The disease affect most stone plants including peaches, apricots and plums. The symptoms can generally be found in three major parts of plant: fruits, twigs, and leaves. The symptoms on leaves and twigs are often considered as the least notable. Infected leaves initially show small and green colored lesions on under the leaves. They progress into yellowish brown and eventually appear as dark brown or black spots.

Twig lesions start to form on green young stems. The lesions are about 3 up to 6.5 mm in diameter size. They usually first have reddish brown colors then which will turn into darker colors as they enlarge to an oval shape of 3 x 6mm approximately.

About six weeks after petals are fallen, the first and most notable and serious symptoms appear on fruits. Spots, which generally range from 1 to 2 mm in diameter size, are formed on the end of stem. They gradually change its color into dark green or black and grow about few millimeters in diameter. As they enlarge, yellow circles will form around the velvety dark green spots. The spots have raised appearance on fruits instead of sunken figures which can be found most prevalently in other fungal infections. In some severe cases, fruits may be stunted or opened and exposed to further infection by airborne microorganisms.

Peach scab, also known as peach freckles, is a disease of stone fruits caused by the fungi "Cladosporium carpophilum". The disease is most prevalent in wet and warm areas especially southern part of the U.S. as the fungi require rain and wind for dispersal. The fungus causes scabbing, lesions, and defoliating on twig, fruit, and leaf resulting in downgrade of peach quality or loss of fruits due to rotting in severe cases.

Apple scab is a disease of "Malus" trees, such as apple trees, caused by the ascomycete fungus "Venturia inaequalis". The disease manifests as dull black or grey-brown lesions on the surface of tree leaves, buds or fruits. Lesions may also appear less frequently on the woody tissues of the tree. Fruits and the undersides of leaves are especially susceptible. The disease rarely kills its host, but can significantly reduce fruit yields and fruit quality. Affected fruits are less marketable due to the presence of the black fungal lesions.

Sooty blotch and flyspeck is a descriptive term for a condition of darkly pigmented blemishes and smudges caused by a number of different fungi affecting fruit including apples, pear, persimmon, banana, papaya, and several other cultivated tree and vine crops. The greenish black coating resembling soot or flyspeck-like dots grow into irregular stains and blotches during the summer or growing season. They can grow into each other and may cover the entire fruit surface. Frequently blotches run down in a track resembling tears (German: "Regenfleckenkrankheit"). The blotches can be removed by vigorous rubbing or be scratched off revealing a normal peel. Symptoms can be seen particularly well when apples are light or green colored. Late varieties are more susceptible, because the disease builds over a longer growing period.

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 symptoms of Cherry X disease vary greatly depending on the host. On cherry hosts symptoms can usually first be seen on the fruits, causing them to be smaller in size with a leathery skin. Pale fruit is common at harvest time. It is common for symptoms to first be seen in a single branch. The branch may lose its older leaves, and the leaves tend to be smaller with a bronzed complexion.

The rootstock that the cherry is grafted onto can play a significant role in the disease symptoms seen. Rootstocks of Mahaleb cherry exhibit different symptoms from stocks of Colt, Mazzard, or Stockton Morello. When the scion is grafted onto Mahaleb, symptoms consistent with Phytophthora root rot can be seen. To distinguish between root rot and x-disease the wood under the bark at the graft union should be examined. If it is x-disease the wood at the union will have grooves and pits this causes a browning of the phloem and shows the cells in decline. This rapid decline is caused by the rootstock cells near the graft union dying in large quantities. Foliage begins to turn yellow and the curl upward and inward toward the leaf midrib. Trees infected with Mahaleb rootstock die by late summer or early the following year.

When Cherries are grafted onto Colt, Mazzard, or Stockton Morello rootstocks, there is a different range of symptoms. Affected leaves are smaller than normal and the foliage may be sparse. Dieback of shoot tips is common as the disease progresses. Fruit on branches are smaller, lighter, pointed, low sugar content, poor flavor, and a bitter taste.

Peaches are the next most common economic fruit host of the X-disease. Symptoms can be seen after about two months single branches will begin to show symptoms of their individual leaves. These leaves curl up and inward with irregular yellow to reddish-purple spots. These spots can drop out leaving “shotholes”. Leaves that are affected by the disease will fall prematurely. After 2–3 years the entire tree will show symptoms.

