Mar 20 2019

Amino acid biostimulants: Relief for stressed-out veg crops

Following a year of unprecedented weather extremes and challenges to plant health, we outline how amino acid biostimulants can help farmers tackle the worsening challenges involved in producing high-quality, high-yielding vegetable crops.

Crops and climate change

Up there with the heatwave of 1976, the long, hot summer of 2018 was tough on the UK’s crops. Veg shortages hit the headlines last year; in July the Guardian reported a 22% fall in lettuce yields as plants wilted in the dry, relentless heat. This shortfall in green material was at odds with a 40% surge in demand, as people enjoyed more alfresco salads. With similar stories seen everywhere from arable crops to carrots, news outlets speculated on what impact extreme weather patterns and dwindling veg yields might have on the UK’s food supply – especially come Veganuary! Alarmingly, findings in December’s Climate Predictions Report from the Met Office confirmed that the UK can expect warmer, wetter winters and hotter, drier summers going forward, with an increase in frequency and intensity of extremes. As demand on growers and their crops becomes ever more fierce, agricultural productivity is facing threat from a variety of stress factors, many associated with a changing climate.

A better way

It’s clear that we need to change the way we think about growing. At Interagro, we are certain that unlocking the genetic potential of plants and building resilience into crops are the greatest agricultural challenges of our time. Amino acid biostimulants are the key to overcoming these barriers, promoting vitality during establishment, optimising metabolic efficiency, aiding resistance to environmental stress conditions, and working in harmony with nature to produce a healthy, high-yield vegetable crop.

The building blocks of all living cells, amino acids combine in infinite variations to produce various proteins essential for healthy growth and development. Under ideal conditions, plants synthesise all 18 L-amino acids, using carbon and oxygen in the air, hydrogen from water and nitrogen from the soil. This is what makes soil quality and nutrient density so important to overall plant health. In punishing conditions, these raw materials can leach away in the soil or become inaccessible. When supply of amino acids becomes limited as the result of extreme temperatures, drought, flooding, pests or phytotoxicity, amino acid production slows and plants start to self-cannibalise. Where plants aren’t getting what they need from their environment, we believe working with biostimulants is the best way to break this cycle.

On the ground

So what are biostimulants – and just how big a difference are we talking in terms of growing veg? Without nutrients and pesticides, biostimulants are substances with the capacity to modify the plant processes. Feeding the crop extra L-amino acids via the roots or leaf tissue before, during or after a stress event optimises its ability to access essential nutrients and water, giving the plant the building blocks necessary to prevent self-destruction and aid repair. Still relatively new on the scene, we’re only just beginning to understand the potential of these new and exciting incremental technologies. Our Bridgeway product contains all 18 L-amino acids required to assist with plant functions and healthy development. In 2018, we sought the help of farmers and agronomists to explore its potential benefits in vegetables. The results were better than we could have imagined…

Brussels sprouts

Loved and loathed in equal measure, the height and biomass of brussels sprouts plants (or brussels sprouts’ plants)means they require plenty of healthy soil – and attention. Nutritionally, sprouts love calcium and magnesium and are big users of nitrogen and potash. A lack of available chemistry to control weeds and pests spells bad news for production. Nitrogen and water are essential for helping plants reach the height necessary – but aren’t always available to the crop. Bridgeway exhibited significant benefits in sprouts; applied six times at a rate of 2 L/ha, it improved overall yields by 11.8 t/ha and produced strong, healthy plants that showed signs of being able to better fight disease.


Growing onions is not for the faint-hearted. Costly to grow and difficult to protect, onions tend to be uncompetitive against weeds and possess limited actives to ward off yield-sapping diseases. The balance between herbicides, fungicides and irrigation has to be carefully managed – wet foliage provides the ideal conditions for downy mildew. Fine, sprawling and twisted, onion roots also struggle to seek out nutrition. For these reasons and more, it’s essential to get your onion crops off to a strong start. Trialled in onions in 2018, three applications of Bridgeway at 2 L/ha increased yield by as much as 7.24 t/ha.


In 2018, the Guardian commented on a 25% fall in potato yield, while the BBC reported a hike in prices for consumers. How can we avoid another situation like this in 2019 and beyond? The production of a fit and health potato crop is no easy task. A thirsty crop requiring plenty of water early in the season just for canopy development, growing potatoes requires managing a whole host of diseases, weeds, pests and disorders with a limited toolbox. Bridgeway has shown consistent benefits in root crops, increasing bulking by up to 2.2 t/ha per week and yield by up to 12.4 t/ha.

With no silver bullet to tackle all agricultural challenges, producing a profitable veg crop relies on integrating all the available tools.  

Recommendations 2019

Getting the most from your biostimulant application is more an art than an exact science. Although the product can be used on all crops throughout growth without restriction, the perfect application timing may well differ from farm to farm, crop to crop or field to field. Every crop could be at a slightly different stage of development and it can be hard to predict when a crop is likely to experience stress. Applying timely applications ensures plants are suitably prepared to deal with these conditions as they arise.

To talk through individual scenarios or to request a copy of our Bridgeway product/timing/case study guides, please get in touch:

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Require technical assistance or product information? Please get in touch with our Technical Manager, Stuart Sutherland.

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