The Researchers from the US Department of Agriculture’s (USDA) Agricultural Research Service (ARS) have made an interesting and noteworthy discovery concerning the use of soil bacteria in controlling crop pests. Michael Blackburn, an entomologist at the ARS Invasive Insect Biocontrol and Behavior Laboratory in Beltsville, Md., and his colleagues recently found that pest-eliminating strains of soil bacteria with a certain type of enzyme survive better than strains without the enzyme, which means they are ultimately more effective at eliminating pests without the need for much human intervention.
Published in the journal Biological Control, the results of the study represent a significant milestone in understanding natural bacterial pest control. The findings not only expand the viability of using soil bacteria in commercial crop pest-control applications, but they also solidify the importance of natural soil bacteria in balancing a crop or garden environment, without the need for toxic pesticides.
It is already known that Bacillus thuringiensis (Bt), a naturally-occurring soil bacteria, is effective at eliminating gypsy moths, tent caterpillars, leaf rollers, canker worms and other crop pests. But many strains of this bacteria seem to last for only one generation of pests before dying out and requiring reapplication. But Bt strains that produce an enzyme called urease tend to actually survive and proliferate better when fed to pests, and they last for multiple generational cycles.
When researchers fed urease-containing Bt strains to gypsy moth larvae, the larvae died as they normally would. But after grinding up the dead larvae and analyzing it, the team found that the bacteria survived, allowing it to be fed to the next generation of larvae as well. Each time the urease-containing Bt was consumed by the moths, it continued to survive and spread from generation to generation.
The Bt strains used as part of the study, as well as thousands of others, are absolutely vital for the health and vitality of plants and crops. These bacteria exist naturally in soil, and they help to protect crops from invaders and promote the uptake of important nutrients into plants.
But the chemical pesticides and herbicides used in modern agriculture are destroying this necessary soil bacteria, and replacing it with dead, toxic soil. As these chemical applications destroy all living bacteria in soil, ever more chemical interventions are required just to keep plants growing at all, let alone absorbing any sort of usable nutrients .
The overuse of pesticides and herbicides, whether in conventional or genetically-modified (GM) crop cultivation, ends up causing not only serious pest problems, but also the out-of-control growth of superweeds. It is a highly-damaging, unsustainable system that could be completely avoided if soil was cultivated to promote the growth and proliferation of beneficial soil bacteria.
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