Biocontrols - Natural protection

With greater restrictions on chemical use and more investment by multinationals, biocontrols are becoming an increasingly attractive and viable option across a range of crops, Rachel Anderson reports.

Biocontrols: ADAS suggests use where disease pressure is lower so growers can save stronger fungicides for when really needed - image: ADAS
Biocontrols: ADAS suggests use where disease pressure is lower so growers can save stronger fungicides for when really needed - image: ADAS

Biocontrol has seen massive investment during the past five years by the likes of Bayer CropScience, Syngenta, Lallemand Plant Care and BASF and others looking to develop new crop-protection options.

Syngenta, for instance, recently purchased biotechnology seed maker DevGen. Last autumn, shortly after its $1bn purchase of biocontrol group Becker Underwood, BASF announced the opening of its expanded Littlehampton production site, now the largest facility for beneficial nematodes. Lallemand Plant Care has acquired three companies during the past few years - Laboratorio Farroupilha, BioForest and BrettYoung.

Growing market

Dr Roma Gwynn, director of biopesticide strategist Rationale, reveals that the biocontrols market is, in fact, growing by more than 15 per cent each year, which is a far greater rate than conventional chemicals' annual growth of three per cent. Indeed, there are far more biopesticides coming forward than traditional chemistry. "The global market for biopesticides is set to reach $3.2bn (£2.3bn) by 2017," Gwynn forecasts.

Dr Joshua Burnstone, technical officer for horticultural distribution company Fargro, succinctly describes the current situation when he says: "With increasing investment in the field from the large multinational companies and with a progressively diverse range of biopesticide solutions we may well be seeing a transition from the era of chemical control to the era of biological control."

Exactly what are Biocontrols?

Despite such rapid and continuing development, a cloud of confusion still surrounds biocontrols. Gwynn says: "There's no fixed global or EU definition but it's being debated at a global and EU level - and in Europe we do not have an official biopesticides category. It's hard because the technology is so diverse and because of the varying regulation situation globally.

"We have certain substances that are colloquially called biopesticides - including microorganisms (beneficial fungi, bacteria and viruses), semiochemicals (such as pheromones) and botanicals (plant extracts such as citronella oil) - but this group does not include natural enemies (predators)."

She also points out that products colloquially called biopesticides are still regulated in the same way as conventional plant-protection products (PPPs). "EU registration takes about five years and cost millions of pounds," she adds.

Andrew Gough, UK area manager for Lallemand Plant Care, no doubt echoes the sentiments of many people when he says this lengthy process can be frustrating. "We are fully accepting of the need to have these types of products approved via a systematic approach but it can't be done as it's currently being done - as if they are chemicals."

Mercifully, this situation may soon be eased by the fact that the EU must classify some products as being of low risk, Gwynn explains. "The EU is just about finalising this classification, which means that product registration will be much faster, and it looks likely that you will be able to market such products as being a low-risk product. This might mean that there isn't a need to define biopesticides because you can use the low-risk category as a way of defining them."

Gwynn also points out that some biocontrols are exempt from the tough registration process, namely entomopathogenic nematodes (including BASF's Nemasys range) and macro-biologicals such as beneficial insects like the commonly-used parasitic wasp Encarsia formosa.

Meanwhile, some products sit outside of the EU's legal framework. These include plant strengtheners, growth promoters and stimulants, and root symbionts. This situation has created a grey area where in some cases products are misleadingly promoted as being for crop-protection use.

Gwynn warns: "It's the real elephant in the room for growers. Some people play a dodgy game in a highly illegal framework." She emphasises that if a grower or a company is ever unsure whether or not a product is legal they can send examples to the Chemicals Regulation Directorate (CRD), which will determine the status of the product and follow up with appropriate action if necessary.

