Project Number: 6618-22000-034-19
Project Type: Trust

Start Date: Mar 09, 2009
End Date: Mar 30, 2010

Objective:
a) Quantify the dynamics of Xcc production on cankered fruit (pre- and postharvest), leaves and stems and identify when postharvest fruit lesions become moribund and cease to produce viable bacteria of Xcc. b) Perform basic identification procedures on the Xanthomonad-like bacteria associated with ageing lesions on fruit ¿ and their possible role in viability of Xcc. c) Provide data that will be of immediate value to the industry and regulatory agencies/export markets for assessing the risk of cankered, postharvest fruit acting as a viable source of canker.

Approach:
a) Establish sampling protocol and collect samples of infected leaves, stems and fruit from the infected groves on a monthly basis, commencing May 2009. b) Quantify Xcc production on 20 individual lesions from each of the sample units (infected leaves, stems and fruit) on each sampling date. Compare these sources of inoculum throughout the season, and contrast any differences that exist. c) Assess proportion of lesions that produce viable Xcc bacteria on all samples. d) Assess production of bacteria on mature, infected fruit at harvest. Quantify bacteria per lesion, and also the proportion of lesions that produce bacteria. e) Treat mature harvested fruit through a commercial packing line three occasions (December 2009, February and April 2010) and sample lesions. Place in storage and quantify Xcc production on 20 individual lesions on a weekly basis for 5 weeks. Quantify bacteria per lesion, and also the proportion of lesions that produce bacteria. f) Perform basic identification procedures for Xanthomonad-like bacteria associated with ageing lesions on fruit ¿ and its possible role. g) Analyze data and compare sources of inoculum throughout the season and contrast viability of bacteria in fruit lesions pre- and postharvest, and identify the point at which the lesions cease to produce viable bacteria on post harvest fruit. h) Provide data that will be of immediate value to the industry in forming the basis for developing rational regulation for national and international markets for the trade in fresh fruit from Florida.