TOBACCO: Bacterial and Viral Diseases

Abstract

Tobacco is a high value industrial crop, playing an important role in India’s agricultural economy. Tobacco is cultivated in fifteen states of India producing 760 M kg of cured leaf from an area of 0.42 M ha. Several bacterial and viral diseases adversely impact tobacco production and quality. The tropical and subtropical conditions in the country besides imminent climate change effects are congenial for further escalation of their incidence and resultant losses. The major bacterial diseases observed in India are bacterial leaf spot, angular leaf spot, bacterial wilt and hollow stalk. They are not a severe menace in all the tobacco growing regions and are endemic to certain locations. Incidence of viruses and damage accrued to them are increasing of late. They are significant threats to quality tobacco production and are of great economic importance particularly tobacco mosaic virus, leaf curl virus, cucumber mosaic virus, etc. Tobacco mosaic virus (TMV) has been studied for almost a century and has wide applications in medicine, pharmaceutics, nanotechnology etc., but the development of resistant varieties is the only solution to manage it on tobacco. The spread of its vector can be managed by utilization of either natural resistance or engineered virus-resistant plants and efficient management of insect vectors. Engineered plants, expressing RNA-silencing nucleotides, are becoming increasingly useful and are likely to provide more effective protection in future Precise rapid detection kits may aid in understanding the specific pathogen and developing management methods. In this chapter, all these diseases and the causative agents were discussed in detail. The host range, biology, etiology and management aspects are presented in the chapter.