Wheat ‘most effective’ when cool

He proposed Australian croppers were growing wheat at the wrong time of the year - a suggestion that drew laughter among the SANTFA conference audience.

"Wheat growth is most effective at temperatures of 18C degrees during the day, and 10C at night," he said.

"Any temperature more than 18C, and wheat respiration and development is too fast, and you don't get maximum yield.

"For every day that it is more than 25C during grain-fill in wheat, you lose about 65 kilograms a hectare a day in yield potential.

"So if you can move that planting date, or figure out how to get your heading date when your temperature stays in that 10-18-degree zone, you will get the highest wheat yields."

Peter, also known as 'Wheat Pete' or 'Peter No-Till', is a zero-till cropper from the Great Lakes region of Canada, where they grow corn, soyabeans, wheat and alfalfa.

He says corn yields can get up to 15 tonnes a hectare, while wheat has recorded up to 9.4t/ha.

Their rainfall is about 900 millimetres a year, but averages about 75mm a month, with four of those months under snow.

"So in usable precipitation – it is not much different to areas of Australia," he said.

"In Australia, you may only get 450mm, but 90 per cent of that is usable.

"Even with 900mm, Canada is now starting to run short during grain-fill, which we didn't expect.

"It's a concern when our yields have gone up so much."

In 2013, Mr Johnson received the President's Technology Award from the Oxford County Federation of Agriculture and in 1997 was awarded the TR Hilliard Agricultural Extension Award.