 | This article needs additional citations for verification .(January 2014) |
This article is a list of diseases of cucurbits (Citrullus spp., Cucumis spp., Cucurbita spp., and others).
| | This article needs additional citations for verification .(January 2014) |
This article is a list of diseases of cucurbits (Citrullus spp., Cucumis spp., Cucurbita spp., and others).
| Bacterial diseases | |
|---|---|
| Angular leaf spot | Pseudomonas amygdali pv. lachrymans |
| Bacterial fruit blotch/seedling blight | Acidovorax avenae subsp. citrulli = Pseudomonas pseudoalcaligenes subsp. citrulli |
| Bacterial leaf spot | Xanthomonas campestris pv. cucurbitae |
| Bacterial rind necrosis | Erwinia spp. |
| Bacterial soft rot | Erwinia carotovora subsp. carotovora |
| Bacterial wilt | Erwinia tracheiphila |
| Brown spot | Erwinia ananas |
| Miscellaneous diseases and disorders | |
|---|---|
| Air pollution injury | Ozone, sulfur dioxide and others |
| Bitter fruit | Sunburn injury, physiologic stress |
| Blossom end rot | Physiological disorder, calcium deficiency, moisture imbalance |
| Bottle neck of fruit | Incomplete pollination |
| Measles | Physiological disorder, salt toxicity |
| Sandburn | Physiological disorder |
| Sunscald (fruit) | Excessive or intense direct heat/ solar injury |
| Windburn | Physiological disorder |
| Nematodes, parasitic | |
|---|---|
| Dagger, American | |
| Lesion | Pratylenchus spp. |
| Pin | Paratylenchus spp. |
| Reniform | |
| Ring | Circonemella spp. |
| Root-knot | Meloidogyne spp. |
| Spiral | Helicotylenchus spp. |
| Sting | |
| Stubby-root | |
| Stunt | |
The Cucurbitaceae, also called cucurbits or the gourd family, are a plant family consisting of about 965 species in around 95 genera, of which the most important to humans are:
Cucurbita is a genus of herbaceous vegetables in the gourd family, Cucurbitaceae native to the Andes and Mesoamerica. Five species are grown worldwide for their edible vegetable, variously known as squash, pumpkin, or gourd, depending on species, variety, and local parlance, and for their seeds. Other kinds of gourd, also called bottle-gourds, are native to Africa and belong to the genus Lagenaria, which is in the same family and subfamily as Cucurbita, but in a different tribe. These other gourds are used as utensils or vessels, and their young fruits are eaten much like those of the Cucurbita species.
Plant pathology is the scientific study of diseases in plants caused by pathogens and environmental conditions. Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants. Not included are ectoparasites like insects, mites, vertebrate, or other pests that affect plant health by eating plant tissues. Plant pathology also involves the study of pathogen identification, disease etiology, disease cycles, economic impact, plant disease epidemiology, plant disease resistance, how plant diseases affect humans and animals, pathosystem genetics, and management of plant diseases.
Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of fungi in the order Erysiphales. Powdery mildew is one of the easier plant diseases to identify, as its symptoms are quite distinctive. Infected plants display white powdery spots on the leaves and stems. The lower leaves are the most affected, but the mildew can appear on any above-ground part of the plant. As the disease progresses, the spots get larger and denser as large numbers of asexual spores are formed, and the mildew may spread up and down the length of the plant.
Downy mildew refers to any of several types of oomycete microbes that are obligate parasites of plants. Downy mildews exclusively belong to Peronosporaceae. In commercial agriculture, they are a particular problem for growers of crucifers, grapes and vegetables that grow on vines. The prime example is Peronospora farinosa featured in NCBI-Taxonomy and HYP3. This pathogen does not produce survival structures in the northern states of the United States, and overwinters as live mildew colonies in Gulf Coast states. It progresses northward with cucurbit production each spring. Yield loss associated with downy mildew is most likely related to soft rots that occur after plant canopies collapse and sunburn occurs on fruit. Cucurbit downy mildew only affects leaves of cucurbit plants.
Verticillium wilt is a wilt disease affecting over 350 species of eudicot plants. It is caused by six species of Verticillium fungi: V. dahliae, V. albo-atrum, V. longisporum, V. nubilum, V. theobromae and V. tricorpus. 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.
Rhizoctonia solani is a plant pathogenic fungus with a wide host range and worldwide distribution. It was discovered more than 100 years ago. R. solani frequently exists as thread-like growth on plants or in culture, and is considered a soil-borne pathogen. R. solani is best known to cause various plant diseases such as collar rot, root rot, damping off, and wire stem. R. solani attacks its hosts when they are in their early stages of development, such as seeds and seedlings, which are typically found in the soil. The pathogen is known to cause serious plant losses by attacking primarily the roots and lower stems of plants. Although it has a wide range of hosts, its main targets are herbaceous plants. R. solani is a basidiomycete fungus but the teleomorph stage is not prominent. Occasionally, sexual spores (basidiospores) are produced on infected plants. The disease cycle of R. solani is important in management and control of the pathogen. The pathogen is not currently known to produce any asexual spores (conidia), though it is considered to have an asexual lifecycle perpetuated through sclerotia.
Pectobacterium carotovorum is a bacterium of the family Pectobacteriaceae; it used to be a member of the genus Erwinia.
Podosphaera fuliginea is a plant pathogen that causes powdery mildew on cucurbits. Podosphaera fuliginea and Erysiphe cichoracearum are the two most commonly recorded fungi causing cucurbit powdery mildew. In the past, Erysiphe cichoracearum was considered to be the primary causal organism throughout most of the world. Today, Podosphaera fuliginea is more commonly reported.
A wilt disease is any number of diseases that affect the vascular system of plants. Attacks by fungi, bacteria, and nematodes can cause rapid killing of plants, large tree branches or even entire trees.
Fusarium dry rot is one of the most common potato diseases. It is caused by fungi in the genus Fusarium. This fungi causes a variety of colored rots in potatoes. This pathogen, while having both a sexual and asexual form, stays in an asexual cycle due to the way it spreads. Preferring warmer climates, it is not uncommon to find this pathogen in the northern United States where it has been reported to affect yield as much as 60%.
Thomas Wallace Whitaker was an American botanist and horticulturist who spent most of his career working as a geneticist for the United States Department of Agriculture (USDA). He specialized in the study of economically important plants such as squashes, investigating their systematics and resistance to disease.