Annals of Plant Protection Sciences
Year : 2002, Volume : 10, Issue : 2
First page : ( 277) Last page : ( 281)
Print ISSN : 0971-3573.

Assessment of Yield Loss in Rice Due to Bacterial Leaf Blight Using Simulation Models

Chander Subhash, Aggarwal P.K., Reddy P.R.*

Centre for Applications of Systems Simulation, NRL Building, I.A.R.I., New Delhi II0 012.

* Central Rice Research Institute, Cuttack 753 006, India.

Abstract

The yield loss simulation (YLS) model was used to simulate the effect of bacterial leaf blight (BLB) on growth and yield of rice cultivar, IR-64. Simulation results of the YLS were then, compared to that of the blight model. The YLS was a multi-pest model in which damage mechanisms were simulated for foliar diseases-BLB/sheath blight, stem borer and weeds. The damage mechanisms of the BLB considered in the model were the reduction in leaf area index(LAI) and leaf weight. The blight model was based on the Oryza-1 model, and simulates the effect of BLB/sheath blight on the rice growth and yield. The major damage mechanisms of BLB considered in the model affect the characteristics of the photosynthesis light response curve. The stem and the storage organ weights were simulated better by the YLS than the blight. The simulated reduction in the total dry matter (TDM) due to BLB with the YLS and the blight varied from 17.6–22.1 and 6.6–15.5%, respectively as compared to the observed reduction of 11.9–21.4% in different disease treatments. The effect of disease was, thus overestimated by the YLS while it was underestimated slight by the blight. Both the models need further improvement in quantification of damage mechanisms of BLB.

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Key words

Bacterial leaf blight, Rice, Simulation model, Yield loss.

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