Raising awareness of impact from pesticide withdrawals
Scotland’ s grain and oil seed growers need to take a leaf out of the soft fruit and field vegetable sectors’ approach and place more emphasis on integrated p est manage - ment to extend the life of the shrinking armour y of pesticide sprays.
That was one of the takehome messages for Scotland’ s agricultural sector given at the first major conference organised by the country’ s recently set up Plant Health Centre.
Looking at the potential impacts arising from pesticide withdrawals on plant health, Dr Andy Evans of the SRUC’S crop and soils systems division said that those producing higher value crops had recognised the need to adopt a number of approaches to protect from pest sand diseases such as varietal resistance and the use of biological control methods.
However, he said that the whole industry needed to be aware of the threats to pesticides– as many of those growing commodity crops still tended to view the spray can as the first port of call to address such pressures.
Evans said that recent years had seen an increasing numb er of pro ducts taken off the market– either because the manufacturers couldn’t justify the expense of re-registering them or due to pressures applied by lobbying groups: “And with only a limited number of new pro ducts making it onto the market, it is inc redibly important that we adopt a range of me asures to ensure that the falling numb er of pro ducts available don’t succumb to a build up of resistance amongst pests and pathogens.”
As an example he said that the removal of neonicotinoi d seed dressings meant that farmers had to rely on pyrethroid sprays to control aphids – but a large proportion of grain aphids were now resistant to this spray, leading to an increase in the threat of aphid vectored diseases such as Barley Yellow Dwarf Virus in grain crops.
But he said that while the farming industry needed to be aware of the need to protect the effectiveness of the available chemicals, lobbyists and politicians needed to be aware of the repercussions of banning them :“While it maybe easy to decide to bend to public will and ban products, there are often severe considerable re per c ussions and even unintended consequences.”
Citing the ban on chlo - rot halo nil which comes into effect next year, he said the move was likely to place considerable pressures on other chemicals used to control septoria in wheat as mixtures were crucial to prevent the build up of resistant pathogens.
Other pressures for the sector were likely to evolve from changing weather patterns according to Dr Mike Rivington, climate change specialist with the James Hut ton Ins titute who told the conference that in the future UK crops, especially those in the south, were likely to face greater chances of drought and heat stress as well as new pest sand diseases.