He looked at a number of alternatives to methyl bromide that would allow containers to be safely re-used. The best proved to be immersing the containers in water at 60 degsC for 10 minutes or more. This treatment killed fungal pathogens as well as weed seeds and pests such as nematodes and western flower thrips.
The equipment required for the job comprises a water tank fitted with a thermostatically controlled heater, a crate in which the used containers are stacked and a forklift truck for handling the crates.
An alternative arrangement for immersing and removing the crates is to place the filled crate on a steel platform that fits inside the tank and can be raised and lowered with a winding mechanism, Talbot suggested.
He advised that the water temperature should be raised above 60 degsC at the start of the treatment as it will drop by about 5 degsC when the crate and containers are immersed. An insulated tank lid will reduce heat loss and water loss due to evaporation. Containers can withstand temperatures up to 80 degsC without risk of distortion, he added.
Any growing medium stuck to the insides of the containers should be knocked out before they are stacked in the crates, Talbot said - otherwise it will build up in the bottom of the tank.
He also warned that the containers should not be rammed together because they will be too difficult to separate after treatment. In addition, they are best stacked in the crates vertically (upside down), not horizontally, to ensure they retain their shape.