| Monilinia laxa | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Leotiomycetes |
| Order: | Helotiales |
| Family: | Sclerotiniaceae |
| Genus: | Monilinia |
| Species: | M. laxa |
| Binomial name | |
| Monilinia laxa (Aderh. & Ruhland) Honey (1945) | |
| Synonyms | |
Monilia cinerea Contents | |
Monilinia laxa is a plant pathogen that is the causal agent of brown rot of stone fruits. [1]
Monilinia laxa is an ascomycete fungus that is responsible for the brown rot blossom blight disease that infects many different types of stone fruit trees, such as apricots, cherries and peaches. [2] It can also occasionally affect some pome fruits; for example, apples and pears. [3] The pathogen overwinters on infected plant parts, particularly on infected twigs, branches, old flower parts or mummified fruits. In spring, the pathogen produces asexual conidia on the aforementioned infected plant debris. In addition, apothecia, which are small, open cup, mushroom-like sexual propagative structures of M. laxa that produce ascospores, also develop on the fallen fruits on the ground. [4] Both asexual (conidia) and sexual (ascospores) spore types are spread during the spring [4] via wind and rain in which they infect blossoms and young shoots. [5] Floral tissue is the most susceptible to both spores’ infection when the trees are in full bloom. The infected floral tissues are responsible for the production of the secondary inoculums that further continues the disease cycle during the spring season. If the environmental conditions are very conducive (i.e. warm and wet environments), infection can also occur in non-flowering shoots or leaves. Infection is sometimes not visible until after the fruit begins to ripen and the pit hardens. These ripe fruits are at a high risk of being infected and passing the disease onto other plants during harvest. [4]
Throughout the entire world, brown rot is arguably the most common reason for crop loss of stone fruits both before and after harvest, especially in regions with warmer temperatures and wet climates.[5] This disease has actually been shown to have a variety of incidence from year to year due to environmental variation. Before the discovery of extremely effective fungicides, when fruit ripened during a period of high rainfall, there were significant losses due to Brown rot blossom blight.[5] After centuries of studying this disease in both Europe and North America, the use of fungicides have more recently become effective. Demethylation inhibitor (DMI) fungicides and Benzimidazole (BZI) fungicides are both examples of common fungicides that have been used to treat brown rot. However, since the beginning of these fungicides, another set of problems arose. After time, brown rot has become resistant to a few fungicides including both DMI and BZI. Luckily, scientists have been able to develop strategies for managing or delaying fungicide resistance to Brown rot blossom blight.[6]
In addition to this, brown rot has been shown to be of serious economic importance even though it has been harder to estimate. Brown rot can cause detrimental losses to stone fruits in very wet seasons during flowering or immediately pre-harvest. Brown rot mostly occurs on maturing fruit close to harvest. Moreover, these losses may occur to fruit after postharvest. For example, post harvest decay of fruits have been approximated to be about 9% loss during transporting and marketing just in the US. [6]
 | The examples and perspective in this section deal primarily with the United States and do not represent a worldwide view of the subject.(November 2022) |
Monilinia laxa proliferates the most in warm and wet weather. [3] Therefore, it is unsurprising to find that it is most commonly found in California as well as the midwestern and northeastern states. Conversely, the disease has not been found in the southeastern states. Outside of the United States, M. laxa is commonly found in Europe, South Africa, and Chile. [3]
Conidia begin to develop on infected plant debris once the temperature reaches 40 °F (4 °C). While infection does not occur below 50 °F (10 °C), it does occur once the temperature increases beyond that point. [4] The ideal temperature for M. laxa infection is between 59–77 °F (15–25 °C). [7] The spores produced by this pathogen can be dispersed by both wind and rain. However, the fungus is also able to proliferate in dry and highly humid conditions. Compared to in cooler conditions, at high humidity ash-gray-brown spore masses [3] can form on the diseased flowers and twig cankers. [8] Typically fruit susceptibility to brown rot increases about two to three weeks prior to harvest. [3]
Botrytis cinerea is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as "botrytis bunch rot"; in horticulture, it is usually called "grey mould" or "gray mold".