She adds that plant biostimulants also sat in this grey area but the publication at the end of March of a EU document on organic and waste-based fertilisers should now help clarify their status. It classifies plant biostimulants as fertilisers and also defines them as "a product stimulating plant nutrition processes independently of the product's nutrient content with the sole aim of improving one or more of the following characteristics of the plant - (a) nutrient use efficiency, (b) tolerance to abiotic stress and (c) crop quality traits."

Biopesticide Availability and Use

Gwynn reveals that while there are 120 biopesticides approved in the EU, in the UK there are only around 25 available. "Some of the reason for that is to do with the fact that the UK is seen as a fragmented market" she explains, adding that the UK also suffers from a phenomenon she refers to as "regulatory inertia".

"There seems to be a capacity problem with our UK regulator. It's just not able to process (new products) in a timely manner. Companies have gone bankrupt because CRD was so slow."

Fortunately, many of the products available in the UK are already being widely used by the horticulture industry. "It's interesting because there are moves to shift some of them from horticulture into broadacre crops," says Gwynn. Examples include biofungicides Prestop, Serenade ASO, Vacciplant and AQ10, bioherbicide Barrier H and bioinsecticide Eradicoat.

She adds: "There's a bit of a lag but I think we will see an increase as a result of SCEPTRE (Sustainable Crop & Environment Protection - Targeted Research). The results of SCEPTRE were designed to improve that throughout."

SCEPTRE was an AHDB Horticulture-funded project that concluded last year. The four-year programme tested some of the key "pipeline" conventional chemical and biocontrol products that were available for edible crops. It therefore saw more than 150 active substances or products tested, including yet-to-be-approved actives that were in the pipeline.

Biocontrols performed well in the experiments and, as a result, many new opportunities were identified. Gwynn explains that a new five-year £1.15m AHDB Horticulture project named AMBER (Application & Management of Biopesticides for Efficacy & Reliability) is succeeding SCEPTRE and focusing solely on the implementation of biocontrol agents. "SCEPTRE was about what each of the components is capable of doing," she says. "This one is about how best we implement them. The aim is to develop practical systems for improving the performance of market-available biopesticides for protected edibles, ornamentals and hardy nursery stock."

AHDB research and knowledge exchange manager Debbie Wilson adds: "It's really about making it (these products) work within the crop context, such as its root architecture and its canopy structure. First we are finding out what the products do in a crop and then we can develop best practice, because currently best practice is patchy within the industry. We are very much engaging with the companies that provide the products and with the growers that are using them. We are trying to pull all of that combined experience together and trying to get the products to perform as best as they can, given their constraints. So there will be a lot of communication over the five years of the programme."

Wilson adds that the details of the first year of the project were due to be agreed in March. "We are keen to get growers' input," she says. "There will be lots of opportunities for them to get involved. We will be running events on nurseries, for example. We want to know how people are getting on with them so we can help to make their experiences better for them."

John Adlam, managing director at horticultural consultancy Dove Associates, explains that the difficulty with using biocontrols on ornamental crops lies in the products' environmental constraints, such as their minimum temperature and humidity requirements.

"All of these aspects affect the efficacy of the product so you quite often get growers complaining of failure," he points out. Hopefully AMBER, the results of which are also expected to be applicable to the field vegetable sector, should address some of these issues.

Project extension

Meanwhile, another AHDB Horticulture project, MOPS (Managing Ornamental Plants Sustainably: Developing Integrated Plant Protection Strategies) looks likely to be extended for another year, to finish at the end of 2016. It is looking at how best to integrate conventional pesticides and biopesticides into IPM.

ADAS principal consultant John Atwood, who is leading the project, says: "We should really be looking to use biopesticides as much as possible. But we need to know the best way to use them because they are not like conventional fungicides. They are not as strong." He suggests that, in the short term, they are better used in situations where there is lower disease pressure so that growers can save the stronger conventional fungicides "for when you really need them."

AHDB Horticulture's other crop sectors, such as top and soft fruit, are also focusing their research on improving and fine-tuning growers' IPM. This includes identifying new predatory mites, for instance, as well as examining how biological controls are interacting with the chemical sprays used by growers.

