Summary
Weed species in the Solanaceae (nightshade) family cause some of the most serious weed-related problems in Pacific Northwest agriculture. Nightshade control is difficult because the weeds are so widely adapted, their seeds germinate throughout the growing season, and they are tolerant to many commonly used herbicides. Their berries and foliage may be toxic to livestock and humans who inadvertently consume them. The biology and distribution of nightshade species is described, and control of these species in croplands and non-croplands is discussed.