Uncinula necator is a fungus that causes powdery mildew of grape. It is a common pathogen of Vitis species, including the wine grape, Vitis vinifera. The fungus is believed to have originated in North America. European varieties of Vitis vinifera are more or less susceptible to this fungus. Uncinula necator infects all green tissue on the grapevine, including leaves and young berries. It can cause crop loss and poor wine quality if untreated. The sexual stage of this pathogen requires free moisture to release ascospores from its cleistothecia in the spring. However, free moisture is not needed for secondary spread via conidia; high atmospheric humidity is sufficient. Its anamorph is called Oidium tuckeri.
Grape black rot is a fungal disease caused by an ascomycetous fungus, Guignardia bidwellii, that attacks grape vines during hot and humid weather. “Grape black rot originated in eastern North America, but now occurs in portions of Europe, South America, and Asia. It can cause complete crop loss in warm, humid climates, but is virtually unknown in regions with arid summers.” The name comes from the black fringe that borders growing brown patches on the leaves. The disease also attacks other parts of the plant, “all green parts of the vine: the shoots, leaf and fruit stems, tendrils, and fruit. The most damaging effect is to the fruit”.
Monilinia fructicola is a species of fungus in the order Helotiales. A plant pathogen, it is the causal agent of brown rot of stone fruits.
Podosphaera leucotricha is a plant pathogen that can cause powdery mildew of apples and pears.
Alternaria solani is a fungal pathogen that produces a disease in tomato and potato plants called early blight. The pathogen produces distinctive "bullseye" patterned leaf spots and can also cause stem lesions and fruit rot on tomato and tuber blight on potato. Despite the name "early," foliar symptoms usually occur on older leaves. If uncontrolled, early blight can cause significant yield reductions. Primary methods of controlling this disease include preventing long periods of wetness on leaf surfaces and applying fungicides. Early blight can also be caused by Alternaria tomatophila, which is more virulent on stems and leaves of tomato plants than Alternaria solani.
Didymella bryoniae, syn. Mycosphaerella melonis, is an ascomycete fungal plant pathogen that causes gummy stem blight on the family Cucurbitaceae, which includes cantaloupe, cucumber, muskmelon and watermelon plants. The anamorph/asexual stage for this fungus is called Phoma cucurbitacearum. When this pathogen infects the fruit of cucurbits it is called black rot.
Glomerella cingulata is a fungal plant pathogen, being the name of the sexual stage (teleomorph) while the more commonly referred to asexual stage (anamorph) is called Colletotrichum gloeosporioides. For most of this article the pathogen will be referred to as C. gloeosporioides. This pathogen is a significant problem worldwide, causing anthracnose and fruit rotting diseases on hundreds of economically important hosts.
Monilinia fructigena is a plant pathogen in the fungus kingdom causing a fruit rot of apples, pears, plums, peaches and cherries.
This article summarizes different crops, what common fungal problems they have, and how fungicide should be used in order to mitigate damage and crop loss. This page also covers how specific fungal infections affect crops present in the United States.
Monilinia oxycocci (Woronin) Honey,, common names cranberry cottonball, cranberry hard rot, tip blight, is a fungal infection of large cranberry and small cranberry. The tips of young flowering shoots wilt before they flower. Fruit that forms on the plant can then be infected by the asexual spores traveling through the plant, causing the berries to harden, turn cottony on the inside, and dry out instead of maturing. The berries are filled with a cotton-like fungus and are generally yellowish with tan stripes or blotches at maturity, making them unmarketable. It results in important economic impacts on many cranberry marshes, particularly in Wisconsin.
