southern Spain, which contains the highest known concentration of greenhouses
within the EU community; an area of 28,576 ha’s of protected crops, grown
mostly under plastic structures along a narrow coastal strip in the Province of
Almeria.
Pest control in greenhouse crops in northern Europe has shown an important
evolution within the past 30 years through the replacement of chemical control by
biological control, mainly due to pest resistance to insecticides (van Lenteren 2007).
The same has recently been reported in greenhouse crops in Spain (van der Blom
2010). The causes have been the same: excessive use of chemical control (Cabello
and Cañero 1994; Cabello 1996) and pest resistance levels to insecticides (Cabello
2009), what is overlapped with, paradoxically, the low technical efficiencies of
pesticide application systems (Aguera et al. 1998; Garzón et al. 2000; Cabello et al.
2001). In contrast to the northern Europe, the implementation of biological control in
Almeria was achieved in such a short time that some journals named it the ‘green
revolution of Almeria.’ In the past, the pressure of pests in Almeria was very high,
due to the high concentration of greenhouses, with overlapping of crops all year
round, and the lack of hermetic structures, that together with the polyphagy of some
pests promoted the high development of their populations (Cabello and Cañero
1994). Since many chemical active ingredients had been already banished in the EU,
the high number of applications of the remaining legal ones gave the best scenario for
development of resistances of pests, which were not controlled anymore, then promoting the use of illegal products in some cases, as an erroneously desperate
alternative. The establishment of biological control completely reversed the situation, turning the province into a Mediterranean and worldwide reference about the
successful application of IPM strategies.
Over the 2012 season, biological control has been applied to 70 % of the
greenhouse crops of Almeria but the transition has not been accomplished at the
same time in all vegetable crops. Sweet peppers were the first where biocontrol
was fully established, changing from 2 % under IPM in 2006/2007 to more than
73 % in 2008. In the following years, almost 100 % of this crop was already
produced under biocontrol, which means about 8,400 ha. In contrast, the shift was
achieved a few years later in tomatoes, which is the other major crop of the
province, probably because the chemical control was offering a reasonable pest
solution in this crop. But once the growers realized that biological control was
cheaper and offered a better control of the major pests, as well as a control of the
exotic recently arrived pest T. absoluta (Lep.: Gelechiidae) (Fig. 4.2), the change
was also fulfilled in only 2 years. By 2011, 50 % of the tomato crop had followed
suit, and currently almost the total surface, approx. 10,200 ha, are protected by
biological control systems.
102
E. Vila and T. Cabello
within the EU community; an area of 28,576 ha’s of protected crops, grown
mostly under plastic structures along a narrow coastal strip in the Province of
Almeria.
Pest control in greenhouse crops in northern Europe has shown an important
evolution within the past 30 years through the replacement of chemical control by
biological control, mainly due to pest resistance to insecticides (van Lenteren 2007).
The same has recently been reported in greenhouse crops in Spain (van der Blom
2010). The causes have been the same: excessive use of chemical control (Cabello
and Cañero 1994; Cabello 1996) and pest resistance levels to insecticides (Cabello
2009), what is overlapped with, paradoxically, the low technical efficiencies of
pesticide application systems (Aguera et al. 1998; Garzón et al. 2000; Cabello et al.
2001). In contrast to the northern Europe, the implementation of biological control in
Almeria was achieved in such a short time that some journals named it the ‘green
revolution of Almeria.’ In the past, the pressure of pests in Almeria was very high,
due to the high concentration of greenhouses, with overlapping of crops all year
round, and the lack of hermetic structures, that together with the polyphagy of some
pests promoted the high development of their populations (Cabello and Cañero
1994). Since many chemical active ingredients had been already banished in the EU,
the high number of applications of the remaining legal ones gave the best scenario for
development of resistances of pests, which were not controlled anymore, then promoting the use of illegal products in some cases, as an erroneously desperate
alternative. The establishment of biological control completely reversed the situation, turning the province into a Mediterranean and worldwide reference about the
successful application of IPM strategies.
Over the 2012 season, biological control has been applied to 70 % of the
greenhouse crops of Almeria but the transition has not been accomplished at the
same time in all vegetable crops. Sweet peppers were the first where biocontrol
was fully established, changing from 2 % under IPM in 2006/2007 to more than
73 % in 2008. In the following years, almost 100 % of this crop was already
produced under biocontrol, which means about 8,400 ha. In contrast, the shift was
achieved a few years later in tomatoes, which is the other major crop of the
province, probably because the chemical control was offering a reasonable pest
solution in this crop. But once the growers realized that biological control was
cheaper and offered a better control of the major pests, as well as a control of the
exotic recently arrived pest T. absoluta (Lep.: Gelechiidae) (Fig. 4.2), the change
was also fulfilled in only 2 years. By 2011, 50 % of the tomato crop had followed
suit, and currently almost the total surface, approx. 10,200 ha, are protected by
biological control systems.
102
E. Vila and T. Cabello