Sooty blotch and flyspeck (SBFS) or apple summer disease is a plant disease caused by a complex of saprophytic fungi which colonize the epicuticular wax layer of apple ("Malus" x "domestica" Borkh.). It is found worldwide in regions with moist growing seasons.

Cherry X disease also known as Cherry Buckskin disease is caused by a plant pathogenic phytoplasma. Phytoplasma's are obligate parasites of plants and insects. They are specialized bacteria, characterized by their lack of a cell wall, often transmitted through insects, and are responsible for large losses in crops, fruit trees, and ornamentals. The phytoplasma causing Cherry X disease has a fairly limited host range mostly of stone fruit trees. Hosts of the pathogen include sweet/sour cherries, choke cherry, peaches, nectarines, almonds, clover, and dandelion. Most commonly the pathogen is introduced into economical fruit orchards from wild choke cherry and herbaceous weed hosts. The pathogen is vectored by mountain and cherry leafhoppers. The mountain leafhopper vectors the pathogen from wild hosts to cherry orchards but does not feed on the other hosts. The cherry leafhopper which feeds on the infected cherry trees then becomes the next vector that transmits from cherry orchards to peach, nectarine, and other economic crops. Control of Cherry X disease is limited to controlling the spread, vectors, and weed hosts of the pathogen. Once the pathogen has infected a tree it is fatal and removal is necessary to stop it from becoming a reservoir for vectors.

There are two different manifestations of rainscald: the winter form, which is more severe due to the longer coat of the horse, and the summer form, which is less severe. Horses are usually affected on the back, head, and neck, where insects commonly bite, and the legs, which are commonly infected if the horse is kept in moist footing. Initially, the horse will display a matted coat and bumps which will then progress to crusty scabs and lesions. The animal may also be itchy and display signs of discomfort.

The symptoms of little cherry disease in sweet and sour cherries varies greatly depending on cultivar, with respect to both the range and the severity of symptoms; some cultivars show signs of tolerance.

In infected trees of the commercially important cultivar Lambert, the fruit develops normally until about ten days before harvest, when maturation stops. At picking time, the cherries are 1/2–2/3 of the regular size, dull in color, with an angular pointed shape. The sugar and acid levels of the cherries are severely impacted, resulting in tasteless fruits, lacking both sweetness and flavor. Other cultivars show symptoms similar to those in Lambert, but usually less severe and more varied. Typically, dark-fruited cultivars show more severe fruit symptoms than cultivars with red or yellow fruit. The ability to recover is also dependent on cultivar, with some able to return to fruit sizes and coloring comparable to uninfected trees. The taste, however, never recovers.

Some sweet cherry cultivars display foliage symptoms, with the fruit crop less hidden by the canopy, and leaf symptoms, varying from a slight marginal up-curl of the leaves to marked reddening of leaf surfaces. The general vigor of infected trees may be impaired, though this is not always apparent. Diagnosis of the disease can be assisted by RT-PCR assays.

Other "Prunus" species may act as symptomless or tolerant carriers of the disease; especially cultivars of Japanese flowering cherry ("Prunus serrulata") have been implicated as such.

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".

Rainscald (also known as "dermatophilosis", "rain rot" and "streptothricosis") is a common skin disease in horses that is caused by the bacterium "Dermatophilus congolensis". This is the same organism that causes Mud fever in horses. This disease is very common in cows, sheep and goats and is also found occasionally in cats, dogs, and humans. D. congolensis is a gram-positive bacterium that is thought to originate from the soil. It commonly causes disease in moist tropical areas, but can also be found in wet northern environments. Moisture and high temperatures facilitate the dispersal and penetration of zoospores into the skin, contributing to the spread of the disease.

Ticks, biting flies, and contact with other infected animals also causes the spread of rainscald. Once in the skin, the bacteria cause inflammation of the skin as well as the typical symptoms associated with rainscald.