Raspberry spur blight is caused by the fungus Didymella applanata. This plant pathogen is more problematic on red raspberries (Rubus idaeus) than on black or purple raspberries. The fungus infects the leaves first and then spreads to the cane. It causes necrotic spots on the cane near the base of the petiole attachment. Raspberry spur blight can cause a significant reduction in yield, fruit blight, premature leaf drop, and weak bud and cane growth. The magnitude of damage is not clearly understood in the United States, however, studies from Scotland suggest damage to the cane itself is limited. The disease has minor economic impacts by reducing leaves in the summer or killing buds. Major economic damage occurs if the disease manages to kill the entire cane. In the United States, this disease is found in Oregon and Washington.
Ascochyta blights occur throughout the world and can be of significant economic importance. Three fungi contribute to the ascochyta blight disease complex of pea. Ascochyta pinodes causes Mycosphaerella blight. Ascochyta 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.
Phomopsisblight of juniper is a foliar disease discovered in 1917 caused by the fungal pathogen Phomopsis juniperovora. The fungus infects new growth of juniper trees or shrubs, i.e. the seedlings or young shoots of mature trees. Infection begins with the germination of asexual conidia, borne from pycnidia, on susceptible tissue, the mycelia gradually move inwards down the branch, and into the main stem. Management strategies mainly include removing and destroying diseased tissue and limiting the presence of moisture on plants. Junipers become resistant to infection as they mature and the young yellow shoots turn dark green. Preventive strategies include planting only resistant varieties and spraying new growth with fungicide until plants have matured.
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.
Cherry leaf spot is a fungal disease which infects cherries and plums. Sweet, sour, and ornamental cherries are susceptible to the disease, being most prevalent in sour cherries. The variety of sour cherries that is the most susceptible are the English morello cherries. This is considered a serious disease in the Midwest, New England states, and Canada. It has also been estimated to infect 80 percent of orchards in the Eastern states. It must be controlled yearly to avoid a significant loss of the crop. If not controlled properly, the disease can dramatically reduce yields by nearly 100 percent. The disease is also known as yellow leaf or shothole disease to cherry growers due to the characteristic yellowing leaves and shot holes present in the leaves upon severe infection.
Gummy stem blight is a cucurbit-rot disease caused by the fungal plant pathogen Didymella bryoniae. Gummy stem blight can affect a host at any stage of growth in its development and affects all parts of the host including leaves, stems and fruits. Symptoms generally consist of circular dark tan lesions that blight the leaf, water soaked leaves, stem cankers, and gummy brown ooze that exudes from cankers, giving it the name gummy stem blight. Gummy stem blight reduces yields of edible cucurbits by devastating the vines and leaves and rotting the fruits. There are various methods to control gummy stem blight, including use of treated seed, crop rotation, using preventative fungicides, eradication of diseased material, and deep plowing previous debris.
Cladosporium fulvum is an Ascomycete called Passalora fulva, a non-obligate pathogen that causes the disease on tomatoes known as the tomato leaf mold. P. fulva only attacks tomato plants, especially the foliage, and it is a common disease in greenhouses, but can also occur in the field. The pathogen is likely to grow in humid and cool conditions. In 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, although it is originally from South and Central America. The causal fungus of tomato leaf mold may also be referred to as Cladosporium fulvum, a former name.
Shot hole disease 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.
Alternaria leaf spot or Alternaria leaf blight are a group of fungal diseases in plants, that have a variety of hosts. The diseases infects common garden plants, such as cabbage, and are caused by several closely related species of fungi. Some of these fungal species target specific plants, while others have been known to target plant families. One commercially relevant plant genus that can be affected by Alternaria Leaf Spot is Brassica, as the cosmetic issues caused by symptomatic lesions can lead to rejection of crops by distributors and buyers. When certain crops such as cauliflower and broccoli are infected, the heads deteriorate and there is a complete loss of marketability. Secondary soft-rotting organisms can infect stored cabbage that has been affected by Alternaria Leaf Spot by entering through symptomatic lesions. Alternaria Leaf Spot diseases that affect Brassica species are caused by the pathogens Alternaria brassicae and Alternaria brassicicola.
| Authority control databases: National |
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