Dow AgroSciences is introducing a new, improved formulation of its broad-spectrum herbicide Pastor called Pastor®Pro. It will join Doxstar®Pro and Grazon®Pro in the company’s portfolio of grassland products.
Vegetable, allium and nursery crop growers have been plagued in the last few years by the loss of crop protection actives, either as more products are revoked or go through re-registration and lose crops. But one manufacturer has been busy adding to their recommendations and supporting and encouraging Extension of Authorisation for Minor Uses (EAMU’s) for their chemistry. “We get a lot of queries from growers on our Hotline about what they can use on their vegetables and onion crops. One of our classic active ingredients clopyralid continues to be an important herbicide for these specialist growers and each year additional crops are added or recommendations altered to make them even better,” says Dilwyn Harris, Principal Biologist for Dow AgroSciences.
The mild winter and kind spring weather means many soils in the south and west have now reached 5-6°C at 10cm depth. This has triggered both grass and broad-leaved weed growth and the competition for light, space and nutrients is under way.
“As day length increases, every day soil temperatures reach 5oC or more, root and shoot growth starts,” says Andy Bailey, grassland specialist for Dow AgroSciences. “Soil processes also start to kick in as bacteria start to break down organic matter producing nitrogen in plant-available form, which also helps stimulate new growth.
“However, weeds do not start all growing at the same time. Buttercups and dandelions are the first to get going. Bad infestations may need spraying with a translocated herbicide in the next two to three weeks, when rosettes of actively growing, fresh green leaves can be seen,” Mr. Bailey advises.
“Waiting until the field is a carpet of yellow in April is too late and spraying then will be less effective. If docks are also a problem, farmers should not be tempted to spray for both at the same time – when the docks are at the ideal stage for treating, buttercups and dandelions will be too far advanced.
“Broad-spectrum herbicides such as Pastor on silage ground and Forefront T on land grazed by cattle and sheep, are good options for early applications to catch both buttercups and dandelions.”
Ragwort will be the next weed to start growing, followed by docks and thistles.
“In the South West, docks are just bursting into life, with new leaves springing out of the centre of established plants and seedling docks pushing up through the sward. But it is likely to be another month before they are ready for spraying – by then they should be at the rosette stage and at least 25cm across or high.”
As the warmer weather approaches and fertiliser applications are made, the spray window for the control of cleavers in winter oilseed rape opens and growers need to be ready to apply their post-emergence herbicide. Galera (clopyralid and picloram) is the main spring-applied herbicide due to its high level of performance and its weed spectrum which includes cleavers, mayweeds, creeping thistles and sow-thistle. It must be applied before the latest date of application which is when flower buds are visible above the crop canopy.