Since this electronic site is being developed, Weeds of the West is an excel lent book that contains phots of mature plants, flowers, and distinctive characteristics. This text can be purchased at bookstores or through the respective Extension Services within each state. Weed control practices in vegetables include management of rotations, prevention, cover crops, plowing, cultivating, row spacings, flaming, using herbicides, and integration into various tillage systems including minimum-till. Because management prac tices differ for various crops and production regions, soil types, and cropping systems, producers must gather information about each cultural practice and integrate it into their personal management scheme. Rotations of crops and weed control practices are fundamental for managing weeds over time.
Crop rotations disrupt weed life-cycles, especially when differences are maximized.
Planting wheat in the fall or managing a gr ass seed crop followed by a brief rotation with annual vegetable crops will disrupt the weed life-cycle and reduce infestations. Managers also must realize that repeated use of the same or similar weed control practice will result in a shift toward tolerant weeds or resistant biotypes that require additional control over time. Resistant biotypes occur when the same or similar h erbicide is applied repeatedly over several years. The weed adapts by creating a subtle biochemical or genetic difference that changes binding or metabolism of the herbicide resulting in survival when future treatments are applied. Repeating tillage pra ctices also enhances growth and spread of certain weeds, especially perennials like yellow nutsedge.