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Disease Note. First Report of Heterodera gambiensis on Pearl Millet in Niger. S. B. Sharma, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Andhra Pradesh 502 324, India. F. Waliyar, and B. J. Ndunguru, ICRISAT Sahelian Center, BP 12404, Niger. Plant Dis. 74:938. Accepted for publication 10 April 1990. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0938D. In July 1989, juveniles of Heterodera sp. were isolated from soil
samples collected from a field intercropped with groundnut (Arachis
hypogaea L.) and pearl millet (Pennisetum glaucum (L.) R. Br.) in
Maradi, Niger. Subsequent soil and root samples collected from these
crops revealed white females with egg sacs on the roots of pearl millet.
Brown cysts and second-stage juveniles were extracted from rhizosphere
soil. The nematode density ranged between 0 and 20 cysts
per 100 cm3 of soil. Crop growth was variable in patches. The nematode
was identified as Heterodera gambiensis Merny & Netscher based
on cyst cone top structures and measurements of second-stage juveniles
and males (1). Species identification was confirmed by M. R. Siddiqi,
CABI Institute of Parasitology, England. H. gambiensis has been
recorded on sorghum and pearl millet in parts of Gambia, but this
is the first record of occurrence in Niger. It may be useful to investigate
the involvement of this nematode in the crop growth variability
problem common in Niger. |