Ditylenchus dipsaci is a plant pathogenic nematode which primarily infects onions and garlic. It is commonly known as the stem nematode, the stem and bulb eelworm or onion bloat (in the United Kingdom).

Distribution

This nematode is found in most temperate areas of the world including Europe and the Mediterranean region, North and South America, northern and southern Africa, Asia and Oceania, but is not usually found in tropical regions.

Morphology and biology

These nematodes are microscopic worms approximately 1.5 millimetres long. They penetrate into plants from either the soil or infested planting material and occasionally from seeds. They live between the cells of onion or garlic leaves and between the scales of the bulbs where they feed on cell sap and multiply. The female lays 250 eggs during a season and six generations may develop under optimum conditions when the temperature is in the range 15-20°C. As the number of nematodes increase, visual signs begin to occur. Onion leaves start to curl, garlic leaves become yellow and die, bulb scales are loosened and bulb necks become cracked. Development continues in infested bulbs during storage. This nematode is not restricted to onions and garlic. Its other plant hosts include peas

PEAS

P.E.A.S. is an acronym in artificial intelligence that stands for Performance, Environment, Actuators, Sensors.-Performance:Performance is a function that measures the quality of the actions the agent did....

, beetroot

Beetroot

The beetroot, also known as the table beet, garden beet, red beet or informally simply as beet, is one of the many cultivated varieties of beets and arguably the most commonly encountered variety in North America, Central America and Britain.-Consumption:The usually deep-red roots of beetroot are...

, vegetable marrow, pumpkin

Pumpkin

A pumpkin is a gourd-like squash of the genus Cucurbita and the family Cucurbitaceae . It commonly refers to cultivars of any one of the species Cucurbita pepo, Cucurbita mixta, Cucurbita maxima, and Cucurbita moschata, and is native to North America...

, rhubarb

Rhubarb

Rhubarb is a group of plants that belong to the genus Rheum in the family Polygonaceae. They are herbaceous perennial plants growing from short, thick rhizomes. They have large leaves that are somewhat triangular-shaped with long fleshy petioles...

, and ornamental bulbs

Bulb

A bulb is a short stem with fleshy leaves or leaf bases. The leaves often function as food storage organs during dormancy.A bulb's leaf bases, known as scales, generally do not support leaves, but contain food reserves to enable the plant to survive adverse conditions. At the center of the bulb is...

. Some weeds also act as hosts including Stellaria media, Linaria vulgaris

Linaria vulgaris

Linaria vulgaris is a species of toadflax , native to most of Europe and northern Asia, from the United Kingdom south to Spain in the west, and east to eastern Siberia and western China...

, Polygonum aviculare

Polygonum aviculare

Polygonum aviculare or Common Knotgrass is a plant related to buckwheat and dock. It is also called birdweed, pigweed and lowgrass. It is an annual found in fields and wasteland, with white flowers from June to October....

, Fallopia convolvulus and Galium aparine

Galium aparine

Galium aparine is a herbaceous annual plant of the family Rubiaceae. It is native to North America and Eurasia. It has several common names, including Cleavers, Clivers, Goosegrass, Stickywilly, Stickyjack, Stickyweed, Stickyleaf, Catchweed, Robin-run-the-hedge and Coachweed.-Growth:The long stems...

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External links

• Ditylenchus dipsaci's photos