Abstract
Spore production by A. candida on B. campestris was highly correlated (r = 0.93) with a visual white rust interaction phenotype (IP) rating scale. Plants were rated 0-9 according to the amount of leaf necrosis or area covered by white rust pustules. Means of spore production on plants rated as 1, 3, 5 and 7 were significantly different from each other (P = 0.05). These results support the use of a visual scale in selecting for components of partial resistance to the white rust disease.