© Benaki Phytopathological Institute
Marinan-Arroyuelo
et al.
66
to oxyfluorfen. The time required for hand
weeding (Table 2) was significantly shorter
in treatments that included pendimethalin
and this is explained by the residual activity
of the herbicid
e
.
The best benefit/cost ratio (69.1) in this
experiment was obtained with post-emer-
gence oxyfluorfen and not with pre-emer-
gence pendimethalin due to the pres-
ence of
Polygonum convolulus
. Despite
that, a quite favourable ratio was also ob-
tained with pendimethalin (47.1) as well as
Table 1.
Results from the processing tomato field trial (Greece, 2010).
Treatments
Yield
(Kg/ha)*
Labour for
hand
weeding
(hr/ha)*
Yield
value
(€/ha)
1
Weed
control
costs
(€/ha)
2
Benefit/
Cost
ratio
(€/€)**
Labour
return value
(€/hr)***
Untreated control
22580 b
-
1423
-
na
3 Hand weedings (3 hw)
54193 a
190 a
3414
950
2.1
10.5
Pendimethalin
50280 a
-
3168
101
17.3
Pendimethalin + metribuzin + 2 hw 57207 a
26 c
3604
313
7.0
16.8
S-metolachlor
25527 b
1608
62
3.0
S-metolachlor + metribuzin + 2 hw 57853 a
91 b
3645
599
3.7
22.4
1
The farmer’s price in Greece for the 2010 period was 63 €/ton (based on industry sources).
2
Labour cost for hand weeding (payment 5 €/hr, based on local sources) + Value of herbicide (Stomp 17 €/L,
Sencor 65 €/Kg, Dual 24,6 €/L) + Cost of application (50 €/ha for Stomp incorporated, 30 €/ha for Dual or Sencor
surface-applied).
* Means of three replicates. Values within a column followed by the same letters are not statistically different at
P=0.05.
** Benefit/Cost ratio for a treatment (€/€) = (Yield value of the treatment – Yield value of untreated control)/Weed
control costs of the treatment.
*** Labour return value for a treatment (€/hr)= (Yield value of the treatment with hand weeding – Yield value of
the treatment without hand weeding)/Labour for hand weeding.
Table 2.
Results from the seeded onion trial (Italy, 2011).
Treatments
Marketable
yield
(Kg/ha)*
Labour
for hand
weeding
(hr/ha)*
Yield
value
(€/ha)
1
Weed con-
trol costs
(€/ha)
2
Benefit/
Cost
ratio
(€/€)**
Labour
return value
(€/hr)***
Untreated control
4292 d
-
773
0
na
2 Hand weedings (2 hw)
32268 bc
1095 a
5808 12045
0.4
4.6
Pendimethalin pre
21048 c
3789
64
47.1
Pendimethalin pre + 2 hw 41679 b
476 b
7502
5300
1.3
7.8
Oxyfluorfen post
38851 b
6993
90
69.1
Oxyfluorfen post + 2 hw 48988 b
1369 a
8818 15149
0.5
1.3
Pendimethalin pre
+ oxyfluorfen post
43089 b
7756
154
45.3
Pendimethalin pre
+ oxyfluorfen post + 2 hw 59542 a
611 b 10718 6875
1.4
0.4
1
Actual farmer’s price 0.18 €/kg (for 50-80 mm bulbs only) (based on market sources).
2
Labour cost for hand weeding (payment in Italy 11 €/hr, based on local sources) + Herbicide value (Stomp Aqua
455 CS 17 €/L, Goal 48 CS 80 €/L) + Cost of application (30 €/ha surface application of both herbicides).
* Means of three replicates. Values within a column followed by the same letters are not statistically different at
P=0.05.
** Benefit/Cost ratio for a treatment (€/€) = (Yield value of the treatment – Yield value of untreated control)/Weed
control costs of the treatment.
*** Labour return value for a treatment (€/hr)= (Yield value of the treatment with hand weeding – Yield value of
the treatment without hand weeding)/Labour for hand weeding.
