Experts warn Light Leaf Spot is increasing in oilseed

Spraying fungicide before the disease reaches the canopy of the crop. | File photo

The first opportunity for farmers to conquer light leaf spot (LLS) in oilseed rape crops is here and farmers are encouraged to take this opportunity to apply the proper fungicide to any crop that may be susceptible to LLS. 

Experts say it is especially important because winter weather was not strong enough to kill it this year.

“In the past week we’ve seen LLS in early drilled crops, which last had a spray in November. Crops sprayed in December will also be running out of protection, so with no threshold required for spraying crops before stem extension growers need to be thinking about taking action,” Dr. Faye Ritchie,an Agricultural Development and Advisory Service senior plant pathologist, said.

Attacking fields as soon as possible is vital to attacking LLS before it spreads to stem extension, which could signify a heavily infected crop. Farmers should be aware that seed varieties with high resistance ratings still have a chance of developing LLS, even though they will give more time to spray than varieties with less resistance.

The most important takeaway is to spray fungicide before the disease reaches the canopy of the crop.

If the disease gets into the canopy, farmers will only be able to protect new growth. The danger now is that even autumn treated crops could run out of steam ahead of stem extension. It looks like there could be plenty of the disease again this season and canopies could be at the mercy of rain and wind dispersed spores. 

"An application now with a potent LLS product such as prothioconazole would protect current growth, and could be topped up with a growth regulatory and LLS active such as tebuconazole at stem-extension,” Bayer’s Darren Adkins said.

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