Studies on Incidence and Severity of Different Diseases in Drought Tolerant Rice Varieties Under Different Establishment Methods

Abstract

In present investigation three drought tolerant varieties of rice namely, shahbhagi dhan, IR-64, and Ir-64 drt-1 were evaluated for their susceptibility against bacterial leaf blight, rice blast, brown spot and false smut of rice. All the three varieties were grown using four different crop establishment method viz. puddle transplanting, unpuddled transplanting, direct seeding with wheat-straw mulch and direct seeding without mulch. All the three varieties under four establishment methods were also provided with two moisture conservation techniques i.e. application of pusa hydrogel and no application of pusa hydrogel. All the three varieties i.e. shahbhagi dhan, IR-64 and IR-64 drt-1 were almost equally susceptible to bacterial leaf blight. Among the four crop establishment methods direct seeding without mulch resulted in higher incidence and severity of bacterial leaf blight. Shahbhagi dhan found to be more susceptible to rice blast whereas, rest two varieties IR-64 and IR-64 drt-1 were comparatively less susceptible to rice blast. Severity of rice blast was more in direct seeded rice whereas, there was less severity of rice blast in unpuddled transplanted rice. Shahbhagi dhan showed highest severity of brown spot disease. IR-64 and IR-64 drt-1 showed less severity of brown spot disease. In direct seeded rice, severity of brown spot was comparatively higher than in case of transplanted rice. Pusa hydrogel had not any significant effect on increase or decrease of any of the three diseases. All three varieties resulted in almost similar number of total tillers and effective tillers. Direct seeded method of rice resulted in highest number of total and effective tillers in comparison to transplanted method of rice which resulted in comparatively less number of total and effective tillers.Ir-64 and IR-64 drt-1 resulted in almost similar weight of thousand grains and they were highest whereas, shahbhagi dhan had lowest weight of 1000 grains.Ir-64 drt-1 resulted in highest weight of ten ear and highest yield also which were recorded in the rice established through puddled transplanting method.