Simulation of Spring-Seeded Smother Plants for Weed Control in Corn (Zea mays)

Abstract

Field experiments were conducted to determine the effect of a short-term spring-seeded smother plant on corn development and weed control. Yellow mustard was managed to provide interference durations of 2,4,6, or 8 wk, and maximum height of 10 or 20 cm. Three yellow mustard planting patterns and eight seeding rates were evaluated during 1989 and 1990 at St. Paul and Rosemount, MN. Yellow mustard seeded at 2120 seeds m−2with an interference duration of 4 wk and a maximum height of 10 cm decreased corn yield 17% and reduced weed dry weight 4 wk after yellow mustard emergence an average of 66%. Yellow mustard with a 2-wk interference duration did not reduce weed dry weight. Yellow mustard seeded at 2120 seeds m−2with a 6- or 8-wk life cycle and 10-cm height reduced weed dry weight at the end of the interference period an average of 82% but delayed corn silk emergence an average of 5.3 d and reduced average grain yield 19%. Increasing yellow mustard height from 10 to 20 cm delayed corn silk emergence and reduced grain yield but did not decrease weed dry weight. Yellow mustard with an interference duration of 4 wk and a maximum height of 10 cm, seeded over the corn row at 530 seeds m−2, reduced weed dry weight 4 wk after mustard emergence an average of 51%, and resulted in an average corn grain yield reduction of 4%, compared with corn grown in monoculture averaged over weedy and weed-free treatments. These results suggest that it may be possible to develop spring-seeded smother plants that reduce weed biomass up to 80% but have only a small impact on corn yield.

A Test of Two Annual Cover Crops for Controlling Phalaris arundinacea Invasion in Restored Sedge Meadow Wetlands

“…Cover crop suppression of desired species, as observed here and in agriculture (Lanini et al 1991; Hoffman et al 1993; De Haan et al 1994), may often limit cover crop success. Nevertheless, cover crops have the potential to control invasive species and encourage native community establishment in a variety of restored ecosystems.…”

Native cover crops suppress exotic annuals and favor native perennials in a greenhouse competition experiment

“…Unfortunately, cover crops often fail to improve the desired species success, in part because they do not act selectively. Cover crops that are strong enough competitors to control the invasive species also tend to strongly suppress the desired species, whereas cover crops that do not strongly suppress the desired species also tend not to suppress the invasive species (Lanini et al 1991;Hoffman et al 1993;De Haan et al 1994;Perry and Galatowitsch 2003;Ledgard and Davis 2004).…”

Light competition for invasive species control: A model of cover crop–weed competition and implications for Phalaris arundinacea control in sedge meadow wetlands

“…In ecological restoration, cover crops are often annuals or short-lived perennials (Morgan, 1997;Welling & Becker, 1993), and usually die within the first few growing seasons. In agriculture, cover crops are typically killed or harvested at some time during the growing season (Clark et al, 1994;DeHaan et al, 1994;Hoffman et al, 1993). We simulated cover crop mortality in the model by setting B cover = 0.1 at different times during the 140-day growing season.…”