For example, Professor Jerry Cross of East Malling Research, as part of AHDB Horticulture's long-term research programme on cane fruit pests and diseases, has looked at what happens to naturally occurring predatory mites and their capability to regulate two-spotted spider mite when growers apply their full programme of insecticides for raspberries. His data showed that although the predatory mite numbers were up and down, the spray programme definitely caused an increase in spider mite numbers. But, as Gwynn reminds us: "IPM practices are complex."

As all of this research bubbles away in the background, many growers and crop consultants have developed tips on how best to use biocontrols. Cucumber Growers Association technical officer Derek Hargreaves urges growers to put biocontrols into their glasshouses as early as possible. "The biggest problem is convincing growers to start using them early enough," he confirms.

"If you put Encarsia in when you see the first whitefly it's too late because when you see the first one how many thousands of others are in there already? And make sure you spread them across the block. If you just put them into the glasshouse and don't spread them you get a build-up of problems. It's a tiny wasp. It's not going to spread any distance."

Preventive targeting

Jasper Hubert, technical officer for biocontrols supplier Koppert Biological Systems, agrees that it is best practice to target pests preventively "before they even become a problem". He says: "Waiting for pests to arrive before taking action against them will be more problematic and expensive."

Adlam advises growers to "stick with it", adding: "It might not work the first time you do it but work with it. Do not give up early. Biocontrols work incredibly well, but it's not a case of spraying and expecting them to do the job irrespective of the conditions they are in."

As well as being patient, growers also need to be a little bit more intuitive, says Certis technical officer Alan Horgan. "People have to be more intelligent - more concerned about the details. Biopesticides tend to have a greater requirement than the traditional gunshot approach used with conventional chemicals. If you want a fungus to germinate you have to fulfil the criteria needed to germinate successfully."

In a similar vein, Hubert adds that it is worth getting a good understanding of the biology of the pest, particularly as the best control is achieved when all of the pest's life stages are targeted by several different beneficials. "Western flower thrips continue to be a serious pest in many fruit and ornamental crops despite the fact that there are several biocontrol products on the market that target them," he adds. "Many growers used to rely on one product, targeting one life stage, to give them protection. More and more are targeting all the life stages, using predatory mites for the larval stages, pirate bugs for the adults and soil predatory mites for the pupal stages. This results in much more reliable control."

Correct application

Fargro's Burnstone advises people to pay close attention to the label and technical information, pointing out that many biopesticide products are contact-acting. "It is essential that they are applied correctly in order to get the best out of them. The number-one reason for failure with any pesticide product is poor application and this is especially true for contact-acting products with no translaminar or translocated activity, such as current biopesticides.

"Growers should also think carefully about where these products might fit within their existing programmes. Some will work best when used preventively while others may have more curative activity. In all cases growers will want to have a robust monitoring system for pests and diseases in place so that products can be used at the right place and at the right time."

Meanwhile, Lallemand's Gough emphasises the importance of good communication among the horticulture sector. "It's vitally important that people understand that we have to work together. If these products don't agree with each other then that needs to be put out there. If they do work together that's a big step in the right direction."

The future of crop protection

As biotechnologists become better at utilising the wonders of nature, there is lots more wizardry in store. Gwynn predicts, for instance, that the future will see the optimisation of secondary compounds that microorganisms already have the ability to produce. "These can be used as PPPs," she says. "Normally they will produce them in situ but if companies can strengthen them it will increase the mode of action. We will also see a lot more botanicals - a wider range of plants and a much wider range of products."

Adlam adds that scientists are likely to develop new ways of combating the initial infection of the pests and diseases. "I think we are going to develop more ways in which we can get the plant to defend itself better," he predicts.

"The other area that has potential is the production of sterile males of the pest in question," he points out. "Perhaps, not through genetic modification but through gene therapy, we can switch off the reproductive ability of the male insect pests and as part of your IPM strategy you introduce a lot of sterile males. That way the breeding cycle is interrupted."

