Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract Full Text

Weed pests for the farmer, human consumers and animals.


Among the pests, weeds were the first to be effectively controlled by farmers for their harmful effects. It is recalled that the weed damages are not limited to a direct nuisance that affects the quantity produced or because of toxicity from seeds or fragments of certain weeds harvested (Agrostemma githago, datura, castor, crotalaria, galega, Lolium temulentum...) or fodder (groundsel) and play on the safety of the food and feed. Some species are toxic because allergens (ragweed, Heracleum sp...). This toxicity can be indirect when these weeds favor toxic fungi (Claviceps purpurea...) or weaken the plant grown against fungi producing mycotoxins (Aspergillus, Fusarium...). Indirect nuisance also includes seed potential that will require intensive control over many years, or the maintenance of many other pests, bacteria, viruses, fungi or animal pests during the relative crawl space that would be expected with adequate crop rotation. Now, the complexity of natural interactions is no longer the lone problem, weeds bloom may prohibit use for several pesticides if assessments that focus on a possible risk for bees actually turn into binding regulations for insecticides, fungicides and herbicides use on the crop long time before the crop flowering stage.