Potato cultivar response to late blight as affected by clonal selection andin vitro culture

Response to foliar late blight for Superior and Sebago was not affected by the two potato seed selection and multiplication methods. Kennebec and Russet Burbank potato plants derived throughin vitro tissue culture techniques had significantly more late blight damage on only 4 of 7 and 2 of 7 observation dates, respectively, than plants derived through a clonal selection system. In practical terms, the disease response differences between the two seed propagation methods were minimal. Similarly, disease response differences among the 2 and 3 years of field multiplication for Russet Burbank and Kennebec, respectively, did not demonstrate any significant disease response trends. In general,in vitro culture plots had slightly higher yields than clonal plots but only Kennebec had a significant yield response. The incidence of late blight storage rot was generally not significantly different but clonally selected Kennebec potatoes had significantly more disease than those produced throughin vitro culture.