No point in paying over €300 an acre for reseeding if post-management is neglected

IF you have gone to the trouble and expense of reseeding (up to €320/acre), every effort is needed to ensure that you have a dense, leafy clover/grass sward available for your stock next spring. Post-emergence management of ryegrass and clover seedlings, along with weed control, are both as important as sowing the new ley itself – this care is very much the same whether clover is present or not. 

Post Emergence Management: The aim of reseeding is to allow grass and clover seedlings establish and develop after sowing. Allowing the grass to get too high will shade out the clover seedlings. Grass seedlings will not tiller out in this situation either. Best suggested practice is to first lightly graze the sward with sheep or weanlings before closing for the winter.

This will encourage the young grass plants to tiller out and the sward to thicken up. A light grazing also exposes emerging clover to light and enables it to develop and grow. If possible, delay any cutting of silage for twelve months to allow grass tillering and clover establishment. 

Some light grazing of the reseeded sward may need to be carried out over the winter months to prevent grass from getting too high. A bag of CAN/acre can be applied after 15th January next year with a tight first grazing being undertaken. Avoid poaching of reseeded swards when grazing. Remove stock during periods of heavy rainfall.

 Weed Control: The most cost effective method of weed control is to use a post emergence herbicide.  The best time to control weeds is at the four leaf stage in weed seedlings. By using a clover safe post emergence spray, seedling weeds can be destroyed before they develop and establish root stocks. Established weeds can seriously reduce the yield potential and economic lifetime of the reseeded sward.

The post emergence spray should be applied approximately six weeks after establishment just before the first grazing takes place. Seedling docks and thistles along with tillage weeds such as Redshank, Rat Hen, Charlock and Chickweed can be controlled in newly established swards by using Legumex DB, Alistell, Underclear/Undersown and Mastercrop Undersown.

These sprays will not damage seedling clover after the trifoliate leaf stage; and they will not affect young grass shoots. Alistell and Underclear would be the products of choice if chickweed is present.

For non clover reseed swards, herbicide sprays such as Pastor, Nintex, Dockstar etc can be used. Check with local Agri-Merchants for other herbicide sprays that could be used. These sprays will wipe out any seedling clover present in the new ley. They will control most emerging perennial weeds and tillage weeds.

Again, they should be applied to new swards 6 to 8 weeks post sowing where needed. Follow the manufacturer’s advice on the information leaflet on each pack/container of spray in relation to rates/ha and dilution rates. Ensure to keep the prescribed Cross Compliance records for any chemical spray used.

Pest Control: Pests such as Leatherjackets, Wireworms and Frit flies should not be a problem in grass seedlings if the seedbed and field margins were free of trash and decaying organic material at the time of sowing. This deprives these pests of the environment on which they thrive. Slugs and leatherjackets could be a problem in heavier soils. If infestation is a serious problem, consult your local Teagasc Adviser/Agricultural Consultant or Agri-Merchants on what pesticide to use.

*Anthony O’Connor is a drystock adviser with Teagasc, Athenry. Comments to anthony.oconnor@teagasc.ie