Validação cruzada com correção de autovalores e regressão isotônica nos modelos de efeitos principais aditivos e interação multiplicativa

This paper presents an application of AMMI models - Additive Main effects and Multiplicative Interaction model - for a thorough study about the effect of the interaction between genotype and environment in multi-environments experiments with balanced data. Two methods of crossed validation are presented and the improvement of these methods through the correction of eigenvalues, being these rearranged by the isotonic regression. A comparative study between these methods is made, with real data. The results show that the EASTMENT & KRZANOWSKI (1982) method selects a more parsimonious model and when this method is improved with the correction of the eigenvalues, the number of components are not modified. GABRIEL (2002) method selects a huge number of terms to hold back in the model, and when this method is improved by the correction of eigenvalue, the number of terms diminishes. Therefore, the improvement of these methods through the correction of eigenvalues brings a great benefit from the practical point of view for the analyst of data proceeding from multi-ambient, since the selection of numbers of multiplicative terms represents a profit of the number of blocks (or repetitions), when the model AMMI is used, instead of the complete model.

Adaptabilidade e estabilidade de clones de cana-de-açúcar no Estado de São Paulo

Pós-graduação em Agronomia - FEIS

Adaptabilidade e estabilidade de cultivares de milho para diferentes safras, espaçamentos e populações de plantas

Pós-graduação em Agronomia - FEIS

Adaptabilidade e estabilidade de clones de cana-de-açúcar

The objective of this study was to identify clones of sugarcane with good stability and adaptability in the State of São Paulo, Brazil, and also identifying locations most representative for selection and experimentation. Ten clones and two commercial checks of medium-late maturation were evaluated in the first-ratoon of experiments harvested in August 2009, using bissegmented regression and AMMI (Additive Main Effects and Multiplicative Interaction Analysis) methods. The results of two methods were compared and they evidenced that the clones RB975201, RB975157, RB975932, RB975242 and RB975162 are the most promising, showing higher production when compared to the checks, higher stability observed in one or both statistical methods and broader or more specific adaptability. The environment Tarumã presented higher stability and capacity to discriminate genotypes, allowing an ordering more reliable as compared to the overall mean of the environments tested.

Produtividade, estabilidade e adaptabilidade em progênies de eucalyptus urophylla s.t. blake

Pós-graduação em Agronomia - FEIS

Abordagem genética e multivariada na performance agronômica de genótipos de soja oriundos de diferentes genealogias

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV