Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Plant Pathology


Root-knot nematodes, Meloidogyne spp. have long been a problem on vegetable crops in Botswana. Loss of yield and reduction in quality and marketability of vegetable crops such as beet (Beta vulgaris L.) and carrot (Dancus carota L.) have been reported from school and home gardens as well as from commercial gardens in the country (Nilsson, personal communication). Other major vegetable crops including tomato (Lycopersicon esculentum Mill.) and spinach (Spinacia oleracea L.) are also damaged, but the damage is often overlooked unless plants are pulled and roots examined. Because of a lack of nematologists and plant pathologists, the problem was neglected for some time. It was only recently that interest in root-knot nematodes developed and studies commenced. Incidences of root-knot nematodes on wild hosts and in virgin soil were reported in Botswana. Two species of root-knot nematodes, Meeloidogyne javanica (Treub) Chitwood and M. incognita (Kofoid and White) Chitwood were found on pigweed (Amaranthus thunbergii Moq.), prostrate globe amaranth (Gomphrena celosiodes Matt.) and Pavonia trocumbens Caz. This confirmed earlier reports (Monthshiwa, unpublished) on the existence of root-knot nematodes in virgin soils and the possibility that wild host plants could be the source of these nematodes. The objectives of this study were to determine the host range of the root-knot nematode isolate from Botswana and to study its pathogenicity on different host crops. The effects of soil temperature on reproduction, galling and pathogenicity were also studied.

Library of Congress Subject Headings

Meloidogyne incognita
Soil temperature
Nematode diseases of plants -- Botswana
South Dakota State University Theses



Number of Pages



South Dakota State University