Tobacco

Nicotiana tabacum

1. Identification and origin

Tobacco (Nicotiana tabacum L.) is an annual herbaceous species of the Solanaceae family, cultivated mainly for its leaves, used in the tobacco industry. The species results from natural hybridisation between Nicotiana sylvestris Speg. & Comes and Nicotiana tomentosiformis Goodsp., which occurred in South America. Domestication and spread occurred initially among the indigenous peoples of the Americas, being later disseminated globally after the 16th century.

2. Economic importance

Tobacco is a crop of high economic value in several countries, especially for the production of cigarettes, cigars, pipe tobacco and industrial products derived from nicotine. The crop generates intensive employment in manual operations (transplanting, harvesting, curing). In some agricultural systems, it is integrated into rotations with food crops, although it has high requirements in fertility and labour.

3. Botanical characterisation

Tobacco is an annual plant, 1–2 m tall, with an erect stem and large leaves, ovate to elliptical, alternate, entire and frequently sessile. The flowers are tubular, pink to reddish, gathered in terminal panicles. The fruit is a capsule containing numerous small seeds. The root system is deep and branched, allowing good exploration of the soil. The leaves accumulate alkaloids, mainly nicotine, synthesised in the roots and translocated to the aerial part.

4. Soil and climate requirements

Tobacco adapts to warm and moderately humid climates, with optimum temperatures between 20 and 30 °C. It is sensitive to frost and strong winds. It prefers light to sandy-loam soils, well drained, with a pH between 5.5 and 6.5. Excessively fertile soils or those rich in nitrogen reduce leaf quality. The crop requires good water availability, but is sensitive to waterlogging. Post-harvest curing (air, barn, fire or sun) is decisive for the final quality.

5. Main pests

• Peach aphid (Myzus persicae) — sap sucking and transmission of viral diseases
• Whitefly (Bemisia tabaci) — sap sucking and virus transmission
• Thrips (Thrips tabaci) — damage to young leaves and virus transmission
• Caterpillars (Helicoverpa armigera, Spodoptera littoralis) — perforations and defoliation
• Root-knot nematodes (Meloidogyne spp.) — root galls and reduction of vigour

6. Main diseases

• Tobacco mosaic (TMV, Tobacco mosaic virus) — mosaics, deformations and reduction of production
• Bacterial wilt (Ralstonia solanacearum) — irreversible wilting and death of plants
• Black shank (Phytophthora nicotianae) — root necrosis and death of seedlings
• Powdery mildew (Golovinomyces cichoracearum) — white coating and reduction of photosynthesis
• Alternaria leaf spot (Alternaria alternata, A. longipes) — leaf spots and necrosis
• Root rots (Rhizoctonia solani, Fusarium spp.) — damping-off and decline

7. General crop management

Tobacco management requires the selection of cultivars suited to the type of curing and the final market. Crop rotation is essential to reduce the pressure of soil diseases and nematodes. Fertilisation must be balanced, avoiding an excess of nitrogen that harms leaf quality. The monitoring of aphids, whitefly and thrips is critical due to the risk of viral diseases. Weed control in the early stages is decisive for crop establishment. Harvesting is carried out leaf by leaf, in several passes, followed by curing appropriate to the type of tobacco produced.

Bibliographic references

• EPPO Global Database – Nicotiana tabacum
• CABI – Crop Protection Compendium – Nicotiana tabacum
• Davis, D. L., & Nielsen, M. T. (1999). Tobacco: Production, Chemistry and Technology. Blackwell Science.
• Sisson, V. A., et al. (2019). Advances in tobacco breeding. Crop Science, 59, 1–14.
• Wang, H., et al. (2021). Genetic improvement and molecular biology of tobacco. Plant Biotechnology Journal, 19, 2151–2167.