Chapters authored
Management of False Smut Disease of Rice: A Review
Rice (Oryza sativa L.) is the most important food crop of the developing world. Among the biotic stresses of false smut is an emerging disease caused by Ustilaginoidea virens. The disease reduces both the quality and quantity of rice. The pathogen produces mycotoxins that are harmful to animals and humans. The disease is severe when favorable environmental conditions like high humidity (more than 80%) and temperature ranging from 25 to 30°C, late sowing and high soil fertility as well as using high amount of nitrogen. It has gained the status of a major disease of rice and causing varying yield loss depending on the weather conditions during the crop-growing period and the genotypes. Therefore, the primary concern of the farmers is the disease management methods, which are effective, simple and practical. Since, there is no single effective management strategy for false smut, we have discussed about the potential management options available depending upon the economic status and adoption capacity of the farmers. In the Plant Pathologists point of view, eco-friendly methods of disease management like cultural, biological and use of resistant variety should be advocated for sustainability of agriculture and human being.
Part of the book: Cereal Grains
Emerging Minor Diseases of Rice in India: Losses and Management Strategies
Rice (Oryza sativa L) being one of the imperative food crops of the word contributes immensely to the food and nutritional security of India. The cultivation of rice is changed over the decades from a simple cultivation practices to the advanced cultivation to increase yield. Increased in rice yields especially after 1960s is mainly due to the introduction of high yielding semi-dwarf varieties which requires more inputs like chemical fertilizers, water and other resources. As a result, India achieved self sufficiency in rice and currently producing more than 115 MT of rice to meet country’s demand. Now India is exporting rice to other nations and earning foreign returns. With the change in rice cultivation practices, problems also aroused side by side. A number of biotic and abiotic stresses emerged as major constraints for rice cultivation in diverse agro-climatic conditions and growing ecologies. Diseases are the major biotic constraints to rice which can reduce the yields by 20–100% based on severity. Major diseases like blast, brown spot, bacterial blight, sheath blight and tungro still causing more damage and new minor diseases like bakanae, false smut, grain discoloration, early seedling blight, narrow brown spot, sheath rot have emerged as major problems. The losses due to these diseases may 1–100% based on the growing conditions, varietal susceptibility etc.., At present no significant source of resistance available for any of the above emerging diseases. But looking into the severity of these diseases, it is very important to address them by following integrated management practices like cultural, mechanical, biological and finally chemical control. But more emphasis has to be given to screen gerrmplasm against these diseases and identify stable source of resistance. Finally utilizing these sources in resistance breeding program by employing molecular breeding tools like marker assisted selection (MAS), marker assisted back cross breeding (MABB), gene pyramiding and transgenic tools. The present chapter discusses the importance of these emerging minor diseases of rice, the losses and possible management measures including resistance breeding.
Part of the book: Integrative Advances in Rice Research