What is a Weed? (Introduction)

A weed is a plant considered undesirable in a particular situation; a plant in the wrong place. The term weed has no botanical significance, because a plant that is a weed in one context is not a weed when growing in a situation where it is in fact wanted, and where one species of plant is a valuable crop plant, another species in the same genus might be a serious weed.

There are numerous definitions of a weed, including;

• A plant out of place and not intentionally sown.
• A plant growing where it is not wanted.
• A plant whose virtues have not yet been discovered.
• Plants that are competitive, persistent, pernicious, and interfere negatively with  human activity.

No matter what definition is used, a weed is a plant whose undesirable qualities outweigh its good points, according to man. Our human activities create weed problems since no plant is a weed in nature. Though we may try to manipulate nature for our own good, nature is persistent. Through the manipulation process, certain weeds are controlled, while other more serious weeds may thrive because favorite growing conditions for them also have been met.

Weeds are naturally strong competitors and those weeds that can best compete always tend to dominate. Both humans and nature are involved in plant breeding programs. The main difference between the two programs is that man breeds plants for yielding, while nature breeds plants for survival.