Slow Rusting of Wheat to Puccinia recondita

Seven cultivars of winter wheat were studied in field trials to determine their level of slow rusting ability towards brown rust. Cv. Bouquet was the most resistant, with greatly reduced infection levels, areas under die disease progress curve and infection rate compared with those measured on the control cv. Armadda. Cultivars Atou and Maris Freeman also showed evidence of slow rusting, but the responses of cultivars Waggoner and Flinor were not consistent in successive trials. Cv. Flanders appeared to be almost as susceptible as cv. Armada. The use of the Gompertz transformation of desease progress data for the calculation of apparent infection rates allowed better comparison of rates between cultivars than when the logistic transformation was used.