Sweetpotato infestation by Cylas spp. in East Africa: I. Cultivar differences in field infestation and the role of plant factors
Stathers, T.E., Rees, D., Kabi, S., Mbilinyi, L., Smit, N., Kiozya, H., Jeremiah, S., Nyango, A. and Jeffries, D. (2003) Sweetpotato infestation by Cylas spp. in East Africa: I. Cultivar differences in field infestation and the role of plant factors. International Journal of Pest Management, 49 (2). pp. 131-140. ISSN 0967-0874 (print), 1366-5863 (online) (doi:10.1080/0967087021000043085)Full text not available from this repository.
Sweetpotato weevils (Cylas spp.) constitute a major constraint upon sweetpotato production and utilization world-wide. Attempts to breed for resistance to Cylas spp. have had limited success. However, there are reports of variation in the susceptibility to weevil attack in the
field among cultivars in East Africa. Field trials were conducted at two sites (Ukiriguru and Kibaha) in Tanzania and at one site (Serere) in Uganda to determine the extent to which sweetpotato cultivars presently available in East Africa consistently differ in their susceptibility to field
infestation by Cylas spp. and to identify the plant factors that determine the levels of susceptibility. Several methods to assess levels of field infestation were tested, and their relative merits are discussed. Significant cultivar differences in susceptibility to Cylas spp. infestation were observed for four out of six trials carried out over 2 years. The exceptions were cases where infestation levels were either very low or very high. Linear regression models of infestation suggest that the
following plant characteristics are associated with low susceptibility to Cylas spp. infestation: increased distance of roots from the soil surface, fewer soil cracks, fewer exposed roots and a high foliage yield. Both the
distance of the roots from the soil surface (shortest weevil distance) and foliage yield differ significantly between cultivars. The former cannot be approximated by measurement of root neck length, but must be measured in situ.
|Uncontrolled Keywords:||resistance, plant architecture, pest management|
|Subjects:||S Agriculture > S Agriculture (General)|
S Agriculture > SB Plant culture
|School / Department / Research Groups:||Natural Resources Institute|
|Last Modified:||10 Nov 2011 11:42|
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