Stripe rust spray critical

Press, 4 March 1983, Page 20

Stripe rust spray critical

A decision not to spray again for stripe rust on his plot might have cost Oxford farmer Mr Hugh Horn first place in the ICI-Tasman Wheat 82 competition, according to Dr , Warwick Scott, senior lecturer in plant science at Lincoln College. Instead, Mr Hom came second in the yield competition, though he won the grain quality competition. Dr Scott, who is on the Wheat 82 organising committee, said that if stripe rust had been controlled in Mr Hom’s plot, grains would have grown to about 44 mg to give a total plot yield of 5.89 tonnes a hectare — an increase of half a tonne a hectare over his result.

“The increased yield would have been more than enough to cover the cost of spraying, and enough to win the competition,” he said. “In all the Rongotea plots, except Mr Hom’s, the grains grew about 4-5 mg larger than predicted, probably because December was wetter and cooler than average. “His grains grew no larger than the predicted 40 mg, and a possible explanation is that he did not control stripe rust during grain filling.”