May 27 2020

Relief for stressed out potato crops

Beat stress and protect potential with Bridgeway/Zonda

Keeping potato crops stress free is vital to protect yield and quality potential. But in a year where mother nature just keeps on giving, it’s a challenge that is quickly becoming a nightmare for most potato growers and their agronomists.

Whilst potato planting was completed in good conditions and in record time, growing conditions have become a lot more challenging, and it’s not just farmers and their agronomists feeling the stress, crops are also now feeling the heat too…..and the drought, frost damage, wind blow, very high UV levels, and not to mention the herbicide damage to some crops.

However, crop stress, which reduces the rate of carbon assimilation and decreases partitioning of assimilates to the tubers, is the most detrimental to tuberization, bulking and tuber yield. Beating stress is therefore a necessity to protect yield and quality potential. With the potato tuber being mainly composed of photoassimilates (mostly starch), any mechanism to stimulate photosynthesis and translocation of the end product to the underground stem offers the possibility to increase tuber yield. Biostimulants Bridgeway and Zonda offer the perfect solution to growers to help reduce stress by improving root health and by increasing the rate of photosynthesis, enabling starch production to continue. Amino acids and peptides in Bridgeway/Zonda also help to alleviate stress and help the crop to tolerate and recover from stress scenarios.


The impact of stress on the potato crop

Temperature stress

Temperature stress can affect potato crops at any time during the growing cycle. Fluctuations in temperature between hot and cold, as we have experienced recently, lead to erratic growth that cause issue with tuber size, numbers and impacts quality, often resulting in growth cracks. Sensitive to both minus temperatures and extreme heat, potato plants stop growing above 26 oC as they physically cannot draw enough water up to compensate for what they are losing through their leaves.  Such extremes later on can stunt the canopy or prematurely senesce it impacting tuber size and yield.

Drought stress

With rainfall at 64% of the national average for March/April, and May shaping-up to be the driest on record, drought stress will be a major problem where crops remain unirrigated. Only certain varieties will be able to cope and any further extremes, wet or heat, will exacerbate the stress impact on the crop.

Frost damage

Alongside the sub-zero conditions, May’s frosts caused severe damage to early and early-maincrop potatoes in some low-lying areas of the country. Recovery of the crop will depend partly on the variety and also on the growth stage. Whilst affected crops can normally resprought, growth will be set back weeks and will likely impact final yield and lifting date.

Wind blow

Wind blow can happen anywhere, but tends to be more of an issue on the fens under very specific weather conditions, which some growers will have experienced recently. In situations where the crop must tolerate wet, dry, then wet, followed by strong winds, damage to the crop can be severe with the wind causing shear to the stems or damage to leaves.

Very high UV levels

This year has already proved to be a scorcher, with the Met Office reporting April 2020 as the sunniest on record and 144% of the average for 1981-2010. With the sunny conditions having continued through May, the very high UV levels have led to rapid growth of the crop. Whilst it is too early to tell at the moment if this will be to the detriment of the crop, it may lead to smaller canopies and lead to lower tuber numbers per plant.

Herbicide stress

With the loss of diquat from the weed control toolbox this spring, potato growers have been under even greater pressure to ensure residual herbicide sprays have been both timely and effective, particularly as soils have dried quickly across the country. Again weather conditions play an important part, and where heavy rain has occurred after application, some herbicide has been washed down to the root zone and taken up the plant causing a little mottling of the leaves. In severe cases, complete yellowing of leaves and stem can occur, knocking the plant back due to lost growth and the crop will normally take time to recover.

With drought fears for the rest of the season, coupled with the prolonged hot high UV levels forecast for the weeks ahead, potato crops are about to come under high stress if they have not done so already. Biostimulants Bridgeway and Zonda have been developed with these very challenges in mind and will help alleviate stress on the crop and deliver tolerance to stress moving forward.

Bridgeway/Zonda – relief for stressed out potato crops

Stress-busting biostimulants Bridgeway and Zonda have proven highly effective in helping potato crops to cope better with abiotic stress. Amino acids Proline and Serine help the crop to rebuild catabolised structural proteins whilst crucial signalling peptides aid physiological changes in the plant that trigger vital coping and recovery mechanisms.

Bridgeway/Zonda applications:

  • Stimulate root growth increasing the crop’s access to water and nutrients, crucial during periods of heat, drought and nutrient stress
  • Stimulate shoot growth and regulate growth and development, helping the crop to recover crucial biomass for photosynthesis after frost and herbicide stress
  • Increase metabolic efficiency by increasing the rate of photosynthesis and N assimilation, crucial during periods of stress
  • Produce fitter plants with greater resilience to disease and abiotic stress
  • Produce healthier crops that can help protect yield and quality potential

Significant yield and margin benefits year after year

2017 trials - Heat & drought stress - Bridgeway increased tuber yield at all application timings

Effect of Bridgeway on tuber yield (t/ha). All Bridgeway treatments applied at 2.0 L/ha

CMI - 2017. Potatoes cv. Desiree. Planted 9th May nr Wilsford, Lincolnshire. Overall yield assessment P= 0.0007

2018 - Timing trial 1 - Heat stress - Bridgeway increased yield and margins significantly

Effect of Bridgeway on tuber yield (t/ha) and margin over input costs (£). All Bridgeway treatments applied at 2.0 L/ha

CMI 2018, Doncaster. Potatoes cv. Russet Burbank. Yields taken from 6th test digs 2nd Oct. P = 0.0033. Potatoes at £175/t. MOIC based on Bridgeway at £10/L.

2018 - Timing trial 2 - Heat stress - Bridgeway increased yield and margins significantly

Effect of Bridgeway on tuber yield (t/ha) and margin over input cost (£). All Bridgeway treatments applied at 2.0 L/ha.

CMI 2018, Lincolnshire. Potatoes cv. King Edward. P = 0.0011. Mean yield from harvest 5 & 6. SD = Significant difference.

2019 trials - Early drought stress - Bridgeway increased yield and margins significantly. Three applications optimal

Effect of Bridgeway on tuber yield (t/ha) and margin over input cost (£). All Bridgeway treatments applied at 2.0 L/ha

CMI 2019, Wilsford. Potatoes cv. Sapphire. P = 0.002. Harvested 6th September. SD = Significant difference. Potatoes at £175/t. Margins based on Bridgeway £10/L

Find out more about the recovery benefits of Bridgeway/Zonda 

From disaster to success with Bridgeway

Bridgeway helped Sugar Beet recover from herbicide damage

How to use Bridgeway/Zonda

For more information on how to use Bridgeway/Zonda in potatoes and other key crops, please request a product guide on the Bridgeway / Zonda product page.

Maintain blight control

With many soils across the country turning to dust, there may be the temptation by growers to reduce blight spray applications or extend the window between applications. However, with the high UV intensity and rapid growth, lush forward crops will need protecting to keep blight out, particularly where humid conditions may become indispersed with a sprinkling of rain. It’s not uncommon for small areas of infection to remain hidden until late into the growing season or, worse still, when in cold stores.

Maximise fungicide performance with Crusade

The anti-drift agent Crusade will not only help to maximise spray deposition on to the crop, as a result of reducing drift, it will also help to ensure maximum coverage to the full potato canopy so fungicide performance is maximised to prevent blight infection.

How to use Crusade

For information on how to use Crusade in potatoes, please request a copy of our product guide on the Crusade product page and we’ll get a copy right over to you.





For more information on Bridgeway/Zonda & Crusade

Get in touch

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

For all other general enquiries, please email or call us at the office. If you’d prefer, drop us a message using our contact form and we’ll get back to you as soon as possible.

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