The hosts for Leucostoma canker include stone fruits such as cultivated peach, plum, prune, cherry ("Prunus spp".), or other wild "Prunus" spp. It can also be found on apple ("Malus domestica"). Stone fruits are referred to as drupe, which are fruits containing a seed encased by a hard endocarp, surrounded by a fleshy outer portion.

Leucostoma canker symptoms differ depending on where on the tree infection takes place. Discoloration occurs in sunken patches on infected twigs. Light and dark concentric circles of narcotic tissue characterize this symptom, occurring near buds killed by cold or on leaf scars. Infections on the nodes are seen 2–4 weeks after bud break. As time passes, darkening occurs within diseased tissues, and eventually, amber gum ooze may seep from infected tissue. Nodal infections are particularly vulnerable in one-year-old shoots that develop within the center of the tree. If fungal growth persists without treatment, scaffold limbs and large branches will likely become invaded within a short time frame. Cankers occurring on branches that are the product of such infections will contain dead twigs or twig stubs at the canker’s center.

The most striking symptom of infection includes cankers located on the main trunk, branch crotches, scaffold limbs, and older branches. A symptom called “flagging” can be found on necrotic scaffold limbs. The cankers are parallel to the long axis of the stem and take on an oval shape. Normally, large-scale production of amber colored gum marks the first external symptom of such cankers. While gum production is the typical plant response to irritation, the gum secretion of Leucostoma occurs in bulk amounts. This gum darkens as time passes, gradually leading to the drying and cracking of bark; thus exposing the blackened tissue below.

As the tree continues to mature in the early growing season, the tree resists additional fungal penetration through the formation of callus rings surrounding the canker. However, the Leucostoma generally reinvades the tissue late in the growing season while the tree switches into dormancy. Due to the alteration of callus production and canker formation, cankers with circular callus rings are usually observed.

Foliar symptoms might develop from branch or twig infections. Symptoms include chlorosis, wilting, and necrosis. Signs include small black structures on dead bark which contain pycnidia.

Little cherry disease or LChD, sometimes referred to as little cherry, K & S little cherry or sour cherry decline, is a viral infectious disease that affects cherry trees, most notably sweet cherries ("Prunus avium") and sour cherries ("Prunus cerasus").

Little cherry disease should not be confused with cherry buckskin disease, which is caused by Phytoplasma.

Note that both diseases are among the diseases referred to as cherry decline.

Infections on the body may give rise to typical enlarging raised red rings of ringworm. Infection on the skin of the feet may cause athlete's foot and in the groin, jock itch. Involvement of the nails is termed onychomycosis, and they may thicken, discolour, and finally crumble and fall off. They are common in most adult people, with up to 20% of the population having one of these infections at any given moment.

Animals such as dogs and cats can also be affected by ringworm, and the disease can be transmitted between animals and humans, making it a zoonotic disease.

Specific signs can be:

- red, scaly, itchy or raised patches

- patches may be redder on outside edges or resemble a ring

- patches that begin to ooze or develop blister

- bald patches may develop, when the scalp is affected

- nails may thicken, discolour or begin to crack

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.

The most common term for the infection, "ringworm", is a misnomer, since the condition is caused by fungi of several different species and not by parasitic worms.

Physiological plant disorders are caused by non-pathological conditions such as poor light, adverse weather, water-logging, phytotoxic compounds or a lack of nutrients, and affect the functioning of the plant system. Physiological disorders are distinguished from plant diseases caused by pathogens, such as a virus or fungus. While the symptoms of physiological disorders may appear disease-like, they can usually be prevented by altering environmental conditions. However, once a plant shows symptoms of a physiological disorder it is likely that that season’s growth or yield will be reduced.

"Verticillium" spp. attack a very large host range including more than 350 species of vegetables, fruit trees, flowers, field crops, and shade or forest trees. Most vegetable species have some susceptibility, so it has a very wide host range. A list of known hosts is at the bottom of this page.

The symptoms are similar to most wilts with a few specifics to "Verticillium". Wilt itself is the most common symptom, with wilting of the stem and leaves occurring due to the blockage of the xylem vascular tissues and therefore reduced water and nutrient flow. In small plants and seedlings, "Verticillium" can quickly kill the plant while in larger, more developed plants the severity can vary. Some times only one side of the plant will appear infected because once in the vascular tissues, the disease migrates mostly upward and not as much radially in the stem. Other symptoms include stunting, chlorosis or yellowing of the leaves, necrosis or tissue death, and defoliation. Internal vascular tissue discoloration might be visible when the stem is cut.

