A new method to assess competition in coffee clonal trials with single-tree plots in Cote d'Ivoire
A new method is proposed for the assessment of competition in clonal trials with completely randomized single-tree plots, without needing to choose a covariable a priori linked to competition. This method was applied to a robusta coffee (Coffea canephora) clonal trial planted in a completely randomized single-tree plot design located in Cote d'Ivoire. Microenvironmental effects were first taken into account using the conventional Papadakis method. The competition effect of each clone was then estimated as the influence of its presence on the residual value, after removal of the clonal effect, of its neighbours. Residuals were thus modelled as a linear regression of the neighbouring clones' C value. Competition effects were shown this way to explain 4 percent of the residual yield in young trees and 10 percent in adult trees. Several clones had C values significantly different from 0. Some were identified as aggressive for their neighbours (C minor who 0), others as stimulating (i.e., promoting yield, C major who 0). Architectureand vigour variables that were likely to be related to the C value of clones were then sought. For young trees, vigour estimated by stem diameter, was best correlated to competition effects: vigorous clones were more aggressive than others. When the trees became adult, the length of the orthotropic internodes (Lort) was the trait that most effectively explained the competition effect (42
| Main Authors: | , , |
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| Format: | biblioteca |
| Published: |
2001
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| Subjects: | COFFEA, COFFEA CANEPHORA, VARIACION CLONAL, CLONES, APTITUD COMBINATORIA, INTERNODIOS, METODOS, COMPETICION VEGETAL, EFECTOS RESIDUALES, INDICE DE SELECCION, TALLOS, VIGOR, |
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