Crop protection - Finding effective defences

Market consolidation, a mild winter and the loss of established products are all challenges but some new options are emerging for growers, Gavin McEwan reports.

Brassicas: Syngenta insecticide Cruiser 70WS applied via Phyto-Drip technology in a fully controlled glasshouse environment - image: Syngenta
Brassicas: Syngenta insecticide Cruiser 70WS applied via Phyto-Drip technology in a fully controlled glasshouse environment - image: Syngenta

Any let-up is unlikely in the challenges of controlling pests, diseases and weeds in fresh-produce crops in 2016, with the effects of a (so far) mild winter adding to the incremental restricting or withdrawal of established products, while fewer new products are successfully being brought through the lengthy and costly approvals process to market.

Meanwhile, concern has been expressed at ongoing consolidation in the $50bn (£35bn) global crop-protection market. Last month’s merger between US firms DuPont and Dow Chemical, combined with continued speculation over the future ownership of Swiss-based Syngenta, "is creating a marketplace where farmers will have very few alternatives for purchasing inputs", according to America’s National Farmers Union.

President Roger Johnson adds that a reduction from six to five major global players in the market would "almost certainly" increase the pressure for remaining companies to merge, leading to even less competition and innovation as well as potentially higher costs.

Last month Dow also committed to become one of the top three crop-protection companies worldwide. European commercial director Eric Dereudre says: "Our pipeline of innovation and technology is probably the best it has ever been. For us, innovation means ever more sophisticated chemistry."

The firm says new chemistry and new modes of action in its products "will help meet the increasing challenge of resistance to many established pesticides". But it warns: "The speed of introduction of these new products will be governed in part by the regulatory process, which can take longer in Europe than elsewhere in the world."

Products that will enter the UK and Irish markets over the next few years include the broad-leaf herbicide Arylex and a systemic foliar insecticide, Isoclast. The company will also move its UK and Ireland headquarters to new premises in Cambridge this year.

Existing products

Bayer CropScience product manager Claire Matthewman tells HW: "It’s hard to get new products through [the approvals process] so we are looking to do more with our existing ones." This includes an extension of use for "one of our insecticides" to cover onions and potatoes expected shortly, with a further extension to carrots to follow. "This will be particularly welcomed by onion growers as there are not many options against onion thrips," she points out.

Bayer product manager for biologicals Tim Lacey adds: "Round the corner, we have a novel insecticide based on plant extracts for sucking pests that we are hoping to have authorisation for in the UK in the next couple of years. This will be for protected crops initially, with the intention to broaden to field crops. We also hope to bring another biological fungicide to the market in the same sort of timescale, largely targeting powdery mildews."

Syngenta has released a new insecticide treatment for module- and block-raised brassica and salad crops, giving plants up to eight weeks of protection against a wide range of aphid pests including Myzus persicae and Brevicoryne brassicae after planting. Cruiser 70WS is a new liquid formulation
of the insecticide Thiamethoxam.

It is approved exclusively for treatment applied via Syngenta’s Phyto-Drip technology.

The fully automated system delivers an extremely accurate dose in a single droplet of treatment onto a pre-seeded cell block. This is applied in a fully controlled glasshouse environment, with no risk for operators handling treated seed or to the wider environment.

The Cruiser 70WS is then rapidly absorbed through roots and translocated evenly throughout the leaves at a steady rate as the young plant grows.

The withdrawal of dummy pill treatments had left brassica growers with fewer options for effective early-season insect pest control, according to Syngenta insecticide technical manager Pete Saunders. "Crucially for aphid control, Cruiser 70WS can help to prevent build-up of aphid populations resistant to other insecticide treatments, which will reduce pressure on other crops and achieve better results with foliar programmes," he explains.

The loss of neonicotinoid seed treatment in oilseed rape also meant vegetable growers had to contend with record levels of M. persicae last spring, he says. "The approval of Cruiser 70WS for brassicas and salads could help reduce this increasing pressure." Salad crop trials have shown a 95 per cent overall control of the most problematic aphids seven weeks after planting, he adds.

While Cruiser 70WS can provide complete control of aphids through to harvest in fast-growing salad crops in low pest-pressure situations, longer-growing crops and high-risk situations may require additional foliar treatments, including programmes utilising Plenum and Hallmark Zeon, depending on aphid species, Saunders advises. "Growers should be talking to their young-plant suppliers at the earliest opportunity to plan in requirements for the coming season."

Newly gained approval

Another crop-protection product to have newly gained UK approval is the non-systemic fungicide Prolectus, manufactured by Japan's Sumitomo and marketed by Nufarm UK. Based on the active ingredient fenpyrazamine, it controls grey mould (Botrytis cinerea) in wine grapes, outdoor and protected strawberries, protected crops of tomatoes, aubergines, peppers, cucumbers and courgettes.

According to Nufarm UK business manager Simon Bishop: "In trials, it has also shown good activity on Sclerotinia sclerotiorum, Monilinia and Pseudocercosporella [white leaf spot], giving protective as well as significant curative control. It acts by inhibiting germ tube elongation, mycelial growth and has some anti-sporulant properties."

In trials and commercial use in Italy, Prolectus has performed as well as or better than the standard fungicide treatments currently used, he adds, but he suggests it should be used as a part of a programme and sequenced with products with a different mode of action to minimise the risk of resistance.

On herbicides, the European Food Safety Authority (EFSA) has published a peer review of the active ingredient glyphosate as part of the EU renewal process, concluding that it "is unlikely to pose a carcinogenic hazard to humans and the evidence does not support classification with regard to its carcinogenic potential". This counters a claim earlier last year by the World Health Organisation’s International Agency for Research on Cancer that the chemical is "probably carcinogenic to humans".

Nick von Westenholz, chief executive of UK industry body the Crop Protection Association, says: "We are pleased to see that EFSA concurs with the numerous health assessments conducted by public authorities on glyphosate over the past 40 years which have all concluded that, when used correctly, it poses no meaningful risk to human health.

"Glyphosate is an important part of a farmer’s and gardener’s toolbox. It is particularly important in minimising food waste by controlling a broad spectrum of weeds and therefore reducing the need for ploughing of soils. This protects soils from degradation and reduces greenhouse gas emissions and energy consumption. This is just one example of how modern farming relies on innovations in crop protection such as glyphosate to protect soil while helping make our land as productive as possible."

However, the AHDB has warned of the danger of weeds developing resistance to glyphosate and last year published a guide, available from its website (, to help growers minimise the risk of this.

Meanwhile, the progress of biological controls in crop production is being stymied by the ongoing delay in a report due from the European Commission on increased use of alternatives for pest and disease control, according to the International Biocontrol Manufacturers Association (IBMA). The EU Sustainable Use Directive requires this report to set member states’ quantitative objectives, targets, measures and timetables for implementation of sustainable integrated pest management (IPM), originally setting a deadline of 26 November 2014.

The Food & Veterinary Office, the EU body controlling the implementation of the directive in member states, concluded from two audits last year in Austria and Italy that "there is no system to verify that all professional users implement the general principles of IPM".

IBMA executive director David Cary says: "Innovative solutions need innovative regulation but it has to be enacted and enforced." Association president Dr Willem Ravensberg adds: "IPM is proven to be working in many cropping systems. What is keeping broader adoption from occurring?"

Bumblebee Innovation

One new innovation in biological controls set to be trialled in the UK later this year is the use of commercially reared bumblebees to deliver spores of biological pesticides to flowering crops. Developed in Canada by Bee Vectoring Technology and based on 20 years of research and eight years of trials, the technique is now being commercialised internationally.

The company says it brings efficiency, cost savings and a reduction in water usage for the grower, while also extending product shelf life. It has been developed for a wide variety of crops including apples, pears, strawberries, tomatoes, field cucurbits and others.

Aerial application

A Chinese company has developed what it claims is the first unmanned aerial vehicle (UAV, or "drone") capable of systematically applying pesticides to field crops.

The eight-rotor DJI Agras MG-1 can carry more than 10kg of liquid product and can fly up to 8m per second (29kmh), allowing it to cover 3-4ha per hour. It adjusts spraying intensity to flying speed to ensure even coverage, while automatically maintaining a fixed height and distance from plants. After refilling or recharging, it resumes spraying where it left off.

DJI founder and chief executive Frank Wang says: "With this new product, we’ve shown that DJI can not only offer the ultimate aerial experience for the mass consumer but also improve the efficiency of production." The Agras MG-1 will initially be available in China and Korea, and later in other markets, according to the company.

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