Physical and Cultural Weed Control Working Group of - European ...

9 th EWRS Workshop on Physical and Cultural Weed Control 70
Samsun, Turkey, 28 – 30 March 2011
shortly after flaming, leaving an appearance of a dead plant (Ascard 1995; Knezevic et al. 2009a,
2009b). However, within a week grass species begin to recover with the growth of new leaves.
Similar responses were also reported for grass type crops compared to broadleaf crops. Teixeira et
al. (2008) demonstrated that soybean flamed at the third trifoliolate stage had higher injury by
broadcast flaming than corn at the 5-leaf stage, which re-grew a week later. Such differences are
likely a result of the physical position of the growing point at the time of flaming (Ascard 1995;
Hansson and Ascard 2002; Knezevic and Ulloa 2007; Ulloa et al. 2010a). The growing point in
grass species during early growth stages is typically below the soil surface and, thus, would be
protected from the flame. In contrast, the growing point in broadleaf species is usually above the
ground and, thus, would be exposed to the flame.
Practical Implications. The practical implications of our findings are that flaming should be more
effective if conducted during the afternoon, particularly from 3 P.M. to 6 P.M. (calculated
arbitrarily on the basis of a standard day of June 15, 2009, Table 4). Flaming during afternoon
might result in better weed control; however, crops would also experience more injury at this time.
We believe that adjusting the angles of torches and positioning the flames below the crop canopy
would result in lower crop injury and yield reduction under field conditions. An experiment should
be conducted to test such a hypothesis. Further experiments are required to determine whether the
improved flaming efficacy observed during the afternoon in this early growth study occur to the
same degree under field conditions and whether these effects continue through to harvest impacting
crop yield. More research also needs to be done with flaming of other important weeds and crops to
determine the biologically effective propane dose with respect to various times of day. Information
from such research would enhance flaming recommendations in integrated weed management plans
for both organic and conventional crop production systems.
Sources of Materials
1
Vapor phase VT 2-23 C burner, http://www.flameengineering.com/Weed_Dragon.html. Flame
Engineering, Inc., LaCrosse, KS 67548.
2
R statistical software, R Foundation for Statistical Computing, Vienna, Austria. URL:
http://www.R-project.org.
Acknowledgements
We would like to acknowledge the financial contributions of the Propane Education and Research
Council (PERC) and the Nebraska Propane Association. We are also grateful for the help provided
by Brian Neilson, Robert Leskovsek, and Strahinja Stepanovic.
Literature Cited
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