Weed Technology (2009) 23, 371-378

Randall S. Currie, Norman L. Klocke, Holly N. Davis and Lawrent L. Buschman (2009)
Multiple season reductions in herbicide, downy brome (Bromus tectorum), and irrigation in corn
Weed Technology 23 (3), 371-378
Abstract: This research explored the use of downy brome (BROTE) as a cover crop in irrigated corn. Although BROTE is a difficult weed to control, it could not be maintained as a cover crop in no-till irrigated corn for more than one season. A 10-fold reduction in BROTE occurred in the second year of corn. By the fourth year, only one BROTE plant could be found at the two locations. Because BROTE did not persist across years, soil coverage decreased 5 to 18% in the later location-years. At one location, normal herbicide rates decreased Johnsongrass biomass more than 22-fold both years it was applied. Increasing herbicide input decreased Palmer amaranth density more than 3-fold, but only in a single location-year. In three of six location-years, level of herbicide input had no significant effect on evapotranspiration (ET). Increased BROTE biomass decreased ET 0.033 to 0.083 cm/d during the first season at both locations. Increased irrigation increased corn yield by 240 to 1,900 kg/ha in five of six location-year combinations. Half rates of in-season herbicides reduced yield only in one of six location-years. High BROTE density reduced ET but did not translate into increased crop yield. In three of six location-year combinations, high BROTE density decreased yield by 300 to 1,000 kg/ha. In a single location-year, increased surface residues provided by BROTE increased yield by 560 kg/ha. Increased irrigation inputs decreased water use efficiency (WUE) by 6.3 kg/ha-cm in a single location-year and increased WUE by 10.8 to 121.6 kg/ha-cm in four of six location-years. Increased herbicide inputs increased WUE by 10.3 kg/ha-cm in one location-year. BROTE density had no significant effect on WUE at location 1. At location 2 in the first 2 yr, WUE was increased 9.4 to 22.2 kg/ha-cm.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Randall S. Currie, Lawrent L. Buschman

Research topic(s) for pests/diseases/weeds:
control - general
environment - cropping system/rotation

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Sorghum halepense (weed)	Maize/corn (Zea mays)
	Amaranthus palmeri (weed)	Maize/corn (Zea mays)