00000ctm a22000004i 4500 UP-99796217613162727 Buklod 20191025091712.0 m |o d | ta 191025s2015 xx d r |||| u| (iLib)UPD-00414267375 DARCHIVES rda eng DMLUC LG 995 2015 A64 B53 Blas, Nikki T. author. A mathematical model of transmission of rice tungro diseases by nephotettix virescens Nikki T. Blas ; Fredegusto Guido P. David, adviser. Quezon City Institute of Mathematics, College of Science, University of the Philippines Diliman 2015. xii, 81 leaves illustrations 28 cm. text rdacontent unmediated rdamedia volume rdacarrier Thesis (M.S. Applied Mathematics)--University of the Philippines Diliman December 2015. Not available to the public. One of the major threats in rice agriculture is the tungro virus, which is transmitted semi-persistently to rice plants via green rice leafhoppers called nephottetix virescens. Tungro is polycyclic and complex disease of rice associated by dual infection with Rice Tungro Bacilliform Virus (RTBV) and Rice Tungro Spherical Virus (RTSV). Interaction of the two viruses results in the degeneration of the host. In this paper, we used a plant-vector system of ordinary differential equations to model the spread of the disease in a model rice field. Parameter values were obtained from studies on the entomology of Nephottetix Virescens and infection rates of RTSV and RTBV. The system was analyzed for equilibrium solutions, and solved numerically for resistant and susceptible rice varieties. Rice tungro spherical virus. Mathematical models. David, Fredegusto Guido P. adviser. FI UPD DARCHIVES LG 995 2015 A64 B53 Thesis