In the initial phases of life on Earth, the prevalence of undesirable plants was
not extensive. Humans developed the practice of differentiating between weeds and
crops based on economic activities. It has been suggested that there are close to 30,000
species that can be classified as weeds. These have co-evolved with crops and are
deemed undesirable because of their capacity to outcompete cultivated plants that are
intended for food and fiber production. It is widely accepted that all primary cultivated
plants have originated from wild weeds. Several plant species that were previously
utilized for ornamental, therapeutic, or feed purposes are currently classified as weeds.
The crop ecosystem has undergone significant changes due to the use of high levels of
fertilizers, intensive cropping practices, and modifications in cropping patterns. Weeds
possess specific characteristics that enable them to thrive and persist in environments
where many cultivated plants would ultimately perish. The existence of weeds may
have multiple effects on human existence. Apart from their economic implications,
these cause hay fever in humans and can also exhibit toxicity in livestock and wildlife.
The impact of weeds on crop productivity varies based on certain factors such as type
of weed species, density of weeds, duration of weed competition, and method of
cultivation.
Keywords: Agriculture, Economy, Management, Weeds.
