Leaf share, plant age and growth season are often overlooked as modifiers of the biomass quality in energy crops. The current work studied the effect of the given factors on the biomass yield and the biomass quality in Elephant grass CT115, intended for bioethanol production, in Veracruz, Mexico. Two seasons per year, 5 months each, were tracked on a 2-weeks basis. The climate is warm wet with summer rains, 1,142 mm of annual rainfall, and 26 °C monthly temperature. From day 56 of the wet season or from day 84 of the dry season, stems accumulated 12 or 6 Mg ha⁻¹, respectively, while green leaves increased only 1 Mg. Higher biomass quality was recorded for the leaf fraction, or for the wet season regrowth. For instance, lignin contained in stems meant twice that of leaves, whereas stems recorded 20% less lignin in the wet season as compared to the dry season. Despite holocellulose being similar between fractions or seasons, hemicellulose and cellulose showed inverse correlation, while lignin and cellulose contents were directly correlated in stems. Increasing the annual harvest of green leaves will improve biomass quality, which is known to increase biodegradability and might improve the annual ethanol yield.

The daily path of the Sun across longitude yields night and day, but the Sun also travels across latitude on a belt 47° wide. The solar meridian declination explains the latitudinal budget of natural beam irradiance (NBI), which is defined as the irradiance delivered to the Earth’s surface as a normal projection from the Sun. Data for the Sun meridian declination were obtained from the Spencer model, known as the geometric model. The distribution of NBI was weighed for the latitudinal belt between the Tropics of Cancer and Capricorn. The variation in the parameters of solar meridian declination were found to be analogous to that of pendular motion. The joint distributions of the solar meridian declination against its own velocity, or that of the velocity against the acceleration of solar meridian declination, displayed circular functions. The NBI budget that a particular latitude gathers, fluctuates in inverse proportion to the velocity of solar meridian declination, yielding 18 sun-paths per degree for latitudes above 20°, or 6 sun-paths per degree of latitude for latitudes under 20°. At an average Sun–Earth distance of 1 AU, all sites of the planet, whose latitude coincides, whether within or between hemispheres, accumulate an equivalent budget of NBI.

The aim of the study was to assess tiller population dynamics of aerial and basal tillers in eight cultivars of Pennisetum purpureum (Schumach.), syn. Cenchrus purpureus (Schumach.) Morrone, in a warm humid climate in Veracruz, Mexico. This is a pioneer study on tiller population dynamics in elephant grass under conditions of undisturbed growth. The tiller population assays included data from 14 days after cutting until 154 and 182 days after cutting for the dry and wet seasons, respectively. On each sampling date, a distinctive ring was placed on every new tiller, and rings were removed from dead tillers. Tiller density, mortality and appearance were determined. In wet seasons, copious tillering occurred on initial regrowth (by day 42, mostly aerial tillers, with a ratio of 2:1 to 4:1 for aerial to basal tiller appearance), and on day 98 (a higher proportion of basal tillers, with an aerial to basal tiller ratio of 1.5:1). Aerial tillers showed a higher overall mortality rate than basal tillers (29.0 vs ...

The runs of homozygosity (ROHs), the inbreeding coefficient, and the effective population size (Ne) in Pelibuey sheep were analyzed in 24 Pelibuey ewes from two lambs at parturition and 24 ewes that gave birth to a single lamb using the Ilumina OvineSNP50 BeadChip. The Ne decreased from 535 to 192 in the first ten generations. A total of 2194 ROHs were identified on the basis of single nucleotide polymorphisms (SNPs), were identified in the prolific group and 2185 SNPs in ROH in the non-prolific group. The distribution of the lengths of the ROH, considering both groups, were found to be: 4065 less than 6 Mb, 213 between 6 and 12 Mb, 72 between 12 and 24 Mb, twenty between 24 and 48 Mb and 8 greater than 48 Mb. In prolific sheep, the ROH associated with prolificacy were identified near the LINGO2, FLRT2, ADGRB3 genes, related to “positive regulation of synapse assembly”; and the DGKG, DGKE, DGKB and DGKI genes, related to “protein kinase C-activating G-protein coupled receptor signaling pathway”. The present work present genes that can function as signal mediators or have activity in embryonic development, which is relevant to the economic activity of this species.