Turf & Ornamental Weed Management Principles Latest Update Graded A+

Turf & Ornamental Weed Management Principles Latest Update Graded A+ Integrated Weed Managment (IWM) Control Methods Regulations, Environment, Economics (Prevention, Mechanical, Cultural, Chemical) Origin of Weeds Weeds are classified as native or introduced according to their origin. Plant origin may determine weed managment strategies. Native Weeds Plants that have historic origins in the area and were not introduced by human activity. Introduced Plants Came from other parts of the country or world through human activities, animal movements, and water flow. Most problem weeds are introduced plants by crop seed, hay, straw, and ship ballast water. Escaped Plants Were intentionally introduced by humans as crops, forage, or ornamentals, and have subsequently spread beyond their intended areas. (English Lawn Daisy, Scotch Broom) (How weeds Spread) Weeds spread when seeds or growing plant parts (stems, roots, rhizomes) are moved or carried into new territory. Some invading weed species have evolved special seed shapes or structures to aid their movement by wind, water, or animals. Also many plants have vegetative parts the resprout new roots or shoots. If these plant fragments are carried into new areas, they may grow and start new infestations. Wind (How weeds Spread) carries many seeds to new areas. Some weedsm such as dandelions, have a parachute like attachment that carries the seed in the wind. For other weeds such as kochia, Russian thistle, and some mustards, the entire plant moves or tumbles with the wind, dropping seeds as it rolls. Water (How weeds Spread) From rain or irrigation and surface runoff also transports many seeds. Some seeds have an oily coating or an air bladder to aid flotation. Rivers, streams, and irrigation canals move large numbers of seeds. Mammals, Birds and Humans (How weeds Spread) Carry seeds on their bodies, dropping them into new areas. Plants have seed shapes (BURS, HOOKS, BARBS) that cling to feathers, hair and clothing. Wild or domestic animals ingest and excrete some seeds that survive and germinate after passing through an animal's digestive tract. Weed Seed Dissemination People unintentionally move and introduce weeds over long distances. Equipment (for example, work trucks, cultivators, mowers, recreational equipment and automobiles) carries seeds to new sites. Some weeds develop from seeds introduced in contaminated topsoil, manure, compost, mulch, turfgrass seed or sod. Weed Establishment and Persistence Weeds rapidly become problems in ornamental beds and turf where the grounds is disturbed or where plants are weakened, such as construction areas, heavy foot traffic areas, scalped turf, or edges of plantings. Weeds do not compete well in healthy, vigorously growin turf or ornamental plantings, or where desirable plants shade the soil. Once established, weeds produce large numbers of seed, ensuring their survival. Weed seeds, depending on the species, can remain dormant in the soil from a period of a few months to many decades. This long seed viability helps guarantee weed survival. Because weeds can produce high numbers of seed and many weed seeds can survive in the soil for years, weed managment must be planned and carried out for years. Weed Classification and Life Cycles: two major groups Grasses and Broadleaves Grasses Have only one seed leaf. Leaves are narrow and upright. Leaf veins run parallel to leaf margins. Most grasses have fine and branching (fiborous roots). SEDGES differ from grasses in that they often have triangular shapes stems rather than round or obal ones, and the leaves extend in three directions. CRABGRASS,