Gough believes that the future is going to see the industry continuing to focus on new varieties, working harder on nutrition and considering ecologies - and then using the chemistry that will be left. "Use all of that in a well-constructed way and you will succeed in getting what you used to bank on getting from chemicals - or possibly even more," he suggests.

Wider choice available for growers: a selection of new and best-selling biocontrol products

Given the rapid expansion of and investment in the biocontrols market, the choice of products continues to improve. Some of the latest developments include:

Macro-organisms (Natural predators)

Koppert Biological Systems

Biocontrol agents Spidex (Phytoseiulus persimilis) and Thripex (Neoseiulus cucumeris) continue to sell well, as does Koppert's NatuGro range, for which both fruit and ornamental growers reported some fantastic results last season, says technical officer Jasper Hubert. Koppert has also just released Aphiscout, a mixture of five different parasitic wasps that target various aphid species. "It can be used preventively in a wide variety of crops including salad, soft fruits and cane fruits," says Hubert. "The grower has less of a need to identify the aphid species and can enjoy better control of aphid pests in the crop."

Syngenta Bioline

Sygnenta Bioline has just released Stickline (pictured above), a "sachet on a stick" dispersal method for predatory mites Amblyseius cucumeris or Amblyseius swirskii. "We call it a lollipop," says Key account manager Dr Carolie Reid. "At the moment growers tend to use these mites loose in sachets, which can fall off pots and the like, so this new product can stick into the crop just like a lollipop and the mites will come out of the sachet as they naturally do but the sachets won't fall off."

The company is also looking to release two-spotted spider mite predator Amblyseius (Neoseiulus) californicus in a sachet later this year. Reid says: "Phytoseiulus persimilis is specific to red spider mite but you cannot use it in a sachet - it needs food. So this is the Holy Grail of spider mite control in a sachet because N. californicus will feed on pollen in the crops so you can put it in preventively, rather than curatively."

Syngenta Bioline also stocks Bugline, strips of sachets that come in a line, a bit like toilet roll. "It's been used in other countries for a while but we've not yet had a massive take-up in the UK," says Reid. "The grower can pull it down a row of plants and so get a line of Amblyseius down a crop. It means they don't have to put individual sachets in different places. It's very novel."


Biobest, whose products are distributed by Agralan, has just launched its Sphaerophoria-System based on pupae of the aphid predator Sphaerophoria rueppellii (hoverfly). During the nine-day larval stage, a single S. rueppellii can consume up to 200 aphids.

Brinkman UK

The Spanish Agrobio range of pollinators and beneficial insects was introduced to the UK this year by Brinkman UK.



Met52, a granular bioinsecticide for vine weevil control, has seen "excellent" growth in the ornamental and fruit sectors, according to Fargro technical officer Dr Joshua Burnstone, while bioinsecticides Naturalis-L for whitefly and thrips, and AQ-10 for powdery mildew have also shown good results.

Bayer CropScience

Tim Lacey, Bayer CropScience product manager for biological roots and horticulture, notes that biofungicide Serenade ASO is currently the company's fastest-selling biopesticide, while biofungicide Contan WG, which is primarily used by the leafy salads industry, is also now being used on some other crops including potatoes and carrots.

Bayer's bionematicide Flocter, currently being trialled in the UK, is showing a lot of potential. "We have had some good trials but want to do a bit more work on reducing the dose per hectare to get it to a more viable cost for the grower," Lacey explains.

Bayer is also hoping to gain registration - initially for glasshouse crops and later for open-field crops - towards the end of 2018 for a new bioinsecticide that targets sucking pests.

Lallemand Plant Care

Lallemand's biological fungicide Prestop is now being exclusively marketed in the UK and Ireland by ICL (formerly Everris) and its distributors. The product continues to be a popular choice because it provides effective control of a wide variety of plant pathogens in crops such as fruits, ornamentals and protected salads.


