Growth analysis of five spring and five winter triticale genotypes

Little is known about the pattern of growth and biomass partitioning of spr ing and winter triticale (XTrificosecale Wittmack), although such informati on can aid in interpreting the results of field experiments and is an essen tial step in the development of crop simulation models. This study was cond ucted to analyze and compare the growth of five winter and five spring trit icale genotypes over two years in northeast Spain. Plants were sampled at t he main stages of the Zadoks scale, and biomass, LAI and their components, and stem elongation were determined. The relationships between an the growt h traits studied and accumulated growing degree-days from sowing (GDD) were described by the same asymmetric logistic peak curve. Genotypic variabilit y could be mainly associated with plant phenology. On average, winter triti c ale types needed 165 more GDD than spring types to reach maximum LAI. Als o, winter triticale genotypes needed 190 more GDD to complete their main st em elongation, and 109 more GDD to reach their maximum rate of dry weight a ccumulation in the stems than spring genotypes did. The length of the first tiller was closer to the length of the main stem in winter types than in s pring types. Both types of triticale had similar patterns of biomass accumu lation. The asymmetric logistic peak curve used in this work fitted asympto tic and peak-type relationships, and can be a useful tool for growth studie s.