As chemical efficacy declines, the threat of disease and pests to UK growers is on the rise. However, Todd Jex, agronomist at Agrii, believes that using biostimulants to boost plant health could help alleviate some of the pressures.

“One of the biggest challenges that the industry is facing at the moment is that we are losing more and more protection products from the arsenal – coinciding with increased disease and pest pressures.

As these pressures rise, so does the risk of stress on crops. For cereal growers – particularly those producing barley – stress can have a detrimental effect on overall crop performance. Ramularia is one disease where we are especially seeing resistance issues. We also know it is directly linked to stress, so anything we can do to reduce this is beneficial, and this is where biostimulants come into their own.

With crop protection efficacy on the decline, farmers and agronomists have been looking at more ‘out of the box’ ideas which has led to the surge in interest around biostimulants. These amino-acid products have proven benefits in protecting crops from stress periods – such as drought – as well as benefiting overall crop health and subsequently yield.

Agrii has been carrying out trials on Interagro’s product Zonda over the past few years. In a split field trial last year, we applied Zonda to spring barley at T1 – at a dose rate of 1 l/ha. Obviously, last season there were extreme pressures on crops due to the prolonged dry period, but just a week after application the crop was looking visibly greener and much less stressed.

Reducing the impact of stress exposure can undoubtedly have a positive effect on yield, and in the spring barley trials last year we saw an average yield uplift of 0.2t/ha. When you’re getting uplifts like this, the return on investment more than pays for the cost of the product.

With the proven results, this year we are repeating the trial on a bigger scale and are also experimenting with T1 applications in wheat for the first time. There is a lot of evidence to say that earlier applications can have a greater impact, but obviously this has to stack up financially too, so we’ll be looking into that in more detail this year.

If we turn our focus to the current growing season, crops in the South/South West of the country are looking well, especially following the recent rainfall. However, concerns are still there on some of the lighter, chalk soils where spring barley in particular is looking a bit stressed.

With the summer months leading up to harvest set to be incredibly dry, biostimulants could play a critical role in keeping crops healthy.”


The best way of testing the benefits is doing a trial on your own farm. Going forward, plant health is going to become a much more prevalent part of crop production and anything we can use to boost this is definitely worthwhile investing in.

Todd Jex, Agronomist, Agrii