Optimization of field evaluation of resistance of sugar beet cultivars to cercospora leaf spot

Document Type : Scientific - Research

Authors

1 Tarbiat Modarres Univ. College of Agriculture, Iran

2 Sugar Beet Seed Institute, Iran

Abstract

To optimize the field evaluation of resistance to Cercospora leaf spot, 12 sugar beet cultivars were evaluated under field conditions in Gharakhil, Ghaemshahr at 15-days intervals. Measurements were carried out based on KWS 1-9 and Agronomia 1-5 scales. Disease severities were graded based on total plants per plot and also based on means of 5 randomly selected plants in each plot. Analysis of each recording date and also multivariate analysis of variance based on Lambda statistics indicated that measurements at each stage are not reliable for resistance evaluation and infection severity should be recorded during the growing season. So genotypes comparison should be done based on the disease trend during the season. Also, it seems that plot grading is as accurate method for measurement of infection as single plant grading. Therefore, it can be used to facilitate the evaluation of resistance.

Keywords