3.1. Establishment of Homogeneous Crop Areas through Growers Associations
The data shown reflect the results of the plan for subsidies for the control of insect vectors of viruses in protected horticultural crops in the province of Almería over the 2007/08, 2008/09, 2009/10 and 2010/11 seasons. A total of 77 grower associations from three areas of the province took part. The municipality of El Ejido accounted for 32 enterprises (41.56%) and 42.57% of the greenhouse crop area.
Thirty-five of the 77 entities that benefited from the subsidies were producer associations (P.A.), 24 were Agricultural Processing Companies (S.A.T.) and 17 were Andalusian Cooperative Societies (A.C.S.). It should be mentioned that 19 of the 35 producer associations were set up around suppliers who committed themselves fully to the marketing of BCOs to offset the fall in sales of phytosanitary products and offer a full range of products for pest control. This fact is significant in that the priority of all their PCAs shifted from recommending insecticides and acaricides to promoting sales of BCOs. This avoided, to a great degree, the danger that some PCAs affiliated to agricultural product suppliers would have a conflict of interest in recommending biological control methods. While these suppliers affiliated PCAs provide pest monitoring and consulting services for free, their employers stay in business by selling pest control products.
3.4. Control and Monitoring
The Department of Agriculture and Fisheries for the Regional Government of Andalusia set up a field-sampling plan that would involve 100% of entities benefiting from subsidies, with samples being taken from at least 10% of the surface area for which the subsidies were awarded. Visits to the farms were carried out by technicians from the administration in the compulsory presence of the grower and the PCA. The farm’s technical characteristics were checked, as were the data annotated in the compulsory logbook [17
], to ascertain that the control plan was being correctly followed. All PCAs were obliged to register their intervention instructions (release of BCOs, phytosanitary treatments, etc.).
This procedure prevented growers with independent PCAs from receiving more frequent visits and written status reports than growers who used supplier-affiliated PCAs. It also prevented some growers from making use of more than one PCA in the hope of getting better technical advice, as has happened in California in the cultivation of cotton where 50% of farmers have 2 or more PCAs [18
]. Though in California the type of PCA appears to play an important role, this is not the case in Almería.
The in situ field monitoring was complemented with data collection via the TRIANA software program, in which each PCA had to note the data from the field logbook over 4 consecutive winter seasons.
These two control mechanisms most likely contributed greatly to the success of the implementation of biocontrol, suitable use of BCOs was ensured to control pests, while at the same time, phytosanitary applications were kept to a minimum, and always in situations which were in no way to the detriment of the BCOs. The monitoring also allowed the authorities to determine an overall decrease in the presence and incidence of the main pests for horticultural crops: whitefly, thrips, aphids (all of which are insect vectors of viruses) and caterpillars. In pepper crops, this drop in incidence was particularly noteworthy. In 2007/08, thrips were found to be present in over 30% of plants, with 10% affected by TSWV in some areas and up to 9% of fruit affected [19
]. However, during just three crop seasons, these values fell to 17.3%, 0.9% and 1.1%, respectively. The authors of [20
] found that in field and row production, the annual nature of the crops, their greater level of seasonal disturbance, and the highly dispersive nature of many of the associated pests, are important barriers for the establishment and impact of introduced natural enemies. Nevertheless, here it has been shown that the same does not hold true for greenhouse crops. Despite the brevity of the crop cycles, the BCOs not only survived but their populations increased exponentially and held the main pests in check.
The supervision procedures also provided evidence on other crops, namely watermelon and melon, especially in the second crop cycle, showing a decrease in the number of releases and in the doses of BCO applications, possibly due to a fall in the amount of aid from the 2009/10 season onwards, among other reasons. The efficiency of the system implemented allowed rapid action to be taken, setting minimum compulsory doses for the control of insect vectors of viruses from September 2010 [21
]. Correct application of these minimum doses was a condition sine qua non for growers to be awarded subsidies (Table 3
However, in certain exceptional circumstances, lower doses were allowed on qualified technical advice. It should also be pointed out that certain growers opted for placing among their plants pruned branches from other greenhouses into which BCOs had already been released, thus establishing high populations of these beneficial insects in the new crops. “Interplanting” is a technique which fosters the presence of BCOs, transferring them from autumn-cycle to spring-cycle crops.
