Emerging Minor Diseases of Rice in India: Losses and Management Strategies

Abstract

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.

Inhibitory role of copper and silver nanocomposite on important bacterial and fungal pathogens in rice (Oryza sativa)

“…Rice is the most important staple food for more than two billion population in the South-East Asian countries and Africa. Various diseases of the rice crop are major causes of yield losses that ultimately adversely affect the annual rice production and productivity 1 , 2 . Among the different fungal and bacterial diseases of rice, sheath blight and bacterial leaf blight (BLB) are the major diseases that interfere with grain maturity and quality causing yield loss in the range of 10–50% in India as well as at the global level 3 .…”

Poprawa Zdrowia Upraw Dzięki Cyfrowemu Bliźniakowi Do Monitorowania Chorób I Równowagi Składników Odżywczych

“…In the previous year (2022 /23), global rice production reached 513.68 million tons, and projections for this year estimate a potential rise to 518.14 million tons, reflecting the constant effort to meet increasing demand [18]. India, cultivating rice across 43 million hectares, faces the challenge of maintaining an average productivity of 2.6 tons per hectare [19].…”

“…Rice cultivation, despite its significance as a global staple, faces formidable challenges due to diseases, presenting biotic hurdles that can result in yield reductions ranging from 20% to 100% [19]. Chief among these challenges is rice blast, triggered by the fungus Magnaporthe oryzae (formerly Magnaporthe grisea) standing out as the most impactful disease that inflicts annual yield losses ranging from approximately 10% to 30%.…”

Genetic diversity and pathogenicity of fungi associated with rice sheath rot in the Fogera plain, Northwest Ethiopia

“…Major diseases include sheath rot, blast disease, sheath blight, tungro viruses, brown spots and several grain discoloration diseases (Ayyadurai et al., 2005; Gnanamanickam, 2009; Kabore et al., 2022; Park et al., 2008; Pramunadipta et al., 2022). Rice sheath rot has emerged as a major disease around the world (Shivappa et al., 2022) and poses a significant threat to rice production, resulting in a reduction of rice yields by as much as 85% (Bigirimana et al., 2015). It affects rice crops in almost all growing ecosystems, primarily attacking the uppermost leaf sheaths that enclose young panicles during the boot stage.…”