In the not-too-distant past, those who bought organic produce represented one to two per cent of consumers. While this percentage has increased, organic produce still only represents a small share of the total market - so perhaps more relevant in the context of commercial production is the issue of low- or no-residue produce. Dutch growers now estimate that low- or no-residue (rather than truly “organic”) produce has risen to 20-25 per cent of the market, and they are struggling to satisfy demand. As a result, prices are being pushed up and there are concerns that if they go too high, demand will start to fall away.
One of the problems in this sector, according to Jacco Vooijs, manager (food safety) at Dutch grower co-operative FresQ, is that national interpretation of European law for organic production varies. For example, in the Netherlands, the fact that organic production must be in soil and that grow-bags are not acceptable is discouraging many growers and creating a constraint on potential growth. “Such differences are really a major issue,” says Vooijs. “We need to have a unified European ruling on these, as on other matters.”
There is, of course, increasing pressure from major retailers, especially in northern Europe, to reduce pesticide residues to zero. As the list of approved pesticide products becomes ever more limited in Europe, many retailers are becoming more stringent in their production protocols and encouraging greater use of biological controls. Such requirements are likely to apply to a number of countries, including the UK, Germany and Denmark, and suppliers will all be subjected to new demands. Problems with illegal residues in sweet peppers from Spain in 2006 highlighted the issue further, and growers there are aware of the need to meet the standards required, simply to maintain their markets.
“In the Netherlands, we would like to see harmonisation of national registration requirements of crop protection products in general across Europe, to give us a level playing field for production,” Vooijs says. Acknowledging that different countries have different product requirements, he suggests: “They could at least be harmonised on a regional basis. Speeding up this process would be helpful.”
FresQ growers produce tomatoes, peppers and aubergines. In tomatoes in particular, the extension of the production season through the use of artificial light in greenhouses has brought its own pest pressures. Planting used to be in December or January and predators were introduced in February, to be well established before the arrival of white fly in April or May. The season now starts in September and small white fly populations carried over from the end of the previous season can build up quickly in the warm, light conditions. Particular attention needs to be paid to boost predator and parasite populations at this stage, for example using Macrolophus and Diglyphus. The use of beneficial insects as part of an integrated pest management (IPM) programme can help to achieve control consistent with the demands placed on growers by supermarket customers. In case of population imbalances, growers like to have selective chemicals, safe to beneficials, available to help knock down the pest at these times, but say that there are not enough available.
“Oberon (spiromesifen) is ideal for use alongside the biological predators. It is effective against strains of white fly that are resistant to other treatments and also provides control of spider mite,” says Vooijs. “A further much-used option, Applaud (buprofezin), can be used with Encarsia formosa for control of white fly and also has additional activity on scale, mealy bug and leaf hopper pests.
“There are organic fungi like BotaniGard and Mycotal, which provide some control by infecting white fly larvae and aphids and are safe for predators, but growers must be mindful of the timing of use of other available control products such as pyridaben, abamectin or methomyl carbamate, because they knock out the biological predators in the crop.
“Growers always prefer to use biological predators if they can,” he adds. “They don’t like chemicals for a number of reasons: the time involved in application, the possible effects on the health of workers and the potential for residues on the product, but sometimes their use cannot be avoided. Something we are concerned about is that the reduction in the number of approved chemicals available means that there are not enough in some cases to allow rotation for resistance strategies.”
Fungal diseases such as botrytis and fusarium also present a challenge, particularly in organic crops. In a wet year like 2007, growers can find that there are few solutions available to them.
Integrated pest management
Fortunately, however, low- or no-residue production can now be achieved in a variety of crop situations, and development work in this area continues to expand the possibilities open to growers. Biological Crop Protection (BCP), sister company to Certis Europe, has made considerable progress in developing integrated pest control programmes for protected vegetables, soft fruit and ornamentals on a crop-by-crop, country-by-country basis, depending on local situations and local registrations. Programmes are already available for tomatoes and peppers in most western European countries.
Tomatoes
A frequent component of the programmes for protected tomatoes is to start cleaning before planting the crop, to prevent both disease transfer and insect carry-over, using a disinfectant such as Jet 5. Many growers may also use a chemical such as abamectin to be sure of knocking out any remaining insect pests. Beneficial insects are introduced after planting to prevent infestation, as far as possible.
In France, these might include Encarsia formosa, Encarsia with Eretmocerus, Eretmocerus eremicus andMacrolophus caliginosus for white fly, along with Aphidius colemani and Aphidoletes aphidimyza for aphids. Monitoring is essential so that curative measures can be taken. In the case of high pest pressures, corrective measures may be required, using, where possible, biopesticides compatible with the beneficial insects. Again in France, Supreme (acetamiprid), Applaud (buprofezin) and Nissorun (hexythiazox) could be products of choice. As Jacco Vooijs said, availability of such products varies from country to country. For example, in the UK, the armoury of IPM-compatible pesticides includes Eradicoat T (maltodextrin), Oberon (spiromesifen), Applaud, against the various insect pests, and Frupica (mepanipyrim), as well as Repulse (chlorothalonil) against diseases. The ERII formulation of maltodextrin is available in the Netherlands, along with other selective insecticides such as Applaud, Nissorun, Floramite, Turex and BotaniGard. Clean-up solutions at the end of the crop also vary from Oberon in the UK and the Netherlands to Supreme in France, which will also be available next year in the Netherlands under the name Gazelle.
Spanish tomato grower Juan Gonzalez Vargas of Motril, Granada, says major changes have been necessary in his approach to production and business. “Everything is changing - the pesticides available, market regulations, official European guidelines, fruit prices, production costs,” he says. “I have had to adjust my business to all these changes. However, using beneficials means that I avoid residue problems and, in addition, I can control some pests that were never controlled before. Products like Turex are bio-products, compatible with biological controls, to control caterpillars in my crop.” He adds: “It’s a new way of producing, and we have to change our mindset to cope.”
