The relationship between rain and light leaf spot revealed

If you grow oilseed rape, you might be dreading the wet weather more than the average person.

After all, it’s well known to be one of the biggest influences on light leaf spot, which is why you’re probably as knowledgeable as a meteorologist when it comes to the forecast.

But what if we told you that rain doesn’t necessarily equal the presence of light leaf spot?

Don’t believe us? Check out the graph below from trials of SwiftDetect: the only crop disease test on the market that will give you pharmaceutical-grade accuracy and 1 business day results.

This data came from the Nottingham trial site, where SwiftDetect was used on four oilseed rape varieties.

The SwiftDetect score, which measures the level of pathogen DNA present in the sample, has been plotted against rainfall. The higher the SwiftDetect score, the more disease is present in the crop.

© Swiftdetect by Microgenetics

As you can see:

• There is a positive correlation between rainfall and light leaf spot detection: especially for varieties 2-4, light leaf spot detection increases along with rainfall, confirming there is a relationship
• However, this isn’t always the case: despite heavy rainfall last October through to January, some varieties in the trial had no light leaf spot present at all whereas others did exhibit a drastic increase in disease levels, suggesting rainfall doesn’t guarantee disease. Instead, multiple factors such as variety should be considered
• There is a clear varietal difference: despite trialled crops all having the same resistance rating of 6, the level of disease detected varied considerably

If you were one of the lucky ones growing variety 1, which remained unaffected by light leaf spot during the wet weather, how much fungicide could you have saved if you tested your latent disease levels?

This insight could have helped you to prevent fungicide waste and potentially save money at no compromise to yield.

Alternatively, you may have been growing variety 2, where light leaf spot exploded. In this instance, you could have taken a proactive approach and ensured your dose rate was right to protect your crop.

As the wet weather approaches this season, make confident fungicide decisions with insight from SwiftDetect, who are leading the way in rapid molecular testing of crop disease.

How it works

Simply order online and post 10 leaves to Microgenetics, who developed SwiftDetect, for testing.

The SwiftDetect team use a uniquely sensitive method, capable of detecting down to a single pathogen cell, to quantify disease levels. They’ll send you results by email within 1 business day. You or your Agronomist can then use these results to make informed fungicide decisions.

What SwiftDetect customers say

In a 2021 survey, 100% of customers asked said they were happy with their SwiftDetect results, with 94% agreeing they’d use the test again.  

One happy customer was Robin Aird, who wrote an article stating: “The day before spraying we did another test with SwiftDetect, which turned the sample around in less than a day. This showed a little bit of disease but gave me the confidence to save more than £4,000.”

This year, SwiftDetect for wheat made headlines again, having helped Indigro Agronomist Damian Mcauley save a customer £1,600: “On one of our client’s farms, we tested for Septoria at pre-T1 (leaf 3) stage.

One end of the farm was reported to be high risk and the other end low risk. We, therefore, tailored the inputs accordingly and pulled back fungicide rates by roughly 10% on 400 hectares of wheat, making a £1,600 cost-saving,”

Want to give SwiftDetect for light leaf spot a go? Learn more or order SwiftDetect here.