungi "Colletotrichum capsici", and Phytophthora blight is named after the water mold "Phytophthora parasitica".

Bacterial soft rots are caused by several types of bacteria, but most commonly by species of gram-negative bacteria, "Erwinia", "Pectobacterium", and "Pseudomonas". It is a destructive disease of fruits, vegetables, and ornamentals found worldwide, and effects genera from nearly all the plant families. The bacteria mainly attack the fleshy storage organs of their hosts (tubers, corms, bulbs, and rhizomes), but they also affect succulent buds, stems, and petiole tissues. With the aid of special enzymes, the plant is turned into a liquidy mush in order for the bacteria to consume the plant cell's nutrients. Disease spread can be caused by simple physical interaction between infected and healthy tissues during storage or transit. The disease can also be spread by insects. Control of the disease is not always very effective, but sanitary practices in production, storing, and processing are something that can be done in order to slow the spread of the disease and protect yields.

The amount of initial inoculum will be reduced when a crop other than corn is planted for ≥2 years in that given area; meanwhile proper tillage methods are carried out. Clean plowing and 1-year crop rotation in the absence of corn allows for greater reductions of the disease as well. Note that conventional tilling can reduce disease but can lead to greater soil erosion.

Gray snow mold ("Typhula" spp. or Typhula blight) is the less damaging form of snow mold. While its damage may appear widespread, it typically does little damage to the grass itself, only to the blades. Unlike most plant pathogens, it is able to survive throughout hot summer months as sclerotia under the ground or in plant debris. Typhula blight is commonly found in United States in the Great Lakes region and anywhere with cold winter temperatures and persistent snow fall.

"W. carpophilus" can remain viable for several months and spores are often airborne. Since the fungi thrive in wet conditions, overhead watering should be avoided. Remove and dispose of any infected buds, leaves, fruit and twigs. In fall, fixed copper or Bordeaux mixture can be applied.

This disease is mainly found in tropical climates in Southern Asia, however some scattering exists:

The bacteria can survive in the rhizosphere of other crops such as tomato, carrots, sweet potato, radish, and squash as well as weed plants like lupin and pigweed, so it is very hard to get rid of it completely. When it is known that the bacterium is present in the soil, planting resistant varieties can be the best defense against the disease. Many available beet cultivars are resistant to "Pectobacterium carotovorum" subsp. "betavasculorum", and some examples are provided in the corresponding table. A comprehensive list is maintained by the USDA on the Germplasm Resources Information Network.

Even though some genes associated with root defense response have been identified, the specific mechanism of resistance is unknown, and it is currently being researched.

Certain techniques can be used to determine which pathogen is causing disease. One standard technique for distinguishing strains is microscopy. Under a microscope, "M. pinodes" can be diagnosed by the presence of pseudothecia. "P pinodella" can be diagnosed by the size of conidia produced. "P. pinodella" produces conidia that are smaller than the conidia of "M. pinodes" or "A. pisi". "A. pisi" can be diagnosed by the color of the conidia. In comparison to the light colored, buff spore masses of "M. pinodes" and "P. pinodella" produced on oatmeal agar, "A. pisi" spores masses are carrot red.

Other techniques for diagnosis involve serological assays, isoenzyme analysis, restriction fragment length polymorphisms (RFLPs), random amplified polymorphic DNA (RAPD) assays, and by using monoclonal antibodies.

Verticillium wilt is a wilt disease of over 350 species of eudicot plants caused by six species of Verticillium genus, "V. dahliae", "V. albo-atrum", "V. longisporum", V. nubilum, V. theobromae and

V. tricorpus. (See, for example, Barbara, D.J. & Clewes, E. (2003). "Plant pathogenic Verticillium species: how many of them are there?" Molecular Plant Pathology 4(4).297-305. Blackwell Publishing.) Many economically important plants are susceptible including cotton, tomatoes, potatoes, oilseed rape, eggplants, peppers and ornamentals, as well as others in natural vegetation communities. Many eudicot species and cultivars are resistant to the disease and all monocots, gymnosperms and ferns are immune.

Symptoms are superficially similar to "Fusarium" wilts. There is no chemical control for the disease but crop rotation, the use of resistant varieties and deep plowing may be useful in reducing the spread and impact of the disease.

"Verticillium" wilt begins as a mild, local infection, which over a few years will grow in strength as more virile strains of the fungus develop. If left unchecked the disease will become so widespread that the crop will need to be replaced with resistant varieties, or a new crop will need to be planted altogether.

Control of "Verticilium" can be achieved by planting disease free plants in uncontaminated soil, planting resistant varieties, and refraining from planting susceptible crops in areas that have been used repeatedly for solanaceous crops. Soil fumigation can also be used, but is generally too expensive over large areas.

In tomato plants, the presence of ethylene during the initial stages of infection inhibits disease development, while in later stages of disease development the same hormone will cause greater wilt. Tomato plants are available that have been engineered with resistant genes that will tolerate the fungus while showing significantly lower signs of wilting.

"Verticillium albo-altrum", "Verticilium dahliae" and "V. longisporum" can overwinter as melanized mycelium or microsclerotia within live vegetation or plant debris. As a result, it can be important to clear plant debris to lower the spread of disease. "Verticilium dahliae" and "V. longisporum" are able to survive as microsclerotia in soil for up to 15 years.

Susceptible tomato seedlings inoculated with arbuscular mycorrhizal fungi and "Trichoderma Harzianum" show increased resistance towards "Verticillium" wilt.