Plant Pathology Journal1812-53871812-5425Asian Network for Scientific Information10.3923/ppj.2010.65.72OlanyaO.M. PorterG.A. LambertD.H. LakinR.P. StarrG.C. 2201092The aim of this research was to evaluate the effects of irrigation and soil management on potato tuber diseases. Supplemental irrigation, soil amendment and crop rotation can improve potato growth and tuber yield under drought stress conditions, but may also increase potato tuber diseases. The effects of irrigation, soil amendment and crop rotation on the incidence of tuber diseases were quantified from 1994 to 1997 in potato plots. Surface sprinkler irrigation was applied each year, based on tensiometer or moisture block readings deployed in field plots. Black scurf (Rhizoctonia solani), black dot (Colletotricchum coccodes), silver scurf (Helminthosporium solani) and common scab (Streptomyces scabei) diseases were quantified on potato tubers randomly sampled at harvest and kept at storage temperature of 7.2°C before visual disease assessment. The incidence of tuber diseases varied among irrigation treatments, crop rotations and soil amendments. The mean incidence of black scurf, silver scurf and black dot ranged from 3-18, 2-33 and 4-7%, in best, un-irrigated and reduced irrigation, respectively. The incidence of back scurf, silver scurf and black dot diseases ranged from 2.4-10, 0.8-21 and 1-31% on potato tubers grown in plots under green manure rotation crop (peas/vetch). Disease incidences on tubers were 1-28, 0-35 and 2-16% for black scurf, silver scurf and black dot, respectively; when potato plants were grown under small-grain rotation. Soil amendments had significant (p<0.05) effects on the incidences of silver scurf disease in 1997 and black dot disease in 1996 and 1997. The interactions of soil amendment with irrigation resulted in significant effects on black scurf incidence in 1994. This research implied that water application may lead to increases in some potato tuber diseases, however; crop rotation and soil amendment may reduce the incidences of selective potato tuber diseases, depending on the type, duration or frequency of supplemental irrigation.]]>Adams, S.S. and W.R. Stevenson,199067311Adams, M.J., P.J. Read, D.H. Lapwood, G.R. Cayley and G.A. Hide,1987110287294Carling, D.E., R.H. Leiner and P.C. Westphale,1989Rhizoctonia solani AG-3.]]>66693701Davis, J.R. and R.E. McDole,19791979pp: 686pp: 686Errampalli, D., J.M. Saunders and J.D. Holley, 2001Helminthosporium solani) as an economically important disease of potato. ]]>50141153Frank, J.A. and H.J. Murphy,197754315322Hide, G.A. and J.P. Firmager,1989Rhizoctonia solani) disease of potatoes.]]>327586Honeycutt, C.W., W.M. Clapham and S.S. Leach,1996734561James, W.C.,1971Pages: 90Pages: 90Johnson, D.A. and E.R. Miliczky,1993777479Lapwood, D.H., L.W. Wellings and J.H. Hawkins,1973Streptomyces scabies): Final experiment and conclusions.]]>223541Larkin, R.P. and C.W. Honeycutt,2006966879Olanya, O.M., D.H. Lambert and G.A. Porter,200683397408Olanya, O.M., G.C. Starr, C.W. Honeycutt, T.S. Griffin and D.H. Lambert,20072614121421Olanya, O.M., D.H. Lambert, A.F. Reeves and G.A. Porter,2007Rhizoctonia solani AG-3 in Maine.]]>42409418Peters, R.D., A.V. Sturz, M.R. Carter and J.B. Sanderson,200484397402Raniere, L.C. and D.F. Crossan,1959Colletotrichum phomoides.]]>497274Read, P.J. and G.A. Hide,1988Colletotrichum coccodes (Wallr.) Hughes) and its development during storage.]]>31493500Rotem, J. and J. Palti,19697267288Rotem, J., J. Palti and J. Lomas,197060839843Scholte, K., Veenbass-Rijks, J.W., and R.E. Labruyere,1985Streptomyces spp, Colletotrichum coccodes, Fusarium tabacinum and Verticillium dahliae on plant growth and tuber yield.]]>28331348Starr, G.C., D. Rowland, T.S. Griffin and O.M. Olanya,20085292300Olanya, O.M., G.A. Porter and D.H. Lambert,201042936Scott, G.J., M.W. Rosegrant and C. Ringler,200025561597Powelson, M.L., K.B. Johnson and R.C. Rowe,19931993pp: 149-158pp: 149-158