BASF hopes to soon gain registration for its RAK3+4 pheromone product, which has performed well in UK orchard trials when used with Nemasys C to tackle codling moths (larva pictured above).


Certis reveals that its bioinsecticide Botanigard WP has gained an EAMU this year for controlling both whitefly and thrips on outdoor and protected strawberry crops.

S&A Produce: soft-fruit grower based in Herefordshire has been using predators to combat pests for the past three years - image: S&A Group

Case study: S&A Produce tackling troublesome thrips with predators

S&A Produce used to have big problems with thrips but has now successfully combated this bothersome pest thanks to the use of biocontrols.

Roger Vogels, director of soft-fruit growing for the Herefordshire-based grower, says: "We had experienced big issues with thrips but now, having used predators for the past three years to combat them, I am very confident with them (biocontrols) as there is no chemical control for thrips. I cannot see us growing strawberries commercially without the introduction of predators."

He reveals that S&A Produce uses predators such as Neoseiulus cucumeris for thrips and Phytoseiulus persimilis for red spider mites. These are added to most of the growing cycles for around 10 months of the year. The company has used biocontrols for the past 15 years, mainly bees for pollination, but during the past five years it has used an array of various predators.

Vogels adds: "With an ever-depleting list of chemicals, insects are becoming harder to control. We have found there are cases of resistance to chemicals and pests can never become resistant to being eaten. Harvest intervals are also critical within soft fruits and biopredators have no harvest intervals."

He notes that storage is important when using these products because they are "live" and "need treating with respect". Understanding the predator's life cycles and how they work is key, he adds. "Understanding this helps with how and where to apply them. Cold or hot weather can also be a challenge."

While there is different equipment available for applying predators, he explains: "For us the best way is by hand as it gives the opportunity to adjust rates over the crop where there are hotspots." Vogels hopes to see continued research into finding new predators for pests that come along such as spotted-wing drosophila and he would like to think that "we can grow crops without the use of pesticides".

Eric Wall: tomato grower has made use of biocontrols for more than 20 years - image: Eric Wall

Case study: Eric Wall finds chemical use is a last resort in tomato industry

West Sussex tomato grower Eric Wall has been using biocontrols for more than 20 years now and commercial manager Paul Faulkner notes that the tomato sector as a whole has really embraced biocontrol and uses it confidently, with chemical intervention being a last resort.

"Biocontrols are already the most common method to control pests and diseases across our industry," he says. "No grower wants to be applying chemical sprays if it can be avoided. I think the tomato sector is very forward-thinking in its approach and welcomes the innovation that takes place on the various products."

He adds that the company very much believes in "doing the right thing" and biocontrol fits right into this approach. "The working environment for the team is much better and cleaner with biocontrols and it aligns with our broader commitment to biodiversity.

"When hosting visits to our nursery, whether for local schools or societies, people are always taken by the work we do with natural predators - or 'mini beasts'. It's a great way to engage with the local community as well as highlighting the great work that's taking place across protected horticulture. Last year we were awarded LEAF (Linking Environment & Farming) demonstration farm status and the use of biocontrols is strongly linked with that work."

Faulkner reveals that Eric Wall uses four key biocontrols - Encarsia formosa for whitefly control, Macrolophus pygmeus for most pests, Phytoseiulus persimilis for spider mites and Diglyphus isaea for leaf miners.

"Each year we face different growing pest and disease issues and we will use all of these biocontrols throughout the season, with quantities varying dependent on the challenges we face," he adds. "We are fortunate to have a very experienced team, with one team member specialising in biocontrols. Together with our growing manager and the advice we receive from Koppert, the experience we have across the team enables us to identify issues early and respond appropriately.

"We are also very fortunate within our industry that through various trade bodies (the Tomato Growers Association, the Tomato Working Party and the Tomato Study Group) we get the opportunity to share best practice on a regular basis with other growers."

