© Benaki Phytopathological Institute
Weed control benefit to cost ratio with pendimethalin
71
herbicides currently available to growers
and they have to rely exclusively on few pre-
emergence herbicides.
Conclusions
Field trials in this study with diverse annu-
al crops (processing tomato, dry bulb on-
ion, cotton and broccoli) demonstrated that
pendimethalin, a residual herbicide with a
broad weed spectrum, can in many cases be
sufficiently effective as a single weed con-
trol treatment to provide maximal yield and
best weed control benefit/cost ratio. Other
alternatives that prevented yield loss, espe-
cially hand weeding, provided much lower
benefit/cost ratios and cannot be regarded
as profitable by farmers.
Determination of hand weeding labour
return values further substantiated useful-
ness of the pendimethalin residual activity.
By significantly reducing the required time
of hand weeding, pendimethalin improved
considerably the labour return value. Hand
weeding thus became justifiable as a sup-
plementary measure while it was econom-
ically unjustified as a standalone method at
actual prices.
It becomes obvious from the results that
producers in Southern European countries
rely on herbicides like pendimethalin (only
few available) for succeeding a profitable
crop and remaining competitive in the mar-
ket. For some crops they have even changed
the cropping system to be able to use such
herbicides.
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