Abstract
The resistance of wheat to Puccinia striiformis f. sp. tritici was investigated. The durable resistance of Hybride de Bersée and that resistance controlled by the factor YR14, in cvs Solitaire and Wembley were studied at the second and sixth leaf stages, using a point inoculation technique. Both resistance types had significant effects at both leaf stages but the most marked effects were evident on adult plants. At both leaf stages there was a high correlation between colony, length and urediniospore prodction.