U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PubAg

Main content area

Sweetpotato weevil (Cylas spp.) resistance in African sweetpotato germplasm

Author:
Harriet Muyinza, Herbert L. Talwana, Robert O.M. Mwanga, Philip C. Stevenson
Source:
International journal of pest management 2012 v.58 no.1 pp. 73-81
ISSN:
1366-5863
Subject:
Curculionidae, Cylas formicarius elegantulus, cracking, cultivars, field experimentation, germplasm, insect pests, laboratory experimentation, landraces, plant breeding, progeny, resistance mechanisms, rooting, roots, screening, soil, sweet potatoes, Africa
Abstract:
Host-plant resistance could be a useful tool for managing the weevils Cylas puncticollis and C. brunneus, which are major insect pests of sweetpotato in Africa. There is currently little information on existing resistance mechanisms against Cylas spp. in African cultivars, except where lower levels of weevil damage were attributed to escape due to deep rooting and reduced soil cracking, limiting the exposure of roots to weevils. Here, we evaluate weevil resistance in 134 sweetpotato cultivars and landraces over two seasons in two agroecologically diverse locations. Several sweetpotato cultivars, including New Kawogo, expressed resistance to Cylas spp. The resistance characteristics have been demonstrated in previous laboratory experiments to be quantifiable and thus potentially useful in targeted plant-breeding against Cylas spp. We showed external root and stem base damage to be an accurate quantitative indicator of internal root damage, offering rapid and accurate evaluation of resistance in field trials for screening. Moreover, weevil resistance can be assessed earlier in plant development, so saving time in the selection of the progeny from breeding programmes.
Agid:
347831