Evaluación de cultivares de raigrás italiano e híbrido como cultivo de invierno para ensilar en primavera

TLDR: In this article, the authors compare the performance of different ryegrass cultivars in terms of drymatter and digestible organic matter (DOM) yield in two different cutting dates.

Abstract: alian ryegrass(Lolium multiflorum) cultivars, two alternative (“Promenade” and “Major”) and two non-alternative (“Sultan” and “Danergo”), and two hybrid ryegrass(Loliumboucheanum) cultivars(“Barladin” and “Barsilo”) were sown as monoculturesin the autumn of 2011 at the CIAM (coastal zone of Galicia, NW of Spain) in an experiment following an split-plot design with cultivar asthemain-plot, cutting date (sixfirst-cut datesfrom6March to 17May, followed by a second cut of regrowths at six weeks of age) as the sub-plot and ten replicates. No significant effect of cultivar in terms of drymatter (DM) and digestible organicmatter (DOM)yieldswas detected in any of the two cuts,showing all the cultivars high herbage yields(7.4 and 5.4 t DMha-1 and 5.2 and 3.5 t DOMha-1, first and second cut,respectively).Average values of crude protein (CP) content were low and, inversely,watersoluble carbohydrates(WSC) content was high in all cultivars(CP: 9.1 and 8.9 %; WSC: 28.0 and 22.6 %, first and second cut, respectively),showing onlyminor differences amongst cultivars within each cut. In the first cycle herbage yield increased from3.2 t DMha-1 and 2.3 t DOM ha-1 in earlyMarch to amaximumof 9.9 t DMha-1 and 6.7 t DOMha -1 in the first week ofMay when all ryegrassspecies headed. Average CP content was 14.7 % in the first cutting date, dropping to 6.5 % at the beginning of the heading stage. It is concluded that winter ryegrassis a high-yielding, energy-rich crop forsilage, although protein content can be verylow in late cuts. Alternative cultivars are preferable for early harvestsin spring, whilst non-alternative and hybrid ryegrasses are the best option for cuts around the heading stage.