The present work “Determination of the infectious capacity of Tagosodes orizicolus (Muir), vector of the VHBA by means of the test of the susceptible plant (Echinochloa sp) in the valley of the first floor May”.; I use the objective of determining the infectious capacity of the population of Tagosodes orizicolus, Vector of the VHBA using like susceptible plant to Echinochloa sp. in the Valley of the First floor May, San Martin; the present investigation work one carries out in the hothouse of the Ability of Agrarian Sciences of the National University of San Martin. You uses the design Totally at random (DCA), with 23 treatments and 03 Observations. The treatments were the committees of regantes of the whole valley of the first floor May T1 (Moral), T2 (Union Cocopa), T3 (Rosanaico), T4 (First of October), T5 (Cumbacillo) T6 (Cachaboya), T7 (I Triumph), T8 (Future), T9 (Saint John th...