Roundup ProActive, (MAPP 17380) has an Extension of Authorisation for Minor Use, (EAMU) for Christmas Trees, and is one of very few products that can be used on this crop for inter-row and overall spraying.
Monsanto Technical Manager Manda Sansom said: "Roundup products contain glyphosate, which is active as a foliar spray on annual and perennial grasses, broad-leaved weeds and woody weeds, with speed of control increased in warm, humid weather when the weed is growing strongly.
"However, Roundup ProActive will still be effective in cool or cold conditions provided the herbicide dries on the leaf and the weed foliage is green and not senescing and there is no rain within four hours of application.. This makes it ideal for winter treatment ‘over the top’ whilst conifers are dormant, though the effect will be slower and can take up to a month to show."
Most Christmas trees have reasonable tolerance to sprays applied during the autumn and winter, but it is essential that the trees are healthy, fully dormant, with well waxed needles, with the period of application being between mid-October and the end of February, says Roundup.
Pines, Norway Spruce, Blue Spruce, Serbian Spruce and Nordman Fir can all be treated.
Roundup added that ‘over the top’ use is at the grower’s risk and should be used with care following professional advice.Sansom added: "The formulation of Roundup ProActive means that Christmas tree growers still have a highly effective weapon in their armoury against weed competition in their plantations, enabling them to continue to get the best from this valuable crop."