Keeping potatoes stress-free is not an easy task, especially with crops often subject to prolonged stress periods at key growth timings.

However, ahead of a new season, an amino acid-based biostimulant could be the answer to protecting potential, particularly in the early stages, according to the latest advice from Interagro.

Early crop stress reduces the rate of carbon assimilation and decreases partitioning of assimilates to the tuber and can be incredibly detrimental to tuberisation, bulking and tuber yield.

Managing stress, and mitigating against it where possible is, therefore, essential in order to protect yield potential.

Stress can come in all shapes and forms, dictated largely by the weather, explained Stuart Sutherland, the technical manager at Interagro.

“One of the key contributors to potato stress is temperature. Temperature stress can affect potato crops at any time during the growing cycle," he said.

"Fluctuations between hot and cold often lead to erratic growth that cause issues with tuber size and numbers – and also impacts quality – which can result in growth cracks.”

Other weather influences such as drought and frost, as well as wind blow, can also have an impact, he adds. “Arguably, these factors are often out of the control of growers, so anything they can do to minimise stress and maximise photosynthesis will no doubt be hugely beneficial for profitable potato production.”

With the potato tuber being mainly composed of photo-assimilates, mostly starch, any mechanism to stimulate photosynthesis and translocation of the end product to the underground stem offers the possibility to increase tuber yield, and this is where Interago’s biostimulant, Bridgeway, is particularly useful, he argued.

“Bridgeway offers the possibility to reduce stress by improving root health and by increasing the rate of photosynthesis to optimise tuber bulking. During establishment and growth, it stimulates rooting, enabling the crop to draw on water and nutrients from depth, while supporting the larger canopy as the season develops," he said.

"This is particularly beneficial during drought stress periods. Stimulation of shoot growth is also somewhat helpful for aiding quick recovery if crops become damaged by frost."

In terms of stress tolerance, the amino acids and peptides in Bridgeway signal defence and recovery mechanisms in the plant, explained Mr Sutherland. “Regular applications of Bridgeway will help to build resilience to stress during the growing season and ensure tuber bulking continues, even during stressful growing conditions. As a result, Bridgeway-treated plants invariably yield higher.”

Looking at crop efficiency, it can also increase the rate of photosynthesis, he pointed out. “The adverse effects of abiotic stress on the crop can be limited with Bridgeway, which trigger stress defence mechanisms and increases the photosynthetic light conversion efficiency of the crop.

"The subsequent translocation of assimilates to the underground stem ensures tuber bulking continues and helps to ensure resilient high yielding potato production.”

Its positive effects have been proven continuously in trials over the past four years. “The growing season of 2020 was particularly tough on crops and growers alike, with Bridgeway-treated crops faring better than most,” he added.

The trial results for 2019

The trial results for 2019

During 2017, 2018 and 2019, CMI investigated the effect of its use in commercial potato crops. The trials investigated the influence of different application timings and sequences on growth and yield of in the trials.

In all of them, crop husbandry was even across the site and management aimed to remove all constraints other than those under investigation – all sites were irrigated with drip irrigation.

“The 2018 trials showed that three applications were optimal for getting the most out of Bridgeway," explained Mr Sutherland. “In terms of overall tuber yield, the treated crops were found to boost yield by 5.1t/ha and deliver the highest margin over input cost of £857/ha. Similar results were also seen in subsequent years.”

In light of the variability seen over the past few seasons, using Bridgeway is a no-brainer this season, he concluded. “Trials have continually proven that Bridgeway is the best-in-class biostimulant to reduce stress and protect potential in potato crops.

"When so much is out of our control, why leave it to chance when it comes to giving your crops the best chance of thriving this season?”