Results of the eighteenth international barley observation nursery (IBON)

anglais. The eighteenth international barley observation nursery (IBON) was sent in September 1990 to be grown by cooperators in their spring season of 1991. Ninety-two nurseries went to cooperators in 49 countries. The 136 advanced lines and checks in the nursery had been chosen from among the best materials. All had been grown and observed by scientists in a high yield environment under pressure from major diseases at the CIANO Experiment Station in northwest Mexico. There, seed for this international nursery was multiplied, cleaned, and treated with fungicides before shipment. Thirty-eight of the cooperators receiving the nursery returned field books with performance data from their locations in time to be included in this report. The choice of variables measured and the data returned rest with the individual cooperator. We have included in this summary selected variables reported to us. The number of observations differs from variable to variable. The reader is urged to note the number of observations at the head of each variable column in the summary table; this may be an important indicator of the level of credibility at should be inferred. The reader should also bear in mind that the yield reported is from a single plot essentially grown for observation rather than as a rigorous, replicated yield trial

espagnol; castillan. El 18avo. vivero internacional de observacion de cebada (IBON) fue distribuido en Septiembre de 1990 para que los cooperadores lo sembraran en el ciclo de primavera de 1991. Se enviaron 92 viveros a cooperadores de 49 paises. Las 136 lineas avanzadas y testigos incluidos en los viveros fueron seleccionados entre nuestros mejores materiales. Todos fueron cultivados y observados por nuestros cientificos bajo presion de las principales enfermedades en un ambiente con alto potencial de rendimiento, en la estacion experimental del CIANO en el noroeste de Mexico, donde se multiplico la semilla; antes de su distribucion se lavo y trato con fungicida. 38 de los cooperadores que recibieron el vivero devolvieron los libros de campo con los datos de comportamiento de sus localidades. Cada cooperador elige las variables que observara y los datos que devolvera. Hemos incluido en este resumen las variables reportadas. El numero de variables en diferente para cada variable. Instamos al lector a que tome nota del numero de observaciones que se presentan en el encabezado de cada columna de variables, ya que puede ser un indicador importante del nivel de credibilidad que debe inferirse