Submitted to: Washington State Weed Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: October 10, 2007
Publication Date: November 1, 2007
Citation: Boydston, R. A. Control strategies for Nutsedge and Nightshade. 57th Annual Washington State Weed Conference. Conference abstracts. pp. 21. 2007. Technical Abstract: Yellow nutsedge is a perennial weed that is difficult to control in several crops once established. It is particularly problematic in onion production. Yellow nutsedge reproduces and is dispersed primarily by tubers that are formed at the apical ends of underground rhizomes. Tubers may remain viable for 1to 3 years providing an effective means of survival. It often establishes first in moist areas on field margins and is rapidly spread via field equipment. Yellow nutsedge management requires a systematic, multi-tactic approach throughout the entire crop rotation. Three annual nightshade species are predominant in Washington State; hairy nightshade, cutleaf nightshade, and black nightshade. Nightshade germination is favored by tillage and reduced tillage systems often suppress the weed. Nightshade is frequently a problem in closely related potato and hosts many disease, insect, and nematode pest of potato. Besides the typical competition effects of the weed reducing crop yields, nightshade berries can contaminate pea and bean crops reducing crop quality. Several crops including corn, beans, and wheat have good nightshade control options including herbicides and/or cultivation. Plant identification, biology, and control strategies for yellow nutsedge and nightshade species will be discussed.