Peppers
Monitoring for insect pests is important before planting of peppers, and sticky traps are used for this purpose. A similar process to that in tomatoes is followed with beneficial insects backed up by monitoring, further introductions of predators, biological insecticides and the use of pesticides only where absolutely necessary. IPM programmes have been developed specific to the UK, France, Belgium, the Netherlands and Spain, with excellent results. Trial work in a commercial situation has demonstrated a 38 per cent increase on returns for growers using IPM (see box on pepper trials).
Soft fruit
Some of the latest developments are in programmes for soft fruit in the UK, Spain and the Netherlands, and BCP is also doing more work in the challenging area of fungal disease control. In its work with growers, the company finds that disease problems are reduced where pest management and cultural controls are good.
Strawberries
As the area of protected cropping in UK strawberry production has grown, the use of biological controls has increased, and they now provide effective control of major pests such as thrips and spider mite. However, as with tomatoes in the Netherlands, glasshouse whitefly has become a more problematic pest and, in some cases, reached unmanageable infestation levels where even chemicals do not provide effective control. In one such case, BCP developed an IPM programme including Encarsia, Phytoseuilus and predatory mites
in combination with selective insecticides and fungicides, and
results were compared against a conventional programme.
While the costs of integrated control were higher than conventional, they were more than compensated by a dramatic improvement in pest control and higher returns. Over a three-year period, crop protection costs declined by 11 per cent, as the adoption of IPM throughout the nursery led to fewer pest outbreaks and reduced need for emergency treatment. In practice, the more stable ecosystem created also allowed the grower more time to manage the crop, as well as increased yield and crop quality. The reduction
in the number of insecticide treatments and the use of more friendly pesticides was particularly pleasing to crop workers and also responds to the demands of supermarket protocols.
The way forward
Low- or no-residue production is becoming increasingly possible, and companies like Certis and BCP are making excellent progress for the benefit of growers of a variety of protected vegetables, ornamentals
and soft fruit across Europe. Growers should take advice on their own specific situation, based on what is happening in the crop and local registrations; but there are a growing number of possible solutions to assist them to meet market requirements and, in some cases, potentially increase profits too.
PEPPERS ON TRIAL
A trials programme conducted in the Almería region by Biological Crop Protection and marketing organisation The Greenery, plus its co-operatives, demonstrates clear benefits offered to growers by integrated pest management (IPM). It set out to compare a conventional chemical-based control programme for peppers with a new IPM strategy, combining several biological controls with chemical products selected for their compatibility with beneficial insects.
Ten plots were used for the trials: three using conventional chemical-based controls (18,500sqm) and seven using IPM programmes (42,500sqm). All crops were planted during June and July 2005.
In these trials the IPM programme provided effective pest control using Amblyseius cucumeris, Orius and Nesidiocoris, offering a major advantage of excluding pesticides with high potential residue risks. Residues were in fact reduced well below maximum limits, thereby allowing growers access to the markets provided by the north European supermarkets. This benefit alone offers a major impetus for the adoption of IPM in Almería.
However, this was not the only gain from using IPM. Yields ranged from 5.3 to 5.8kg/sqm (average 5.5kg/sqm) in the plots using conventional controls, and from 5.8 to 6.6kg/sqm (average 6.19kg/sqm) in the IPM plots. In addition to producing extra yield, the crop was also of higher quality, due to less stress from chemical-based conventional treatments. As a result, a price premium was achieved, increasing returns by 17 per cent from £2.56 (conventional) to £3/sqm (IPM).
The total cost of pest control on the IPM plots (€0.68/sqm) is calculated including the costs of beneficial insects (45 per cent of total cost) plus the low impact insecticides and fungicides (55 per cent of total cost). The results showed that grower input costs were reduced by 30 per cent under the IPM programme. Labour costs were not calculated in the project but it is clear that, with fewer treatments needed, labour requirements are lower for IPM than for conventional treatments, so these costs will also be reduced.
The combination of reduced costs for the IPM programme and higher returns for the crop created a substantial overall improvement in grower margins over input costs of 38 per cent, as well as meeting the demands of the northern European supermarkets for reduced residues in the fruit.
IPM FOR UK SOFT FRUIT
• Oberon, an effective whitefly clean up, was applied under an off-label approval pre-flowering
• Predatory mites, one to two weeks after Oberon
- Amblyseius cucumeris
- Amblyseius californicus
- Hypoaspis miles
• Phytoseiulus persimilis in hot spots
• Encarsia Formosa from mid-April
• Eradicoat in pest hot spots
• Frupica and Jet 5
Results generated jointly by Biological Crop Protection and strawberry growing manager Jon Marcar showed the IPM programme provided effective pest control with an eight per cent increase in Class I fruit, due to a reduction in the fruit damage caused by thrips, and a six per cent increase in yield compared to the conventional programme. Even though pest control costs, including necessary labour, were higher, overall returns were 18 per cent higher from the IPM programme and the number of insecticide treatments was reduced from 10 to four. The table below quantifies the benefit of IPM to the grower, comparing two adjacent blocks in spring 2005.
Ongoing work
Further work in this area has continued and new trials have now shown that Encarsia can provide effective control of whitefly at a reduced rate of one per sqm weekly, which makes it even more cost effective. Where Encarsia was introduced on this basis from mid-April to the end of May, the pest was effectively controlled for the remainder of the crop. Pymetrozine can also play a role in a cost-effective IPM programme.
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