Currently, an investigation is being conducted into three suspicious populations of Italian ryegrass in the UK. Results are expected by the end of this year. Italian ryegrass is currently the only weed in the country with suspicious presence. Extensive testing of foxtail and 166 samples of bonfire grass was conducted in 2023. However, populations causing concern were not found.
The herbicide glyphosate is an essential tool for British farmers. However, resistance to it raises serious concerns. John Cassans, chief weed science consultant at the agricultural consulting company ADAS, emphasizes that while weed resistance on one farm is not currently a widespread problem, attention must be paid to the prospect. Research shows that Italian ryegrass and annual ryegrass Lolium rigidum have a high risk of developing resistance to glyphosate.
To reduce the risk of resistance, farmers should take several key measures. Firstly, using a sufficient dose of glyphosate to destroy target weeds is essential. It is important to choose the right dosage depending on the size and types of weeds. Secondly, correct application technique ensures the necessary dose is achieved. This involves selecting the appropriate nozzle, controlling the speed of the machinery, and ensuring water quality. Additionally, it is important to apply glyphosate to actively growing weeds.
In the case of unsuccessful control with glyphosate, the reasons should be thoroughly investigated. Often, inefficiency is related to errors in glyphosate application or poor application conditions. If the reasons are not obvious, seeking additional consultation and possibly conducting a resistance test is advisable.
It is important to avoid repeated glyphosate applications to weeds that survived after the first treatment. Instead, using other chemical or non-chemical control methods, such as mechanical weeding, is recommended. Persistent control measures on all farms and effective measures to prevent seed reproduction and movement will help maintain the effectiveness of glyphosate at a high level.
Bayer, a leading producer of glyphosate-based herbicides, also urges farmers to reduce the risk of resistance. Bayer is confident that glyphosate will remain a key tool in weed management on farms. Applying the right methods, controlling the application rate, analyzing effectiveness, and maintaining equipment will help improve weed control and reduce the likelihood of resistance.