Killing weeds in new reseeds should now be a priority

Many pastures that were reseeded in the early summer are now in urgent need of weed control.

Perennial weeds such as chickweed, docks, thistles and buttercups are now dominant in these new pastures and it is vital to control them as soon as possible. Otherwise, they will continue to flourish and will smother out the new grass.

According to Chris Maughan, technical manager with Whelehan Crop Protection, chickweed is a serious problem in many recently sown swards.

“If not controlled early, chickweed will severely damage the new sward. It is equally important to control docks at the seedling stage, before the large taproots have a chance to develop,” he advised.

While topping may be effective in controlling annual weeds such as fat hen, fumitory, knotgrass and charlock, it will have little effect on the perennial weeds. The use of an effective herbicide is the best option.

Envy the perfect choice

Envy, the herbicide introduced three years ago to the Irish market by Corteva Agriscience, is the perfect choice for reseeded pastures.

Containing the two potent active ingredients fluroxypyr and florasulam, it is effective on a wide range of weeds including chickweed, docks, dandelions, buttercups, plantains, mayweed, charlock, fumitory and dead nettle.

It should be applied on reseeded pastures at 1L/ha in 200L of water. Where chickweed or docks are large, the application rate should be increased to 1.5L/ha.

Envy works well in cooler conditions and is licensed to be applied up to November 30. This gives great flexibility in the timing of application and also makes it an ideal post-emergent herbicide for autumn-sown reseeds.

Use Pastor®Trio on thistles

Pastor®Trio, another recently introduced Corteva Agriscience herbicide, is also highly effective on reseeded pastures.

It contains three active ingredients, florasulam, fluroxypyr and clopyralid. As well as being effective on the same range of weeds as Envy, it also controls thistles.

“Therefore, where thistles are among the target weeds in reseeded pastures, Pastor®Trio should be the herbicide of choice. It should be applied on reseeded pastures at 1L/ha in 200L of water,” advised Chris Maughan.

Docks, chickweed and other weeds are prominent in recently harvested wholecrop silage, undersown with grass

Dealing with weeds in undersown pastures

With wholecrop silage crops undersown with grass now being harvested, close attention should be given to weed control to ensure optimum development of the new sward.

Because of the limited number of herbicides available for treating these crops, many would not have received any treatment for weeds. As a result, the presence of docks, chickweed and thistles is common. Also, because of the recent wet spell many swards are infested with creeping buttercup.

An application of Envy or Pastor®Trio, depending on the weeds present, will pay handsomely in the growth and development of productive grass.

Grazon®Pro is the perfect spot treatment for briars and other weeds at fences and field boundaries

Grazon®Pro is the perfect spot treatment for weeds

Grazon®Pro is the proven herbicide for spot treating weeds at fences and field boundaries. It is also an ideal spot treatment where weed infestations across fields and paddocks are 5% or less.

Containing two powerful root killing ingredients – triclopyr and clopyralid – it is powerful on a wide range of weeds including nettles, thistles, docks, buttercups, brambles, gorse, cow parsley and hogweed.

It should be applied at a rate of 60ml in 10L of water using a conventional knapsack sprayer, a quadbike sprayer or a suitable lance on a tractor mounted sprayer. Best control is achieved where weeds are sprayed before the flowering stage. Keep animals off treated areas for seven days.

Forefront®T – the gold standard for grazing pastures

When it comes to choosing the perfect broad spectrum weed killer for grazing pastures, Forefront®T is the gold standard.

Imbued with the most advanced chemistry in weed control technology, Forefront®T has become the product of choice for a growing number of farmers seeking to clean pastures of a wide spectrum of weeds.

It contains two chemicals, aminopyralid and triclopyr. This powerful combination makes it the perfect choice for docks, thistles and nettles as well as a range of other weeds such as buttercups, chickweed and dandelions. It is also the product of choice for ragwort.

As with all translocated herbicides, best results are achieved from applying Forefront®T when weeds are actively growing and before they flower.

Silage swards that were cut in recent weeks where weeds were present, now is the perfect time to clean up the aftergrass with an application of Forefront®T.

In permanent pasture at this stage in the season, best results will be achieved from topping the pasture and applying Forefront®T after three to four weeks regrowth, when the weeds should have reached the ideal stage for an effective kill.

Apply Forefront®T as a single application at 2L/ha in a minimum 200L water/ha. Keep stock off the pasture for seven days after spraying. If ragwort is among the target weeds, keep stock off until the ragwort has died away and disappeared.

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