Results of the 21st and 22nd international triticale screening nurseries (ITSNs) 1989-90 and 1990-91

anglais. The 21st and 22nd ITSNs were sent to cooperators in 1989 and 1990, respectively. CIMMYT sent 125 nurseries to 108 cooperators in 65 countries in the 21st ITSN and 119 nurseries to 96 cooperators in 58 countries in the 22nd ITSN. The 290 advanced lines and checks (150 in the 21st and 140 in 22nd) had been chosen from among CIMMYT's best materials. All had been grown and observed in a high-yielding environment with pressure from major diseases in the Yaqui Valley of Northwestern Mexico. The seed source for these international nurseries was the Hermosillo Experiment Station, Sonora, Mexico. The seed was cleaned and treated with a mixture of Terrazan and Vitavax before shipment. Enough seed from each line was provided for an unreplicated double row, at least 2 m long. 53 (21st ITSN) and 61 (22nd ITSN) of the cooperators receiving the nursery returned field books. The choice of variables measured and the data returned rest with the individual cooperators. We have summarized selected variables that were reported. 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 tables; this may be an important indication of the level of credibility that should be inferred. Also bear in mind that the yield reported is from a single, unbordered plot grown for observation rather than as a rigorous, replicated yield trial

espagnol; castillan. En 1989 y 1990 el CIMMYT distribuyo 125 viveros del 21 ITSN a 108 colaboradores de 65 paises y 119 viveros del 22 ITSN a 96 colaboradores de 58 paises. Las 290 lineas avanzadas y testigos (150 en el 21 ITSN y 140 en el 22 ITSN) se eligieron entre los mejores materiales del CIMMYT. Todos se cultivaron y observaron en un ambiente de alto rendimiento bajo presion de las principales enfermedades en el Valle del Yaqui, en el noroeste de Mexico. La semilla empleada en estos viveros procede de la Estacion Experimental de Hermosillo, Sonora, Mexico, y, antes de enviarla, fue limpiada y tratada con una mezcla de Terrazan y Vitavax. Se sumistro suficiente semilla para sembrar un surco doble sin repeticiones de por lo menos 2 metros de longitud. 53 de los colaboradores del 21 ITSN y 61 del 22 ITSN que recibieron los viveros enviaron los libros de campo con los datos correspondientes a sus localidades. Los colaboradores eligen las variables que desean evaluar y los datos que envian. El numero de observaciones difiere de una variable a otra. Se recomienda a los lectores tener en cuenta el numero de observaciones que aparecen en la parte superior de la columna correspondiente a cada variable, ya que puede ser un importante indicador del grado de credibilidad que debe inferirse