Control of Soil-borne Pathogens by Soil Fumigation with Paraformaldehyde (Fogidesfarm) as Alternative to Methyl Bromide

摘要

Background and Objective: Soil-borne pathogens cause serious and economic losses in vegetable production worldwide. The present study aimed to evaluate the soil fumigation with paraformaldehyde (Fogidesfarm) as alternative to methyl bromide to control soil-borne pathogens in a series of laboratory tests, greenhouse pot experiment and greenhouse trials. Materials and Methods: In laboratory tests, soil samples were taken from fumigated and non-fumigated infested soils to prepare soil solutions, 1 mL from each were cultured on PDA media and incubated at 25±2°C for 48 h, the number of colonies were counted. Effect of paraformaldehyde on seed germination and plant seedlings was estimated in greenhouse experiments by direct plantation of tomato, cucumber and pepper seeds and transplanting of seedlings of the same vegetable crops in fumigated and non-fumigated soils. Paraformaldehyde was tested for controlling root knot nematode through comparison of root knot formation on tomato roots in both fumigated and non-fumigated soils after four months of planting in greenhouse pot experiment. The statistical analysis for this experiment was mainly depended on percentages, frequencies, means and standard deviations for observations. Results: Laboratory tests indicated decrease of soil pathogens after fumigation from about 4000 CFU g -1 soil to about 40 CFU g -1 soil. Results indicated that seed germination in fumigated soil exceeded 95, where about 95 of seedlings succeeded in all vegetable seedlings in fumigated soils compared with 66 in cumber, 72 in pepper and 62 in tomato seedlings succeeded in the non-fumigated soil. Results also indicated formation of nematode knots on tomato roots in the non-fumigated soils, where no nematode knots appeared on tomato roots planted in the fumigated soil. All experiments indicated high ability of paraformaldehyde to control soil pathogens including root knot nematode on tomato, cucumber and pepper plants without any effect on planted seedlings or seed germination of any of the tested vegetable crops. Conclusion: Results of this study demonstrated that paraformaldehyde (Fogidesfarm) has the potential to be used as an effective and save alternative to methyl bromide.