ABSTRACT

Cultivation (tillage) of soil to grow crops disturbs the habitat in which wild plant species are growing. Tillage can destroy the weeds that are obvious on untilled fields. However, tillage can create an environment that is favorable for wild species to emerge as weeds in a crop. Sometimes, disturbing the ground allows dormant seeds to germinate, and plants will emerge that otherwise would not be obviously present. Also, cultivation of land may lead to further dissemination of weeds with the equipment or in other operations involved with crop production. Applications of farm manures and composts and grazing of livestock can spread weed seeds, as viable seeds are carried by each of these materials or vectors. Seeds of weeds growing in crops may be spread by harvesting or harvested with the crops and sown with the crop at planting in the next season. Seeds of crops left in the field after harvest may emerge as volunteer plants, which are weeds, in the following crop.