The times they are a changin, went the song by Bob Dylan and they certainly are. The grass growth has slowed down in the garden so the mower is used a little less but we’ve been busy harvesting apples and pears and what a bumper crop they’ve been.
Unfortunately, there have also been some changes in our toolbox for growing beet and potatoes come about recently and they’re not so good. In most industries change seems to bring progress and things become easier and more efficient, but that does not seem to be happening in the world of crop protection, certainly within the EU anyway.
It has been mentioned before that the change in the EU’s attitude on risk and hazard will have a big effect on our armoury and it seemed for a while we were wrong as things seemed to stay around. But wow is that changing. It now appears that as everything comes up for review the default is to boot it out. This means that many of our tried and tested tools are not going to be available in the long-term.
In sugar beet, the Government has recently rejected the applications made by the British Beet Research Organisation for emergency authorisations of neonicotinoids as a seed treatment for use in sugar beet next year. So even though we have flonicamid recently approved for 2019, virus management will be more challenging going forward.
In potatoes, the loss of diquat, metam sodium and pymetrozine (all confirmed in the last few weeks) will be a major blow to potato production. It is probably fair to say we have been expecting it, a bit like the loss of linuron, but all of a sudden plans and practice need to change.
With linuron an excellent replacement in metobromuron was already available, but with diquat and metam true replacements do not really exist. Metam was a very useful tool in PCN management when the balance needed to be re-addressed where the overall management programme had been struggling to keep things at a suitable level.
With this loss there are no really effective ways of pulling high PCN numbers down rapidly. Now PCN will have to be managed on a much longer term and more holistic approach, utilising everything in the toolbox for this very troublesome pest.
The first thing to identify (even more important than ever) is to know your populations and one-hectare grid satellite mapping as recommend in the recently published AHDB guide will become a must.
Rotations going out to seven or eight years – while not popular for many reasons will be a big help – the utilisation of resistant varieties in the rotation is having a really dramatic effect and will be discussed at our Fen Potato Demo result day in November at Newmarket. New, more environmentally-friendly materials hopefully coming along (for example, fluopyram from Bayer) will be a great help, but the essence will have to be a more carefully planned, long-term approach.
With diquat we have had an excellent tool for stopping haulm growth quickly. Those that can remember acid will know of the worry we felt when that material disappeared but potato production went on. I think the same will happen with the loss of diquat, but again planning the approach to haulm destruction will be much more important.
So a product manufactured in Huddersfield will continue to be shipped to 80 different countries around the world but its use will not be permitted in the EU.
Haulm toppers have come long way in the last few years and these, combined with the other actives available such as pyraflufen-ethyl and carfentrazone-ethyl, will be effective at managing haulm growth in most situation. But not planting late bulking varieties like Markies last, chitting to bring crops forward, judicious nitrogen rates and maleic hydrazide may all have to be utilised to effectively manage haulm in some situations.