GB/T 23222-2008Grade and investigation method of tobacco diseases and insect pests (English PDF)

2.1

Since suffering the impact against biological agents or other non-pathogenic organisms, growth and metabolism of tobacco is disturbed or damaged, leading to

Reduce the yield and value, quality deterioration, and even partial or whole phenomenon of death.

2.2

Direct feeding of tobacco or tobacco spread of disease and economic losses caused by insects or mollusks tobacco production.

2.3

The degree of disease occurrence of tobacco on the population level, based on the statistics of morbidity and disease severity combined, with the onset of numerical representation degree.

2.4

Plant or degree of damage roots, stems, leaves and other parts.

2.5

The degree of occurrence of tobacco aphid population level, the number of aphids is a statistical survey sample size and level combination, expressed numerically

The degree of occurrence of aphids.

3.1 Tobacco roots Diseases

3.1.1 blackleg

3.1.1.1 disease severity rating

In units of strain classification survey.

0. whole plant disease.

Level 1. stem lesion does not exceed the girth of one third, or one-third less blade wilting.

Level 3. stem lesion surrounded girth half to one-third, or one-third to one-half blade mild wilting, or lower part of the minority

Leaf lesions appear.

Level 5. stem lesion more than one-half of girth, but does not surround the entire girth, or one-half to two-thirds of the blade wilting.

7. All stem lesion surrounded girth, or more than two-thirds of the blade wilting.