© Benaki Phytopathological Institute
1
Technical market development, BASF Espanola SA
2
Field Trial Services, BASF Italia SA
3 Field Trial Services, BASF Espanola SA
4
Field Trial Services, BASF Hellas SA
5
Product Development, BASF Hellas SA, Athens,
Greece
6
Currently Editorial Committee of AgroTypos SA,
former Director of Weed Science Department at the
Benaki Phytopathological Institute, Greece
* Corresponding author:
Hellenic Plant Protection Journal
7
:
61-72, 2014
Weed control benefit to cost ratio and labour return value
in crops of southern European countries with the use of
herbicide pendimethalin
E. Marinan-Arroyuelo
1
, A. Marchi
2
, F. Marchal-Rubio
3
, C. Bozoglou
4
, D. Servis
5
and C.N. Giannopolitis
6*
Summary
Specially designed field trials were conducted in transplanted processing tomatoes, di-
rect-seeded onions (dry bulb production), cotton and broccoli (fresh vegetable market) considered as
four of the core crops determining the importance of using pendimethalin for weed control in south-
ern European countries. Based on yield data and actual farmer’s prices for costs and products, the ex-
pected weed control benefit/cost ratio was determined when pendimethalin, some alternative herbi-
cides, hand weeding or a combination was used. In most cases pendimethalin, being sufficiently ef-
fective as a single treatment, provided the most favourable benefit/cost ratio, which was by far bet-
ter than the ratio obtained with hand weeding. Evidence is also provided that alternative weed con-
trol methods, like inter-row cultivations and on the row polyethelene mulching, which were not used
in this study, are by no means able to provide a ratio equivalent to that of pendimethalin. The labour
return value analysis further revealed that hand weeding, which as a weed control method is not ec-
onomically justified by itself in any case, can become justifiable as a supplementary measure follow-
ing a pendimethalin application in many cases. These results clearly show that pendimethalin (or any
herbicide acting similarly) has the potential to provide a favourable benefit/cost ratio for the control
of weeds in crops, like the ones examined in this study, that are associated with an increasing demand
for the lowest production costs.
Additional keywords
: broccoli, cotton, onion, processing tomato, weed control costs, weed control profits
Introduction
Pre-emergence herbicides, having a resid-
ual activity in soil, can often offer satisfac-
tory weed control applied as a single treat-
ment in situations where emergence of
weeds continues for a longer period. Avail-
ability of such herbicides, however, has be-
come limited in recent years, because of the
withdrawal of many older active ingredients
during the re-registration process in the EU
according to Directive 91/414 (eg. EU, 2008).
European farmers, thus, have turned more
to multiple applications of post-emergence
herbicides.
Increased selection pressure associated
with repeated multiple applications of post-
emergence herbicides has already led to
weed species becoming resistant to many
of these herbicides including the ACCase-in-
hibitors (Bravin
et al
., 2001; Papapanagiotou
et al
., 2012), the ALS-inhibitors (Scarabel
et
al
., 2004; Kaloumenos and Eleftherohorinos,
2008), glyphosate (Collavo and Sattin, 2012;
Nol
et al.
, 2012) and others. Multiple applica-
tions are also very likely to increase the cost
of weed control but clear evidence with spe-
cific crops is not available in the literature up
to now.
In this study specially designed field trials
were conducted that allowed determination
