The efficacy of different seed treatments on tomato bacterial speck disease caused by Pseudomonas syringae pv. tomato

Bacterial speck of tomato caused by Pseudomonas syringae pv. tomato is a bacterial disease which reduces marketability and yield capacity of tomatoes. Occurrence of the pathogen in Turkey is known since 1970s. The pathogenic bacterium causes significant losses in either commercial nurseries, greenhouses or tomato fields. After first disease symptoms observed in emerging seedlings, contaminated seedlings are withdrawed from the market and destroyed. The most critical point in nurseries is to eliminate the seeds from pathogen contamination before planting the seeds. When economical losses are considered, the effective seed treatments can be used by commercial nurseries and seed companies for eliminating the pathogen inoculum in disease management were investigated in this study. The efficacy of 12 different seed treatments (sodium hypocloride, copper acetate and streptomycin sulphate) on artifically contaminated tomato seeds (cv. H-2274) in distinctive doses and periods were studied. The effect of seed treatments on disease incidence, disease severity and seed germinations were investigated. In first experiment, seed treatments were inhibited the disease incidence and disease severity by 73-100% and reduced the seed germinations by 2-21%. In second experiment, the disease incidence was reduced by 45-100%, disease severity by 33-100% and seed germinations were diminished by 1-8%. According to those three criteria, it was demonstrated that hot water treatment was the most effective seed treatment. Dipping seeds in 0.2% copper acetate for one or three minutes, 2% NaOCI for five minutes were determined as successful other seed treatments.