Seed disinfestation by ozone treatments

Seed contamination by fungi may be dangerous either in the case in which seed is used in sowing either when it is stored as human or animal food. Several plant diseases in horticultural crops derive from infected seed that represents a carrier of perpetuation of pathogens infections: for each species plant is known at least one disease transmissible by seed. Superficial contamination of seed for human or animal feeding during storage and marketing derives from infections produced in field and from saprophytic fungi as Aspergillus spp. Penicillium spp and Fusarium spp. that produce dangerous metabolites for human or animal health (aflatoxin B1, B2, G1, G2, M1, ocratoxin A, zearalenone and fumonisin). This work reports results from two experimental trials carried out using ozone treatments in seed disinfestation. A trial was undertaken on a local variety of pea seed collected from horticulturists, in a field in Southern Italy, that produce seeds themselves for sowing. The second trial was carried out on 1-year old stored wheat grain, cv. Cappelli, and Barley grains cv Jiaidor used for food transformation. In both experiments ozone at the concentration of 3% by weight was applied as a mixture of ozone + air for 1, 1.5 and 3 minutes. Untreated seeds were used as control. Treated and untreated seeds were incubated in PDA in Petri dishes for 4 days. The developed fungi were then identified and counted. Fusarium spp, Alternaria spp Penicillium spp and Aspergillus spp. were observed. The longest exposure time was effective in seed disinfestation without influence on germination