Growers have been asking the Dow AgroSciences’ Hotline whether the herbicide Galera (clopyralid + picloram) can be used this autumn where broad-leaved weeds have grown through pre-emergence herbicides which were applied during the very dry September. Sarah Hurry of Dow AgroSciences advises them that the answer is Yes.
“Existing stock of Galera sold under the previous approval (MAPP No 11961) can be used this autumn or in the spring. It needs to be used by the 30 September 2015. So it is quite OK to use Galera now.”
“It appears that broad-leaved weeds such as cleavers, mayweeds, groundsel, thistles and corn marigold may have come through the pre-ems, due to the exceptionally dry conditions this autumn - unsurprising as this September was the driest since 1910,” she says.
Sarah remarks that most rape crops are already beyond the earliest application time for Galera which is 4 true leaves of the crop. “Galera works best when both crop and weeds are growing well. In terms of target weeds, it has label recommendations for the control of cleavers, scented mayweed and scentless mayweed. In our experience, and supported by reports from growers and agronomists, good activity can also be expected on coltsfoot, cornflower, creeping thistle, fool’s parsley, fumitory, groundsel, sow-thistle, volunteer beans, volunteer peas and volunteer sugar beet as well as some spring germinators such as black bindweed and redshank. It will deliver good activity on all these weeds providing the temperature is above 6 ºC and rising.”
Sarah mentions that both ASTROKerb and Kerb Flo 500 will also control a range of broad-leaved weeds, but are mainly targeted at black-grass and other grass-weeds, and would normally be applied from early November when soil temperatures are around 10ºC and falling and when soils are moist.
“ASTROKerb delivers the same weed spectrum as Kerb Flo 500 with the addition of mayweed species and common poppy. We would also expect some activity on sow-thistle and groundsel,” she says.