In "Verticillium", the symptoms and effects will often only be on the lower or outer parts of plants or will be localized to only a few branches of a tree. In older plants, the infection can cause death, but often, especially with trees, the plant will be able to recover, or at least continue living with the infection. The severity of the infection plays a large role in how severe the symptoms are and how quickly they develop.

The uncomplicated appearance is that of a number of yellowish, circular, cup-shaped crusts (scutula) grouped in patches like a piece of honeycomb, each about the size of a split pea, with a hair projecting in the center. These increase in size and become crusted over, so that the characteristic lesion can only be seen round the edge of the scab. A mousy odour is often present. Growth continues to take place for several months, when scab and scutulum come away, leaving a shining bare patch destitute of hair. The disease is essentially chronic, lasting from ten to twenty years. It is caused by the growth of a fungus, and pathologically is the reaction of the tissues to the growth.

The fungus was named after a microscopic structure termed "achorion" (a term not used in modern science), seen in scrapings of infected skin, which consists of slender, mycelial threads matted together, bearing oval, nucleated fungal substrate-arthroconidia either free or jointed. This structure is currently called "scutula." The fungus itself is now called "Trichophyton schoenleinii".

During initial infection, the fungal spores would appear to enter through the unbroken cutaneous surface, and to germinate mostly in and around the hair follicle and sometimes in the shaft of the hair.

Burrknot is a tree disorder, which is caused by formation of adventitious root primordia. Although previously classified as disease, is now classified as a disorder, as it is no longer believed to be pathogenic.

An eschar (; Greek: "eschara") is a slough or piece of dead tissue that is cast off from the surface of the skin, particularly after a burn injury, but also seen in gangrene, ulcer, fungal infections, necrotizing spider bite wounds, spotted fevers and exposure to cutaneous anthrax. The term "eschar" is not interchangeable with "scab". An eschar contains necrotic tissue, whereas a scab is composed of dried blood and exudate.

Black eschars are most commonly attributed to anthrax, which may be contracted through herd animal exposure, but can also be obtained from "Pasteurella multocida" exposure in cats and rabbits. A newly identified human rickettsial infection, "R. parkeri" rickettsiosis, can be differentiated from Rocky Mountain spotted fever by the presence of an eschar at the site of inoculation.

Eschar is sometimes called a "black wound" because the wound is covered with thick, dry, black necrotic tissue.

Eschar may be allowed to slough off naturally, or it may require surgical removal (debridement) to prevent infection, especially in immunocompromised patients (e.g. if a skin graft is to be conducted).

If eschar is on a limb, it is important to assess peripheral pulses of the affected limb to make sure blood and lymphatic circulation is not compromised. If circulation is compromised, an escharotomy, or surgical incision through the eschar, may be indicated.

Favid (of "favus" Latin for "honeycomb" or tinea favosa) is a disease usually affecting the scalp, but occurring occasionally on any part of the skin, and even at times on mucous membranes.

The word “Favid” is more used than French word “favus”, which is close to the Latin etymology.

The occurrence of Burrknot is quite common among rootstock, often found on apple tree M ( Malling ) and MM ( Malling-Merton ) rootstocks. At onset it begins to look like a smooth orange bulge growing from the stem or a branch, later, during one to three years, multiple adventitious roots begin to form.

When located on the roots, it is considered to be not very dangerous, but it makes it easier for diseases to infect the tree, and leaves it more susceptible to insects. When many burrknots are present on various location in the tree, it can make the tree unproductive.

Interdigital dermatitis appears as an infections of the skin between the claws and is usually very mild. There may be fluid or a scab in that area, and there is rarely lameness. There is then progression to the heels which become raw and cattle will experience pain. Chronic cases will show changes of the hoof including hyperplasia of the interdigital tissues and muscle atrophy in the affected limb. The horn may become underrun.

Diagnosis is principally based on history and clinical signs. It is very rare that attempts are made to isolate the bacteria.