New Hosts of the Parasitic Flowering Plant, Alectra vogelii, in Malawi.

Alectra vogelii Benth. (Family: Scrophulariaceae) is a vascular hemiparasite of various leguminous crops in Africa, including peanut (Arachis hypogaea), bambara groundnut (Vigna subterranea), cowpea (Vigna unguiculata), common bean (Phaseolus vulgaris), soybean (Glycine max), and mung bean (Vigna radiata) (1). It is a common parasite of peanut in Angola, Burkina Faso, Malawi, Mozambique, Nigeria, Swaziland, Zambia, and Zimbabwe (2). During April and May 2000, A. vogelii was observed parasitizing several wild Arachis species in a field at the Chitedze Agricultural Research Station near Lilongwe, Malawi. These species were part of a germ plasm enhancement program that included A. appressipila (ICRISAT Groundnut Accession number [ICG] 8127), A. batizocoi (ICG 8124), A. benensis (ICG 13215), A. cardenasii (ICG 13164 and 13166), A. correntina (ICG 8918), A. duranensis (ICG 13200), A. helodes (ICG 8955 and 14917), A. hoehnei (ICG 13228), A. magna (ICG 8960), A. pintoi (ICG 13222 and 14914), A. stenosperma (ICG 13172 and 13223), and A. valida (ICG 13230). In addition, A. vogelii was observed on four unidentified Arachis species (ICG 13231, 14875, 14888, and 14907). Parasitized plants were less vigorous and connections between A. vogelii and host plants could be observed by carefully removing the soil in the root zone. Mature A. vogelii plants were 0.3 to 0.5 m and had multiple stems branching at the base. Subsoil plant parts were a deep orange color. Flowers were prominent lemon yellow with horseshoe-shaped stigmata and leaves were light green. This is the first report of A. vogelii parasitizing wild Arachis species. References: (1) C. Parker. Crop Prot. 10:6-22, 1991. (2) P. Subrahmanyam. 1997. Parasitic flowering plants. Pages 70-71 in: Compendium of Peanut Diseases, 2 Ed. N. Kokalis-Burelle, D. M. Porter, R. Rodriguez-Kabana, D. H. Smith, and P. Subrahmanyam, eds. American Phytopathological Society, St. Paul, MN.