Viscosity of triticale varieties differs in its response to temperature after flowering

Triticale produced to feed monogastric livestock needs to have a low potential applied viscosity (PAV). Five varieties were cultivated at nine locations (430-700 m a.s.l.) in Switzerland over three years. Six of the locations were sampled for at least two consecutive years, and PAV was related to meteorological data. The data was subjected to correlation and regression analysis, as well as a multiplicative model, to evaluate interactions. Extent and stability of PAV differed between experimental locations across all genotypes, notably between varieties and years, but also between single locations in the same year. Interactions between genotype and environment were responsible for up to 12% of the PAV variance. With the exception of one variety, PAV was negatively correlated with the cumulated mean temperatures over a 20-day period, starting on day 24 after heading. In these cases, temperature data explained the differences in PAV much better than precipitation did. By linear regression, PAV could be predicted from mean temperature during grain development and grain hardness at harvest for the four thermosensitive varieties. Two varieties were of particular interest, as they had either a favorably low PAV (Tridel) or a PAV resistant to environmental influences (Prader). A combination of these two traits could be used to create a type of triticale particularly suitable for livestock feeding.