On his 95th birthday, he told VOA that the work to improve crop yields must continue.

VOA: standard.2009.09.16

Australia is a major food exporter, and if drought dramatically cuts yields, that could cause global prices for grain,meat and other foods to rise.

VOA: standard.2009.09.03

Too little means lower yields and lower profits. Too much wastes money and causes pollution.

VOA: standard.2010.07.28