| |
Conditions are now right for post-emergence residuals in oilseed rape
Date added: 30/11/09 |
Weather conditions are just right for applying post-emergence residual herbicides in winter oilseed rape, but every care must be taken to avoid any risk of these herbicides getting into water, says ProCam’s Technical Director, Dr. David Ellerton.
“Soil temperatures are now lower, around 8-10°C and are declining. Cold soils slow down weed growth and so grass weeds are less likely to outgrow any herbicide treatment. Cold soils also reduce the rate of microbial breakdown of the residual herbicides, thereby increasing their persistency so that weed flushes are controlled,” he says.
Moisture levels are just right too - not waterlogged or saturated but not too dry either - and this means that the herbicides can be redistributed into the rooting zone of the weeds, where they can be taken up more effectively.
“Applications of residual herbicides such as propyzamide (such as Kerb or Setanta) or carbetamide (Crawler) in winter oilseed rape should be underway. Usually applications made in November and December offer the best results, but if you want to improve that consistency then add in a contact graminicide such as Pilot Ultra (quizalofop-p-ethyl).”
But even if timing is right with regard to crop and weed stages and weather conditions, growers must avoid any risks of water pollution, David Ellerton points out.
“We have all been trained in how to avoid this risk and there has been excellent information issued from the key manufacturers such as Dow AgroSciences and Makhteshim, as well as the many statutory bodies.
“Tactics such as making sure that you leave a big enough buffer zone and avoiding any risk of run-off are key. But above all, if it is too wet or if there is any risk to water, then just don’t spray and wait until conditions are appropriate.”
When the application window is wide open, it is all too easy to just get on with the job and some maybe tempted to cut corners, he says.
“There are potentially serious implications of getting it wrong this autumn/winter. If we fail to avoid water pollution, we run the real risk of losing these valuable herbicides all together.
“Both propyzamide and carbetamide are not used in cereals and offer important alternative herbicide groups to incorporate into an effective grass-weed control programme. It is vital that they are used carefully so that they can be retained in the future and the on-going battle against black-grass and other grass-weeds.”
Ends
PRM226
30th November 2009
For further information please contact Dr. David Ellerton, ProCam Ltd., Royston, Herts. Telephone: 01763 261592
Issued by Philip Hainey, Proterra Ltd., Stamford, Lincs. Telephone: 01780 756299 |
|
