Scale

Disease incidence %age

Description

0

0.0

Leaves free from leaf spot

1

0-5%

0-5 per cent leaf area infected and covered by spot, no spot on petiole and branches.

2

6-20%

6-20 per cent leaf area infected and covered by spot, some spots on petiole.

3

21-40%

21-40 per cent leaf area infected and covered by spot, spots also seen on petiole, branches.

4

41-70%

41-70 per cent leaf area infected and covered by spot, spots also seen on petiole, braches, stem.

5

>70%

>71 per cent leaf area infected and covered by spot, spots also seen on petiole, branch, stem, fruits.

Table 1: Disease rating scale for the assessment of Alternaria blight of tomato.