Multivariate analysis of the agronomic performance and forage quality of new clones of Pennisetum purpureum drought tolerant in Valle del Cauto, Cuba

Resumen

With the new clones of Pennisetum purpureum drought tolerant, obtained from the progenitor Cuba CT-115, agronomic and biomass quality studies were carried out in an ecosystem of intense seasonal drought in Valle del Cauto. With these results, a multivariate analysis was performed to determine the weight variables in the agronomic performance and its relative contribution to the classification of the promising clones for drought conditions. In the analysis for the rainy season, two components that explained 71.04 % of the total variance were extracted. The weight variables were height, length and wide of leaf, stem thickness, yield of total DM and leaves , absolute growth rate and leaf area. For the dry season, two components that explained 76.63 % of the total variance were extracted, the weight variables coincided, except the stem thickness, and the number of green leaves / plant and the number of branches was also significant. In the grouping dendograms, three groups at each time of the year were formed. In rainy season,
one group showed a promising performance (CT-600, CT-601, CT-603, CT-605, CT-608 and CT-609). With the exception of leaf wide, this group achieved the highest expression of the weight variables; another group achieved an intermediate performance including Control Cuba CT-115, CT-602 and CT-607. The group formed by CT-604 and CT-606 had lower height, lower absolute growth rate and lower yields of dry matter. In the dry season, a poor performance group appeared, with CT-604, CT-606 and CT-602. The remaining groups showed some similarity. It is concluded that the performance of these clones is very marked by the season of the year. The CT-606, CT-604 and CT-602 are highlighted for their low biomass production.
Key words: establishment, cut, yield, season of the year