After a wet spring, the recent good weather has given many farmers the opportunity to reseed some of their poor performing paddocks.
To ensure that your reseeding is successful, early management of the sward is critical.
Failure to control weeds within a reseeded sward will lead to issues in the future; the two most important weeds to control within a reseed are dock and chickweed.
The best time to control these weeds is when the plant is at the two to three leaf stage; other weeds that may cause problems within a sward include: fat hen, charlock, redshank and mayweed.
The most effective way of controlling docks and chickweed is through the application of a herbicide – this should be done before the first grazing takes place to obtain the best results.
Docks are a persistence weed, with seeds being able to survive in undisturbed soil for up to 50 years – meaning land that previously did not have docks could now have them.
If this has been an issue in your reseed – your best chance to control docks is when the dock is at the seedling stage; once they past this stage they are harder to get under control.
When choosing a herbicide for the control of docks, the presence of white clover within the sward must be considered, as some herbicides can damage white clover if it is not fully developed.
Similarly controlling chickweed within a reseed can be difficult, with chickweed being harder to control in fields that are not grazed regularly – such as fields used for silage.
To ensure that your reseed is successful and weed are kept under control within the sward selecting the correct herbicide is important.
When should I graze?
After reseeding the question many farmers will ask is – when should I graze the reseeded sward?
The timing of the first grazing can have a major impact on the production of the new sward.
The first grazing should be ideally be completed when conditions are dry – this is to avoid damage.
Grazing at the right stage will allow light to penetrate the root of the sward encouraging tillering of the new sward.
Teagasc recommends grazing when the sward can withstand the ‘pull test’ and when there is a cover of between 700kg /DM/ha and 1,000kg /DM/ha.
Subsequent grazing should have a target cover of between 1,000kg DM/ha and 1,400kg DM/ha, depending on stocking rate and rotation length.
If possible the harvesting of silage should be avoided for the first year, as this can lead to reduced growth rates and hamper the amount of tillering carry out by the sward.