Yellow nutsedge (Cyperus esculentus L.)
Perennial. Emerges in the spring, flowers in the summer, and sets seed late-summer to fall. Aboveground material and rhizomes die after a killing frost; tubers survive through the winter.
Tubers can produce shoots from as deep as 31 1/2 inches below the soil surface.
Mode(s) of Reproduction: Reproduction primarily occurs by tubers (i.e. nutlets). Some reproduction takes place via seeds, though viability is low.
Dispersal Mechanisms: None.
Longevity: At a depth of 2 inches, seed viability decreases by 90% in less than 2 years. Tubers can remain viable for up to 3 1/2 years in the soil.
Dormancy: Tubers are mostly dormant during the season they are formed. After exposure to cold temperatures and leaching, most of this initial dormancy is broken when temperatures warm the following spring.
Corn yield is reduced by 8% for every 119 shoots per yard2.
Preferred Soil/Field Conditions:
Grows on a variety of soil types and moisture levels, often starting in wet areas and spreading.
Predation/grazing: No information.
Decay: No information.
Other: An indigenous rust (Puccinia canaliculata) was found to successfully control yellow nutsedge, though production problems have stood in the way of commercial use.
Tillage: Tillage every three weeks throughout the season can reduce viability by 80% because tubers are exposed to prolonged drying on the soil surface. Intensive tillage in a three year corn-cotton-peanut rotation reduced yellow nutsedge tubers by 97 to 99% (hand weeding was also done in the cotton).
Rotary Hoeing: Rotary hoeing was a part of the intensive tillage system in the corn-cotton-peanut rotation mentioned above that drastically reduced the number of nutsedge tubers.
Flaming: Not effective.
Crop rotation: Summer fallow allowing for multiple tillage passes and/or herbicide applications is one strategy for nutsedge control.
Differences in corn planting dates do not effect yellow nutsedge biomass or tuber production.
Other: Keeping cultivation and tillage equipment clean will prevent spread to other fields.
Application timing and effectiveness: Several herbicides are labeled for control of nutsedge. Most effective herbicides are usually applied preplant incorporated (PPI) or postemergence (POST). Please refer to E-434, "MSU Weed Control Guide for Field Crops," for herbicide recommendations.