Standardization of artificial inoculation methods for neck blast disease development in rice
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Authors
Rajyalakshmi Bobbala
Dept. of Plant Pathology, SV Agricultural College, Tirupati, ANGRAU
Keywords:
Rice, Neck blast, Magnaporthe oryzae, Inoculation methodsAbstract
Neck blast caused by Magnaporthe oryzae is a destructive phase of rice blast disease, leading to severe yield losses under favourable conditions. Reliable artificial inoculation is essential for screening rice genotypes against neck blast under controlled conditions. The present study was conducted to standardize an effective inoculation method for inducing neck blast disease in rice. Four inoculation methods, viz., injection, smearing, spraying and tying of inoculum bits, were evaluated along with an uninoculated control. Disease severity was recorded as Per cent Disease Index (PDI) at 5, 10 and 15 days after inoculation (DAI), and disease progress was estimated using Area Under Disease Progress Curve (AUDPC). Among the methods tested, injection recorded the highest PDI of 16.67, 36.67 and 68.89 per cent at 5, 10 and 15 DAI, respectively, with the highest AUDPC value of 439. Tying of inoculum bits was next effective, recording 53.33 per cent PDI at 15 DAI and an AUDPC of 347. Smearing showed moderate infection, while spraying recorded the lowest disease development. Thus, injection was identified as the most reliable method for artificial neck blast induction.
References
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