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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Disintegration of the Scrophulariaceae. Organism Names see more details is a root parasitic weed mainly on economically important leguminous crops in a large part of the African continent.
No association has been observed between morphological variation, largely in leaf shape, and host preference. This would be cut and the roots destroyed by ploughing when about two months old and when A.
In Botswana, grain or fodder cultivars of pearl millet and bambara, which is not attacked vvogelii the local biotype of the parasite, are potent stimulators of A. Although these accounts include the genus in the family Scrophulariaceae, a sequence analysis of three plastid genes suggested that it should be placed in the Orobanchaceae along with other closely related parasitic genera Olmstead et al. The biology of Alectra vogelii Benth. Tiny seeds are easily spread by wind, surface water flow or in crop seed.
Growth towards the alectrx is a chemotropic response to a concentration gradient of host root exudate Visser, Alectra vogelii alectra vogelii Subject Category: IPM Programmes Integrated control should be built around the use of resistant crop cultivars if possible, or choice of the least susceptible cultivar that is currently available. Magani and Lagoke report that farmers can reduce cowpea infection by A.
Generate a print friendly version containing only the sections you need. Comparative responses of cowpea breeding lines to Striga and Alectra in the dry savanna of northeast Nigeria. Larvae of the moth Stenoptiloides taprobanes feed on the flowers preventing seed production on predated flowers Parker and Riches, It is closely associated with cultivation, is occasionally found associated with weeds of fallows but rarely in natural vegetation.
Both types of flowers can be found in a group of plants. 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.
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Below ground, bright orange stems are attached to host roots by a spherical haustorium up to 2 cm in diameter. Risk of Introduction Top of page Although A.
Author Author Serial Subject. Flowers appear singly on a short stem in the axils of upper leaves or bracts.
Synthetic analogues of strigol, including GR7 and GR24, are effective stimulators of the germination of A. The accidental introduction of the related Striga asiaticaa noxious parasitic weed of maize and other cereals, into the USA in the s Parker and Riches, demonstrates that long-distance spread of the tiny seeds vogellii these root parasites is possible.
Alectra vogelii (yellow witchweed)
Despite the similarly of life cycle to Striga species which are listed, and potential for crop damage, A. The stems and leaves, which can be 1. The dust-like seeds have a complex structure. Yellow witchweed on cowpea. Hand-pulling should be carried out on lightly infested areas, particularly in fields which have not previously had a history of infestation.
However, only a small proportion of plants are attacked so the overall effect on seed vogelij is probably not significant. The dust-like seeds have a complex structure. Alevtra new parasitic weed Alectra vogelii similar to Striga on groundnut in Ethiopia. This is to ensure that we give you the best experience possible.
Hand-pulling should be carried out on lightly infested areas, particularly in fields which have not previously had a history of infestation. The tubular corolla is formed of five petals fused towards the base, so that the flower is bell-shaped when open.
Contact between parasite and host is quickly established. Breeding cowpea varieties for resistance to Striga gesnerioides and Alectra vogelii. Please sign in to access your subscribed products. Improved cowpea cultivars which combine resistance to A. Tropical Agriculture, 48 2: Flowers appear singly on a short stem in the axils of upper leaves or bracts.
Hutchinson and Dalziel, Kureh I; Alabi SO, However, in his taxonomic revision of the genus, Melchior considered these all to be characteristic of A.
Chancellor College, University of Malawi, Engler split the species into A.