3.6.9
IMPACT OF VARIETY, PLANTING DATE AND PLANT PROTECTION ON BLAST DISEASE AND GRAIN YIELD OF RICE IN RAINFED CONDITIONS

RBS SANGAR

IGAU, Zonal Agricultural Research Station, P.B.No. 03, Ambikapur-497001, Madhya Pradesh, INDIA

Background and objectives
Blast disease caused by Pyricularia grisea (Cooke) Sacc. is a limiting factor for rice cultivation [1]. It is caused grain yield losses 80% or more [2]. It is also important in our region. Therefore study was made to see the integrated impact of variety, planting date and plant protection on the management of blast disease and grain yield of rice.

Materials and methods
Trial was done in split plot design with 3 replications at research farm of Ambikapur during Kharif 1994 to 1996. Treatments were variety Rasi, Kranti and IR 50; planting on July 15, 30 and August 14, 29 and spray of hinosan @ 0.1% at tillering and dough stages. Observations on disease incidence and yield were taken randomly by 0.5 m2 quadrate in each treatment. Number of damaged/healthy hills, tillers, panicles were noted separately out of total hills observed.

Results and conclusions
The significant increase in grain yield and minimum blast incidence in all three varieties were recorded when they planted early as compared with late planted crop. AmonR varieties the higher yield and minimum disease incidence were noted in resistant variety Rasl followed by Kranti and maximum in susceptible variety IR 50. The adoption of plant protection gave significant more yield in varieties tested in early planted crop than late. It was also observed that adoption of plant protection increase the yield of resistant variety compared with no plant protection in early crop. An early planting of resistant variety with plant protection found to be important to manage the incidence of blast disease and increase grain yield of rice.

References
1. Bhatta JC, Singh RA, 1992. I. Diseases of Cereals & Pulses Eds. Singh et al; pp.80-115. Prentice Hall, New Jersey.
2. Pinnschmidt H, Kranz J, 1989. Plant Res. Dev. 29 : 86-95.