We investigated a new method for the establishment of dwarf Napiergrass by covering stem cuttings with soil in the winter season analogously to summer establishment in sugarcane. Three experiments were conducted, including measuring the labor involved in plant establishment, and an extension study was applied to livestock producers’ fields in two locations. Using this technique, we obtained an emerged plant density of over two plants/m². Moreover, this proved a simple and labor-saving method compared with manual or mechanical transplanting. Sowing of Italian ryegrass at the same time as covering cuttings of dwarf Napiergrass with soil could control spring weed growth without disturbing the emergence of dwarf Napiergrass, suggesting the feasibility of a double-cropping forage production system in the region.

Fermentation quality of dwarf napiergrass (Pennisetum purpureum Schumach) was estimated for additives lactic acid bacteria and Acremonium cellulase (LAB + AC), fermented juice of epiphytic lactic acid bacteria (FJLB), and a no-additive control in 2006 via two ensiling methods—round-bale and vinyl-bag methods in 2006—and via two ensiling seasons—summer and autumn of 2013. Fermentation quality of dwarf napiergrass ensiled in the summer season was improved by the input of additives, with the highest quality in LAB + AC, followed by FJLB; the lactic acid content was higher, and the pH and sum of the butyric, caproic, and valeric acid contents were lower, resulting in an increase in the V-score value by each additive. The ensiling method in autumn without additives affected fermentation quality, mainly due to the airtightness, which was higher for round-bale processing than in vinyl bags, even with the satisfactory V-score of 72. Fermentation in round bales without additives had a higher quality in autumn than in summer, possibly due to the higher concentration of mono- and oligo-saccharides. Thus, it was concluded that dwarf napiergrass can be produced to satisfactory-quality silage by adding LAB + AC or FJLB in summer and even in the absence of additives in autumn.

Round-bale silage harvesting and processing methods were assessed to evaluate overwintering ability and dry matter (DM) yield, fermentation quality and palatability of overwintered dwarf Napiergrass (Pennisetum purpureum Schumach) in the two years following establishment in Nagasaki, Japan, in May 2013 using rooted tillers with a density of 2 plants/m². In 2014, harvesting methods under no-wilting treatment were compared for flail-type harvesting with a round-baler (Flail/baler plot) and mower conditioning with a round-baler (Mower/baler plot), which is common for beef-calf–producing farmers in the region. In 2015, the effect of ensilage with wilting was investigated only in the Mower/baler plot. Dwarf Napiergrass was cut twice, in early August (summer) and late November (late autumn), each year. The winter survival rate was greater than 96% in May both years. The DM yield in the Mower/baler plot did not differ significantly for the first summer cutting or the annual total from the Flail/baler plot, but did show inferior yield for the second cutting. The fermentation quality of the second-cut plants, estimated using the V2-score, was higher in the Flail/baler plot than in the Mower/baler plot, possibly because of higher air-tightness, and the second-cut silage tended to have better fermentation quality than the first-cut silage in both harvesting plots. Wilting improved the fermentation quality of dwarf Napiergrass silage in summer, but not in autumn. The palatability of the silage, as estimated by alternative and voluntary intake trials using Japanese Black beef cattle, did not differ significantly between plots. The results suggest that dwarf Napiergrass can be better harvested using a mower conditioner with processing by a round-baler, an approach common to beef-calf–producing farmers, than with the flail/baler system, without reducing the persistence, yield, or palatability of the silage. Moreover, wilting treatment improved the fermentation quality of the dwarf Napiergrass silage when processed in summer.

A linear regression model for predicting total digestible nutrient (TDN) concentration in forage rice (Oryza sativa L.) silage was previously developed with traditional cultivars (>30% dry matter, DM as panicle), and we here extend the linear regression model to two short-panicle cultivars, ‘Tachisuzuka’ and ‘Tachiayaka’ (<20% DM as panicle). Silage fermentation quality was superior for the short-panicle cultivars compared to the traditional ones, partly due to higher mono- and oligosaccharide concentrations in leaves and stems. Silage TDN concentration was previously estimated for traditional cultivars by in vitro dry matter digestibility (IVDMD) and crude ash (CA) concentration (estimated TDN = 0.329 × IVDMD − 0.688 × CA + 44.5, r² = 0.815, p < 0.001). In vivo TDN concentration in silages of short-panicle cultivars, ranging from 49.5 to 58.3%, was nearly identical to the TDN concentration estimated by the equation with an error rate <5%, demonstrating that the new equation model can be satisfactorily applied to silages of short-panicle rice cultivars.

"Temperature response comparison of controlled and field environments for four tropical grasses" published on 01 Nov 2005 by Wageningen Academic.