PCA Exam- Weeds

PCA Exam- Weeds What are weeds plants that interfere with the growing of crops or ornamental plants or cause other types of damage Invasive weeds cause ecological damage by displacing native plants and the organisms that feed on them; compete with ag crops for water and nutrients, causing them to become more susceptible to disease or other pests True weeds adapt well to local climates, soils, and other external conditions Perennial weeds capable of reproducing through vegetative structures such as stolons, rhizomes, and tubers; cultural activities such as hoeing, mowing, or discing can produce new plants; persistent and hard to eliminate; morning glory Native weeds 3% plants are weeds; no more than 25-35 weeds in one site Weeds and their affects Harbor insects, dry is fire hazard, reduce livestock forage quality and quantity, jeopardize animal and human health, increase the threat of fire or flooding, interfere with recreational activities, lower land value, change soil fertility, increase erosion, leaf litter IDing weeds recognize differences in flowers, leaves, stems, roots, fruit, seeds, and special structures such as tubers and rhizomes Dicots broadleaves, two seedling leaves (cotyledons), netlike veins, herbaceous or woody plant Monocots single grasslike leaf in seedling, veins that run parallel, grasses, sedges, and rushes Bryophytes mosses and liverworts; lack a vascular system; occasional pests Algae nonflowering aquatic plants that clog storm drains, stream, lakes, ditches and rice fields; carryout photosynthesis; lack true stems, leaves, and flowers; reproduce through cell division or production of spores Best weed stage to kill