Determinación de los patotipos del nemátodo dorado globodera rostochiensis (woll.) behrens 1975, en una población de navidad, n. l. y sus efectos en los rendimientos de tres variedades de papa.

"Uno de los problemas fitosanitarios que enfrenta el cultivo de la papa en Navidad, N.L. es el nemátodo dorado de' la papa que puede generar dos tipos de pérdidas en el cultivo, las directas que se refieren a las mermas en la producción, y las indirectas que incluyen gastos de control y medidas cuarentenarias que se aplican para evitar la dispersión del nemátodo y se convierten a menudo en una restricción tanto de papa para consumo como para semilla, siendo este último caso donde no se pueden aumentar las ganancias debido a que se impide la comercialización hacia zonas libres."

"Objectives of this research were to locate a population of Globodera rostochiensis in arder to extract inoculum from it, to determin pathotypes present in itas well as to evaluate effects of different densities of inoculum of the nematode on yields and sorne other associated variables in three varieties of patato; Norteña, Alpha and Atlantic. A population of cyst nematode of 403 cysts per liter of ground was located in the ejido Navidad, in the municipality of Galeana, in the mexican state of Nuevo Leon from where inoculum was extracted; in it the sole presence of pathoptype RIA was detected. Such a pathotype did not af fect yields of variety Atlantic since it preved to be resistent to it, however varieties Alpha and Norteña showed a negative correlation between densities of inoculum and yields, as well as with sorne other associated variables. Variety Alpha registered a maximum loss of 51.52 per cent in infestations of 178.06 ovi per gram of ground, and of 80.27 per cent in inoculum density of 244.84 ovi per gram. Both varieties showed a maximum increment of inoculum of 2897.19 per cent in Alpha and of 4297.97 per cent in Norteña when inoculated with the minimum densitiy of 22. 26 ovi per gram of ground utilized in the experiment."