KICKING THE HABIT: PESTICIDES
Given half a chance, microscopic pathogens will eat our crops for breakfast, lunch and dinner - causing diseases which lower yields, reduce harvest quality or even contaminate the crop with harmful toxins. Short generation times mean they can adapt quickly to our defences, whilst international trade, crop monocultures, and climate change are helping them spread rapidly around the globe.
Weeds represent a growing threat to crop yields and global food security. Although the widespread use and efficacy of herbicides has meant that large yield losses from weeds have been largely avoided since the introduction of chemical weed control in the 1960s, widespread evolution of resistance to herbicides is leading to increasing yield losses from weeds in intensively managed cropping systems. Epidemics of herbicide-resistant species are now becoming increasingly common including black-grass in northwest Europe, Palmer pigweed in southern and central United States, and Wimmera ryegrass in Australia.
Insects are a huge problem for food production, either through direct feeding damage to plants or by the crops diseases they spread. But insects also play a vital role in the functioning of terrestrial ecosystems, and they are in steep decline. Balancing crop and insect protection is tricky to achieve - but mitigating against the overuse of insecticides will reverse population declines, thereby protecting the important roles that insects play in our farmed landscape, such as pollination, decomposition, and pest regulation.
STRAIGHT FROM THE EXPERTS
Whether driven by politicians, consumers, or pests’ evolving resistance, it’s clear our approach to crop protection needs to change. There is no silver bullet, but a range of methods that when used together, could significantly reduce our pesticide use.
By utilising technology, such as fungal spore monitors or real-time insect surveillance data, farmers could limit spraying to only when it is needed. The development of crops better able to withstand pests and diseases will also help, as will a better understanding of how we can harness nature to control outbreaks of pests and weeds. More diverse rotations to lengthen the amount of time between the same crop, combined with improved soil health, will be needed to reduce land used for food production and the carbon footprint of farming, while helping maintain a secure food supply.