ALECTRA VOGELII PDF

Alectra vogelii has been the major constraint known to attack leguminous species especially to cowpea production. Identification of genetic variation of i. Alectra vogelii is a root parasitic weed mainly on economically important leguminous crops in a large part of the African continent. The extremely small seeds. Alectra vogelii (Benth.) is an angiosperm root hemi-parasite attacking C3 legumes in semi arid tropics; cowpea, groundnut, soybean and grams are the most.

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The parasite grows within the host until contact is made with xylem vessels and phloem sieve tube elements of the host stele. The effect of attack by Alectra vogelii Benth. Parasitism of grain legumes by Alectra species Scrophulariaceae. It is closely associated with cultivation, is occasionally found alrctra with weeds of fallows but rarely in natural vegetation.

Alectra vogelii (yellow witchweed)

Studies from these areas show a high incidence of poverty and associated voeglii such as malnutrition among under-5s e. Cultural Control Two options, catch and trap-cropping, are available for reducing bogelii size of the A. However, only a small proportion of plants are attacked so the overall effect on seed production is probably not significant. Timely destruction of legume crop residues is important to prevent parasite seed production after harvest and trap-crops should be included in the rotation to reduce the soil seed bank.

Seeds of the parasite may contaminate grain legume seeds during threshing and be transported to markets or neighbouring farms during local sales. All previous and subsequent major floras for West Africa Hutchinson and Dalziel, and south-eastern Africa Philcox, have maintained the name as A.

When several references are cited, they may give conflicting information on the status. African Journal of Plant Science, 6 3: An assessment of its global invasive potential is given by Mohamed et al. Nutritive value of cowpea. Contact between parasite and host is quickly established. Habitat Top of page A. This would be cut and the roots destroyed by ploughing when about two months old and when A.

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Both types of flowers can be found in a group of plants. Visser, ; Parker and Riches, Larvae of the moth Stenoptiloides taprobanes feed on the flowers preventing seed production on predated flowers Parker and Riches, Journal of Plant Growth Regulation, 11 2: Leaf shape, particularly the nature and extent of toothing along the edge of the lamina, varies considerably.

Notizblatt der botanischen garten und museum Berlin-Dahlem, The distribution in this summary table is based on all the information available. Continuing to use www. History of Introduction and Spread Top of page A. Growth towards the root is a chemotropic response to a concentration gradient of host root exudate Visser, Close Find out more.

With special reference to the germination of its seeds. Little attention has therefore been given to vogeii development of chemical control. Cowpea is the major crop host of A. Organism Names see more detailsplants plants Subject Category: Like most websites we use cookies. As flowering specimens are very leafy and with a similar habit to many free-living plants, people who are not familiar with root hemi-parasites are unlikely to recognize that A.

Plants grow to cm tall, often as a single stem but sometimes branching from near soil level. Flowers appear singly on a short stem in the axils of upper leaves or bracts.

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Tiny seeds are easily spread by wind, surface water flow or in crop seed. Before parasite emergence, aboveground affected cowpea plants may appear wilted.

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Like most websites we use cookies. The species is assumed to have an origin in West Alectea and to have spread with human migrations and along trade routes with cowpea cultivation but no records exist on its first appearance in particular areas.

Description Top of page As flowering specimens are very leafy vogellii with a similar habit to many free-living plants, people who are not familiar with root hemi-parasites are unlikely to recognize that A.

An outer cell layer of the testa is modified into a cone or a ‘trumpet-like’ structure about 1 mm long within which the ‘kernel’ of the seed, measuring about 0. Striga research in Southern Africa and strategies for regionalized control options.

Please enter a valid email address. Up to 10 flowers may open on one day. Tropical Science, 46 3: As flowering specimens are very leafy and with a similar habit to many free-living plants, people who are not familiar with root hemi-parasites are unlikely to recognize that A.

Alectra vogelii Benth.

Close Find out more. Trap-crops produce the Alectra germination stimulant in their root exudates vgoelii are not susceptible to attack by the parasite seedlings. Farming in South Africa, May edition: Plants grow to cm tall, often as a single stem but sometimes branching from near soil level. PCR and gel electrophoresis ran.

No studies on origins or aectra. Hand-pulling should be carried out on lightly infested areas, particularly in fields which have not previously had a history of infestation. Samples from eastern Botswana and northern areas of Northern Province, South Africa attack mung bean in addition to cowpea and groundnut.