Weed Science (1999) 47, 736-739

P.W. Geier, P.W. Stahlman and J.G. Hargett (1999)
Environmental and application effects on MON 37500 efficacy and phytotoxicity
Weed Science 47 (6), 736-739
Abstract: Experiments were conducted in an environmentally controlled growth chamber to determine the effects of temperature (10/5 or 21/7 C, day/night), soil moisture (7, 14, or 20%), timing (preemergence [PRE] or postemergence [POST]), and rate (9 or 18 g ai ha^-1) of application on MON 37500 efficacy on Bromus secalinus L. and toxicity to Triticum aestivum L. MON 37500 reduced B. secalinus plant density an average of 40% but did not reduce T. aestivum density. PRE treatments reduced B. secalinus density 40% compared to 12% with POST applications when plants were grown at 10/5 C. Soil moisture level also influenced plant density, with 7.9 plants per pot when soil moisture was maintained at 7%, compared to 8.5 plants per pot with 14 or 20% soil moisture. MON 37500 reduced B. secalinus dry weight more at 18 g ha^-1 than at the 9-g ha^-1 rate when grown at 21/7 C, but no rate response occurred at 10/5 C. PRE applications of MON 37500 at 10/5 C decreased B. secalinus dry weight 22% more than PRE applications at 21/7 C or POST applications under either temperature regime. However, PRE applications of MON 37500 at 21/7 C decreased T. aestivum biomass an average of 16%, compared to 3% or less with other treatments. At 21/7 C, B. secalinus dry weight decreased 46% as soil moisture increased from 7 to 20%. Bromus secalinus was 10 to 12% less susceptible to MON 37500 when grown at 7% soil moisture at 10/5 C than when grown at the same temperature at 14 or 20% soil moisture. Triticum aestivum injury was greater at 20% soil moisture under each temperature regime.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Patrick W. Geier, Phillip W. Stahlman

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Bromus secalinus (weed)	Wheat (Triticum)