CropWorld 2010: Farmers need alternatives to chemical crop protection

Declining numbers of chemical crop protection products meant the industry should be looking for alternative options, said Toby Bruce, senior research scientist for Rothamsted Research.

"We need to see what other tools are out there."

Resistant varieties, inducing plants natural defences and harnessing natural enemies were all effective solutions, but they needed to be used in combination, he said. "None of them will be effective enough on their own."

Varieties with resistance to specific pests were playing an important role, but a broader spectrum of resistance was needed, said Dr Bruce. For example, orange wheat blossom midge resistance had been successfully bred into a number of wheat varieties, but could still be crippled by yellow rust.

"In the field, crops are exposed to several difference pests so multiple resistances are needed."

But getting these traits into commercial crops through conventional breeding was time consuming, he noted. "GM technology could speed this process up and I would say it is foolish to ignore this process."

Methods of activating plants natural defences were also making progress, he said. Scientists at Rothamsted Research had discovered the gene responsible for producing a pheromone which caused aphids to disperse. The gene had been put into wheat and was waiting to be entered into trials.

Field margins that helped preserve natural enemies to crop pests were another useful tool, but they needed careful management to ensure the insects ventured out of the margin to interact with the pest, he added.

Careful monitoring of pest and disease pressure was the final part of the puzzle to make sure these technologies were used to best effect, he concluded.