Scientists have found that hot molasses could be key to controlling soil pests, allowing farmers to grow peppers and tomatoes in Florida without using the dangerous fumigant pesticide, methyl bromide. Ending reliance on methyl bromide has been particularly tricky in the sunshine state, where mild winters offer safe harbor for pests and sandy soils can make organic options a challenge. Nonetheless, innovative scientists and farmers are creating ways to grow food without pesticides. The March 2011 edition of Agricultural Research, published by USDA, has the story.
At a Fort Pierce lab, scientists are raising bell peppers and eggplant using poultry litter, molasses and anaerobic soil disinfestation (ASD). Acccording to the USDA:
In ASD, a carbon source — in this case molasses — is added to stimulate microbial activity, and the soil is covered with a clear plastic tarp. The topsoil is saturated with water and allowed to heat. The sun-drenched tarp 'cooks' the weed seed in the soil, and the carbon and water increase microbial activity and create anaerobic conditions conducive to pest control.
Scientists found that the ASD treatments killed soil pathogens, and that the molasses and poultry litter controlled nematodes and grass weeds just as well as methyl bromide.
The research is of interested to farmers looking for effective and affordable ways to control pests without methyl bromide or devastatingly toxic alternatives like methyl iodide, a pesticide considered by scientists to be "one of the most toxic chemicals on earth."