Kakuhenzire R.,International Potato Center Uganda |
Lemaga B.,International Potato Center Uganda |
Kashaija I.,Kachwekano ZARDI |
Ortiz O.,International Potato Center |
Mateeka B.,Kachwekano ZARDI
Biopesticides International | Year: 2013
Potato (Solanum tuberosum Lin.) in tropical highlands (TH) is threatened by bacterial wilt (BW) caused by Ralstonia solanacearum (Rs). Technologies for reducing soilborne Rs are imperative in order to maintain supply of BW-free seed for sustainable high potato yield. Thus, experiments were conducted in S.W. Uganda in a BW endemically-infested field at 2200 m above sea level to test the effect of Crotalaria falcata as a component of crop rotation practice, soil fertility improvement and fallowing as a means of reducing or eliminating Rs inoculum in open fields for production of clean potato tubers. A one-year C. falcata fallow reduced BW incidence by > 85% compared to beans (43.9%), maize (37.6%) or natural fallow (27.0%). More than 97% of tubers from plots previously infested with Rs and cropped with C. falcata for 6-12 months had no visible BW symptoms compared with < 50% of tubers from plots continuously planted with potato. Apparently healthy tubers from plots previously planted with C. falcata were free from latent Rs infection but not tubers from plots formally kept under natural fallow for two years, or alternately planted with maize, beans, cabbage and onion. The effects of C. falcata on suppression of foliage BW and latent Rs infection in tubers were evident and profound. Crotalaria falcata can, therefore be included in the crop rotation and land fallowing practice for effective prevention of both visible and latent Rs infection in seed and sustaining high ware potato yield among small holder farmers in tropical highlands. © 2013 (KRF).