Having experienced the driest spring in over a century, dock populations in particular have thrived.

Dock plants' deep rooting ability allows them to reach moisture which grass cannot and their presence can significantly reduce nutrient value and palatability of silage.

Dave Gurney, Corteva Agriscience's Field Technical Manager for Grassland Crop Protection Products explains: "Docks compete with desirable forage species for light, water, and nutrients, often reduce the yield and quality of silage."

Once the dock population has reached 10% there is a direct correlation of 1% dock population causing a 1% reduction in grass DM yield. A simple way to assess dock population is to count the number of docks in an area of 5m x 7m. If there are 10 plants, then the population is 10%, and so on. It's a good idea to check five positions across a field in the shape of a W and take the average result.

Dave says: "A 10% infestation of docks will lead to a 10% reduction in grass DM yield. An effective dock management strategy is essential to maintain the productivity, palatability, and feed value of silage crops and of course to stop an existing presence getting worse each year."

Spraying a selective herbicide with good translocation properties to ensure effective root kill is a recommended course of action, but it is important to understand the best practice guidelines which will help achieve optimal effects.

"The timing of herbicide application is crucial," Dave says. "You want to see active growth and have docks which are ideally dinner plate size or less. If docks are hammered by dock beetle, ravaged by ramularia discase or have started to produce a flowering stem then control is less than what it should be."

The drier weather so far has caused docks to produce very little foliage and even the smallest of plants are going into the seed production growth stage, which will greatly reduce the amount of chemical translocated into the plant roots.

Dave says: "A spray between silage cuts is an ideal application time. Following rain across most of the country, docks are re-emerging after cutting."

With a typical cutting interval of around five weeks, a fast-acting herbicide is needed. It takes around three weeks for docks to grow to a suitable stage. This then leaves just two weeks for the chemical to be applied and for it to translocate to the roots of the docks.

Typically silage fields contain straight grass, without clover, so new fast-acting selective herbicide, ProGrass will resonate. It has been launched this year and comes with a short cutting interval of just seven days, making it ideal for use between silage cuts.

Dave says: "ProGrass offers excellent translocation properties, works quickly and, apart from controlling docks, also tackles other undesirable weeds such as buttercups, dandelions and nettles.

"ProClova XL is another new selective herbicide for this year, and is clover-safe. If white or red clover are present then this is your best option. It has an impressive weed spectrum which includes docks, buttercups, dandelions, hogweed and cow parsley."

ProClova XL is not as fast acting as ProGrass and requires a 21-day cutting interval following spraying. It favours warmer conditions where target weeds show active growth prior to seed heads being produced. 

Dave says: "We have written Best Practice Guides for ProGrass and ProClova XL. These give guidance on how to achieve the best level of weed control. These are available via the Corteva website, and also via a new QR code on the product labels too."

Dock control options for use on  grassland used for silage, hay or haylage