The release of the BCOs until reaching the dose indicated in Table 3
was generally carried out in at least two moments. For the control of whiteflies, the most used OCBs were the predatory bug Nesidiocoris tenuis
(Hemiptera: Miridae) and the predatory mite Amblyseius swirskii
(Acari: Phytoseiidae), which can be used alone or in combination depending on the crop, as shown in Table 3
. For the control of thrips, in addition to the two OCBs indicated above, the predatory bug Orius laevigatus
(Hemiptera: Anthocoridae) and the predatory mite Amblyseius cucumeris
(Acari: Phytoseiidae), were used. The most common combinations for trips control according to crops are shown in Table 3
. The predatory bugs were released on the plant canopy or by using an application box hung on the plant and the mites were released mainly in slow release hanging sachets. The control of aphids by the parasitic wasp Aphidius colemani
(Hymenoptera: Aphidiinae) was carried out by using banker plant prior to the detection of aphids in the crop, based on introducing cereal aphids into a greenhouse on cereal plants and A. colemani
Despite these and other actions intended to minimize abundant releases of BCOs, the demand for products was very high, and as a result, the number of enterprises involved in the commercialization of BCOs increased rapidly, reaching a plateau in 2011/12.
3.5. Production Capacity and Price of BCOs
At present, over 70% of the companies marketing the main BCO products registered in Spain for horticultural crops (A. swirskii
, A. colemani
; O. laevigatus
, N. tenuis
and A. cucumeris
) are in Almería (16 of 23), and the 118 products they offer represent 88% of the total available on the market. A further indication of the importance of Almería in this market is the fact that 9 of the 10 companies with the highest number of registered products have their Spanish headquarters in this province (Table 4
The rapid growth of enterprises in this market allowed a downward trend in costs to the grower due to the greater competition for distribution to a limited crop surface area. However, the adjustment in the doses of BCO releases constituted an additional factor in the reduction of costs. This was made possible by the decrease and gradual elimination of phytosanitary residues in the greenhouses, the greater know-how acquired, the perfection of techniques applied and the fall in incidence of crop pests with regard to 2007/08. To illustrate this final factor, in 2007/08, it was necessary to release 4 Orius laviegatus/m2 to control Frankliniella occidentalis in pepper crops, whereas in 2010/11 many greenhouses were able to achieve this aim with only 1.7 Orius/m2.
According to publications of the Research Institute of the Cajamar Foundation [22
] from biological control’s arrival on the scene in 2007/08 to the 2012/13 season, pest control cost (chemical control + biological control) fell by 32.16%.
Companies marketing BCOs products registered in Spain in 2022. Source: MAPA, [23
Companies marketing BCOs products registered in Spain in 2022. Source: MAPA, [23
|Enterprise||No. BCOs Products||Province/Country|
|Agrinature Producciones Agrícolas, S.L.||1||1||1||1||Almería (Spain)|
|Agrobio, S.L.||1||2||2||1||1||Almería (Spain)|
|Agrocontrol 2007, S.L.||1||1||1||1||Almería (Spain)|
|Agroquímicos Los Triviños, S.L||1||Murcia (Spain)|
|Bgreen Biological System, S.L.||1||1||1||1||1||Almería (Spain)|
|BICHELOS, Control Biológico S.L.||1||1||1||Valencia (Spain)|
|Biobest Sistemas Biológicos, S.L.||5||4||3||1||4||Almería (Spain)|
|Biocolor Iberia, S.L.||1||1||1||1||Almería (Spain)|
|Biocontrol Del Mediterráneo, S.L.||1||Alicante (Spain)|
|Bioline Agrosciences Limited Iberia||1||3||1||1||1||Almería (Spain)|
|Bioplanet Ibérica, S.L.||5||4||2||2||3||Almería (Spain)|
|Biosur Productos Agrícolas, S.L.U.||3||2||1||1||2||Almería (Spain)|
|Certis Europe, B.V.||1||1||1||1||2||Alicante (Spain)|
|Entonova, S.L.||1||1||1||Almería (Spain)|
|Insectaria, S.L.||1||1||La Rioja (Spain)|
|Insectos Med, S.L.||1||1||1||Almería (Spain)|
|Koppert Biological Systems, S.L.||4||3||2||2||3||Almería (Spain)|
|Mip System Agro, S.L.||4||2||2||2||3||Almería (Spain)|
|Plant-E Productos Naturales S.L||1||1||Navarra (Spain)|
|Provi Agricola, S.L.||1||1||1||Almería (Spain)|
|Saniveg, S.L.||1||1||2||1||1||Almería (Spain)|
|Surinver El Grupo||1||Alicante (Spain)|
|Verde Ibérica, S.C.A.||1||1||1||Almería (Spain)|
|Total||32||29||28||24||21||Almería (Spain)|Table 5
provides an overview of the annual production costs of a typical plastic greenhouse small holding expressed in euros/ha. Applying these data to the current total greenhouse surface area of 29,500 hectares, the growers’ savings due to the introduction of biological pest control over the period in question would be over 43 million euros.
