Khalil I. Al-Mughrabi1
Partner: Potatoes New Brunswick
Abstract: Dry rot caused by various species of Fusarium is a disease of significant importance in potatoes. Field trials were conducted in 2005 and 2006 in Hartland, New Brunswick, Canada to assess the efficacy of Pseudomonas fluorescens and Enterobacter cloacae applied as seed treatment in suppressing Fusarium dry rot of potatoes (cv. Russet Burbank) under field conditions. In 2005, the trial consisted of five treatments namely (1) untreated, uninoculated control; (2) untreated control inoculated with Fusarium sambucinum; (3) seed inoculated with F. sambucinum and treated with P. fluorescens; (4) seed inoculated with F. sambucinum and treated E. cloacae; and (5) seed inoculated with F. sambucinum and treated with the fungicide Maxim® PSP. In 2006, a mustard meal treatment was added. After harvest, tubers were assessed for disease severity of dry rot in addition to other tuber diseases including silver scurf, common scab, and black scurf. In addition, tubers were graded and assessed for total yield, tuber size, tuber weight, tuber number, and miss-shaped tubers. Seed potatoes treated with P. fluorescens significantly reduced the severity of dry rot, common scab and silver scurf diseases. Mustard meal significantly reduced the severity of black scurf and silver scurf. Seed treated with P. fluorescens and E. cloacae produced higher total number of tubers. Total yield was highest for the E. cloacae treatment. The results of this study suggest that mustard meal, P. fluorescens and E. cloacae are viable options for the control of potato tuber diseases. This is the first study to investigate the effect of these bacteria on potato diseases under field settings.
1Potato Development Centre, New Brunswick Department of Agriculture and Aquaculture, 39 Barker Lane, Wicklow, New Brunswick, Canada E7L 3S4