Rethinking Fungicide Applications in a Low-Yield Year: Investing in Crop Resilience

Many UK farmers face an unusual scenario this season—extended dry conditions resulting in significantly reduced disease pressure on winter wheat crops. Conventional advice often frames fungicide applications as an "insurance policy" against disease. But is this truly the best investment in a year when potential yields are inherently compromised by drought?

It's worth considering an alternative perspective: perhaps this is not simply a year with low disease pressure but, fundamentally, a year with low yield potential. Modern wheat varieties are bred specifically to maximise yield under optimal conditions—ample nitrogen and ideal moisture—but can lack the resilience possessed by their landrace and wild relatives during stressful times. Research indicates that intensive yield and nitrogen responsiveness breeding often comes at the cost of drought resilience and stress tolerance (Araus et al., 2008; Foulkes et al., 2011).

Furthermore, the efficiency of nitrogen use—both in uptake from the soil and utilisation within the plant—plummets under drought conditions (Hawkesford, 2014). This means that even the best fertilisation strategies struggle to deliver optimal yields during drought stress. Essentially, this year, there is no high yield to protect. Thus, the standard justification for high-cost fungicide applications (£60/ha or more) deserves scrutiny.

Manufacturers promote fungicides with additional claims beyond disease control, such as improved stomatal regulation and enhanced root growth. However, robust independent evidence supporting these claims under drought conditions remains sparse. Farmers must critically evaluate such assertions. Ask yourself: is the supposed drought benefit truly worth £40/ha or more? Where is the data? Are those advocating a particular product financially incentivised? We are too easily content with ONE explanation for a benefit, as Rory Sutherland would say, “the lazy why.”

Rather than heavily investing in fungicides when disease pressure is demonstrably low, a more strategic allocation of resources could involve directly bolstering crop resilience. Allocating approximately £20/ha towards proven biostimulants—such as seaweed extracts and amino acids—could enhance the crop's physiological ability to withstand drought stress, thereby improving overall resilience (Calvo et al., 2014; Khan et al., 2009).

Indeed, a modest fungicide application at approximately £20/ha could offer peace of mind against unexpected disease outbreaks. However, reallocating part of the budget toward crop nutrition and biostimulants may yield a significantly better return on investment during a drought.

Critically evaluate conventional wisdom. Challenge assumptions. Does applying a costly fungicide in a drought year genuinely justify the expense? Or is a carefully balanced, evidence-based strategy of minimal fungicide combined with targeted nutritional support a better path forward?

It's time to ask difficult questions and make well-informed decisions—your farm's resilience and profitability depend on it.

References:

• Araus, J. L., Slafer, G. A., Reynolds, M. P., & Royo, C. (2008). Plant breeding and drought in C3 cereals: what should we breed for? Annals of Botany, 101(5), 715-726.

• Calvo, P., Nelson, L., & Kloepper, J. W. (2014). Agricultural uses of plant biostimulants. Plant and Soil, 383(1-2), 3-41.

• Foulkes, M. J., Hawkesford, M. J., Barraclough, P. B., Holdsworth, M. J., Kerr, S., Kightley, S., & Shewry, P. R. (2011). Identifying traits to improve the nitrogen economy of wheat: recent advances and future prospects. Field Crops Research, 114(3), 329-342.

• Hawkesford, M. J. (2014). Reducing the reliance on nitrogen fertilizer for wheat production. Journal of Cereal Science, 59(3), 276-283.

• Khan, W., Rayirath, U. P., Subramanian, S., Jithesh, M. N., Rayorath, P., Hodges, D. M., ... & Prithiviraj, B. (2009). Seaweed extracts as biostimulants of plant growth and development. Journal of Plant Growth Regulation, 28(4), 386-399.