He notes that such close collaboration is essential, especially when a new pest arrives. Tuta absoluta, for example, is a pest that appeared a few years ago now. "The impact of this on the industry was quite severe but by sharing knowledge and using bio-like Encarsia pre-emptively we have much better control now," says Faulkner. "This is a great example of how the industry pulled together and shared best practice."

Viking Nurseries: hardy nursery stock producer is using Prestop as part of its integrated pest management programme - image: Viking Nurseries

Case study: Viking Nurseries utilises biofungicide Prestop to help its lavender crop to thrive

Lavender is thriving at Viking Nurseries thanks in large part to the introduction onto the crop of the biofungicide Prestop. The hardy nursery stock producer based in Norfolk has been using the Lallemand Plant Care product for three years now as part of its IPM, which strives to be a full biopesticides programme when possible.

Assistant production manager Robert Walton says: "I think the industry is going to be 100 per cent biological controls in five-to-10 years' time anyway, so we are just trying to get ahead of the game. It's a good selling point for us as well."

He adds: "We mainly use Prestop for Botrytis and it's been giving us good control for a while. If you apply it in optimum conditions you can get four if not six weeks' control. It's particularly good on lavender crops and we've also had good results with it on our liner-sized rhododendrons and euonymus."

Prestop contains the mycelia and spores of the naturally occurring soil fungus Gliocladium catenulatum strain J1446. It provides a number of very useful disease control benefits through multiple modes of action. For example, it works as a hyperparasite through its production of enzymes, which cause the breakdown of plant pathogen cell walls.

It also deprives pathogenic fungi of living space and nourishments by colonising the surface of roots and aerial plant parts. Walton notes that the product is most effective at temperatures above 10 degsC but says he has used it at 5 degsC so it has the added benefit of working well when it is cold.

Posktt: Big testing year for NEMguard

Case study: MH Poskitt turns to garlic-based bionematicide NEMguard

North Yorkshire-based root crop producer MH Poskitt had been using DuPont's conventional chemical product Vydate for nematode control until an unusual turn of events prompted the firm to use ECOSpray's garlic-based bionematicide NEMguard instead.

Grower Guy Poskitt explains: "There was a devastating explosion at the Vydate factory near Houston, Texas, which caused some fatalities. US health and safety teams closed the factory down and that's gone on for a while now as there's no Vydate available this year.

"So this is the first time we have used NEMguard on all of our crops, although we had been trialling itwith Certis for a number of years. We've used it at sowing time on our carrots and parsnips. It comes in a granular form and so it's applied the same way as Vydate.

"I think it's worked but nematodes are not an easy thing to treat because the damage caused by them is not predictable. Whether there had been no nematode activity or whether the Vydate worked I could not tell. This will be a big testing year for us. If we have good results this year we might not use Vydate again."

Braime: knocked glasshouse whitefly populations for six using Botanigard WP - image: Double H Nurseries

Case study: Double H Nurseries controlling whitefly with bioinsecticide

Hampshire-based Double H Nurseries, which primarily grows protected begonias, pot chrysanthemums, mini roses and orchids, had been finding it a challenge to control glasshouse whitefly. Technical manager Howard Braime therefore decided to incorporate Certis's bioinsecticide Botanigard WP into his IPM programme last June.

Botanigard WP contains the fungus Beauveria bassiana and works on the pest by producing spores that stick to the insect's cuticle and then germinate. The fungus's hyphae penetrate the cuticle and continue to grow inside the insect, overwhelming its immune system and causing the pest to die after five-to-seven days.

Braime says: "As a result of using Botanigard we've knocked the glasshouse whitefly populations in the roses, chrysanthemums and other crops for six in a very short time. We've also reduced insecticide usage in the roses and chrysanthemums by 60 per cent."

He adds that the product has also given incidental control of western flower thrips, which he had been struggling to get rid of in his rose crop. "It's wiped out the thrips and we've been using it on our rose crop every week throughout the winter." He advises other growers to apply the product late in the evening, when ultraviolet levels are low, and to keep humidity levels up.

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