Profitability of using warning system for foliar disease of wheat in the Grand-Duchy of Luxembourg

Although small grain cereals (i.e. winter wheat) are routinely protected with
two or three foliar treatments in the Grand-Duchy of Luxembourg (GDL),
environmental concerns and changes in the cost-benefit ratio are likely to
increase the demand for more accurate identification of spraying needs. A
Vol. 103 (Supplement 2), No. 6, 2013 S2.39
warning system assessing in real time the risk of progression of fungal
diseases on winter wheat (Triticum aestivum L.) was tested in the GDL over
the 2009-2012 period in four-replicated field experiments located in three
representative villages of the different agro-climatological zones. The
fungicide treatments recommended by the warning system during this period
have ensured economic profitability equivalent to or even better than double
and triple treatments. In 2010 and 2011, weather conditions impeded fungal
infections of wheat and no warning was issued, reducing fungicide use. The
study also highlighted that multiple fungicide applications were not better than
a single application. In 2009 and 2012, although the weather conditions were
very favourable for fungal wheat diseases, the single recommended fungicide
application resulted in an additional yield of 30% compared to untreated plots.
This study shows the importance of the positioning of fungicide treatment in
such a warning system and in strategies aiming at reducing the spread
fungicide molecules in the environment.