Herbicide resistance has become an important constraint on modern agricultural practices. An
alarming increase in weed biotypes that are resistant to herbicides has also been reported.
Opportunity exists for a novel weed management technology which is also compatible with
no-till agricultural practices. Microwave heating can kill both emerged weed plants and weed
seeds in the soil. When the intensity of the microwave fields is moderate plants which have
already emerged are susceptible to microwave treatment. If the microwave field is intense
enough very rapid volumetric heating and some thermal runaway in the plant structures cause
micro-steam explosions in the plant cells which rupture the plant structures leading to
death. Soil treatment requires significantly more energy however there are secondary benefits
for crops growing in microwave treated soil. These include: significant reduction of the
dormant weed seed bank significant reduction of nematode populations significant reduction of
fungal populations better availability of indigenous nitrogen for the plants more rapid
humification and significant increases in crop growth and yield. Microwave weed management and
soil treatment is not restricted by weather conditions therefore the technology may offer
some timeliness and environmental benefits which are yet to be quantified in a cropping
system.