In 2006/07, expenditure on pest and pathogen control was 100% on chemical methods, and after that date, expenditure is divided between chemical and biological techniques. Pesticide control methods, aimed principally at pathogen control (especially fungi), fluctuate slightly from 2007/08 onwards, whereas the cost of biological control methods fell steadily over the same period, thus reducing growers’ expenditure on pest control.
3.6. Maintaining the System over a Minimum Number of Crop Seasons to Ensure Its Stable Implementation
Public subsidies were originally planned to be maintained over 4 agricultural years and to cover 50% of the purchase costs of BCOs. However, this plan fell through with the advent of the international recession which hit Spain in 2008 and the subsequent banking crisis in 2010. Public funds were no longer available to uphold the plan, and as a result, subsidies dropped in the 2009/10 and 2010/11 crop seasons to cover less than 25% of BCO purchases. This entailed the risk that some associations might opt out of the control plans and that other might not become involved. However, the other line of subsidies aimed at IPGs was maintained over the planned 5-year program, though in this case, the amounts involved were considerably lower.
outlines the public subsidies paid for the biological control of protected horticultural crops in the province of Almería. A total of 31.5 million euros was destined to IPGs and to the purchase of BCOs over 5 crop seasons. Between 2007/08 and 2011/12 campaigns, the average annual subsidy per hectare for biological control was 450.41 €, 89.4% was dedicated for purchase of OCBs and 10.6% for contracting PCAs.
There is a clear drop in demand for subsidies for the purchase of BCOs from 2009/10 onwards. It would be a mistake to attribute this to a loss of interest in biological control. While it is true that certain growers’ associations forewent subsidies due to the fact that the aid received did not offset expenses in administrative tasks, they did in fact continue to employ biological control organisms for pest control.
It is quite remarkable that the first two years proved sufficient to convince those growers who undertook biological control of the worth of this method, as Table 7
illustrates. It shows the percentage of greenhouse crop area in Almería in which biological control methods were implemented over 8 agricultural seasons between 2005 and 2013, detailing the number of hectares that received subsidies for the purchase of BCOs (against insect vectors) on the one hand, and for contracting PCAs on the other (IPGs).
clearly reflects the exponential increase in biological control methods immediately after the food safety alert, coinciding with the offer of public aid. The initial sharp increase in crop area treated with these methods was followed by less marked increments in subsequent seasons, but with a steady upward trend.
In 2007/08, almost 90% of the crop area that was treated with biological control methods came under the umbrella of the aid plan for the purchase of BCOs, which acted as a driver to change in pest control systems. Two years later, over 40% of the crop surface under biological control received no subsidies, and this period coincided with the fall in the subsidies offered. Unlike the subsidies for the purchase of BCOs, those destined for IPGs fell less sharply. In fact, this aid remained constant due to the 5-year commitment to the plan demanded of the growers at the outset.
BCOs can currently be considered the “conventional” pest control method in Almería. In the last eight years (2013–14 to 2020–21), the average area dedicated to biological control has been 25,472 ± 1262 hectares although with slight interannual modifications. Their efficiency in keeping pests in check and their relatively low cost (considerably less than insecticides and acaricides) have won over growers, who have embraced this method irrespective of the final market destination of their produce and of the quality certifications they use.
Two factors have contributed to solving the occasional problems that have arisen in connection with biological control in greenhouses in Almería: on the one hand, the mean size of farms in Almería means that growers are well aware of the phytosanitary conditions of their crops, and on the other, social, technical and business factors have combined to maintain a high level of interest and commitment to this pest control method. As a result, the planning and management of BCOs in IPM programs of greenhouse horticultural crops have become universal standards for the whole province. This uniformity within the greenhouses of the province constitutes a barrier to the arrival of major populations of new pests, and therefore provides the system with the stability which helps to maintain it.