Given current conditions, the grass is still growing rapidly with growth rates still high and over 80kg dry matter (DM)/ha, but this means that weeds are also thriving.
Weeds can be a serious headache at this time of year, as they emerge in the heat a couple of weeks early and thrive in the current humidity, making them difficult to control.
Wet and windy conditions mean there aren’t too many sprinklers on the go.
But as the grass grows far beyond demand, there is a lot of mulch used to correct the quality and thus control weeds.
However, before starting weed control, it is important to identify which weeds are a problem in order to develop a plan to deal with them.
Topping
There’s always an argument that a topping isn’t necessary if Grassland management It’s up to standard, but actually it can still be a useful exercise.
37% of farms registering grass in PastureBase still exceed the target, entering pastures with a pre-grazing yield of 1,789 kg DM/ha.
These farms must remove excess bales from pastures, but topping can also help correct grass quality rather than constantly catching up.
In addition, pastures help prevent the spread of weeds by making their growth less vigorous and reducing their competitive ability in the pasture.
Mulching is most effective in controlling weeds when you remove the flower head and upper leaves in dense areas of thistles, thorns and nettles before the bud opens.
It is recommended to cover the field again a month after the first cover to prevent weeds from flowering.
The fear with mulching is that it will affect the grass regrowth rate if pastures are not mulched immediately after grazing, as pre-grazing cover for the next cycle may be affected.
Weed control
Realistically, top dressing will control weeds in the short term, and may work in the long term if you are persistent over the coming years, but growers often have to use some herbicide to get complete control.
It is important to know your fertility status, because it will indicate whether or not your soil needs lime, phosphorus (P) or potassium (K), which will allow you to grow more grass, limiting the space devoted to weeds.
Controlling weeds at this time of year is vital because they are in the rosette stage (150-200mm in diameter), which is the easiest stage to kill weeds.
Best practice is to spray the docks shortly after reseeding, which will prevent them from establishing due to farm competition. Reseeding established seed will also reduce and suppress weeds.
Thistles should also be sprayed now, because they will now begin to form galls, branch off, and cover the grass, which will kill what is underneath.
The products used to target weeds are not cheap, so application must be precise and accurate to get the best results.
To ensure accurate spraying, it is important to read the product label carefully to ensure you are spraying at the correct rate.
Spraying tips:
- Make sure the product is suitable for killing weeds;
- Read the label carefully, adhering to buffer zones and prices;
- Keep a record of the product used;
- Spray in appropriate conditions – not windy or wet;
- Wear protective equipment;
- Wash spray equipment after use;
- Adhere to the recommended time between spraying and grazing or cutting silage (about seven days later);
- In the case of ragwort, animals should not be allowed in until the grasses have become completely spoiled and unpalatable.
There are a few product options for controlling docks in your clover beds; However, there are limited treatment options for chickweed, nettle, thistle, or dandelion.
If clover is present on your land, you should choose a clover-safe product, which rules out many conventional products. If seeds and stems are present, the weed should be mulched first and sprayed after two weeks.
Farmers should target non-alfalfa pastures first and get the weeds completely under control and then look to plant alfalfa in these pastures next April or May.
Controlling weeds before clover is established will prevent further problems in the future.
Controlling weeds in your pastures this summer will increase grass yields, improve silage quality, increase grass utilization, and eliminate any health risks to livestock caused by certain weeds.
