Se estudió la morfología y producción forrajera en 16 ecotipos de Cenchrus purpureus (Schumach.) Morrone, en condiciones subtropicales del estado de Nayarit, México. El estudio se realizó en el Sitio Experimental El Verdineño-INIFAP. Los materiales evaluados incluyeron: Elefante, Uruguana, Taiwán, CT-169, Caña Africana, Maralfalfa, Mott, Roxo, King Grass morado, CT-115, Merkerón, Camerún, King Grass verde y tres ecotipos de Tamaulipas: Elefante Tamps, Maralfalfa Tamps y Roxo Tamps, establecidas en parcelas de 2 x 4 m2, con tres surcos de seis plantas cada uno, a razón de 25 000 plantas ha-1. Las evaluaciones se realizaron durante la época de déficit hídrico enero-julio de 2019 a 180 días de rebrote. Las variables morfológicas incluyeron: altura de planta, densidad de tallos por corona, diámetro basal y central de tallo, ancho y longitud de lámina de hoja central, número de entrenudos y longitud de entrenudo central. Para producción incluyeron: producción de materia seca (MS), tasa absoluta de crecimiento y relación hoja: tallo. Los datos se analizaron mediante un diseño completamente al azar, incluyendo a los 16 ecotipos y comparación de medias con Tukey (p< 0.05). En todos los materiales se observaron diferencias significativas (p< 0.01) entre variables morfológicas y productivas. Los materiales sobresalientes para producción de MS fueron Elefante Tamps y Caña africana, con producción de (60.9 y 57.3 Mg MS ha-1); asimismo, para tasa absoluta de crecimiento: 338.5 y 318.5 kg MS ha-1 día-1). Estos ecotipos constituyen una excelente alternativa para su utilización en los diferentes sistemas de producción de carne y leche en las áreas tropicales de México; lo anterior, bajo un corte a 180 días de rebrote en el estiaje.

Arid and semi-arid areas are highly productive ecosystems that have a great diversity of species, among which grasses stand out. These species have ecological, environmental, and economic importance. The objective was to identify the ecological descriptors of 15 native species of grasses and diversity patterns through multivariate analysis techniques (principal component analysis, PCA, and cluster analysis, CA), in addition to identifying potential distribution areas (current and future) and regions of high and low diversity from 3841 accessions and 21 climatic variables. Among the main results, the extreme values, coefficient of variation, and median for each species could be determined. PCA determined that, with 10 variables, it was possible to explain 54.36% of the variation between the analyzed species. CA resulted in the formation of four statistically significant groups, with specific climatic characteristics. Regarding potential distribution areas and climate change, a reduction in distribution is expected (2050) on most of the current surface, with a possible opportunity zone in the north of the country. Finally, two hotspots (high diversity areas) and four coldspots (low diversity areas) were identified among the analyzed species. These results can be used to create strategies for sustainable use and the conservation of these resources.

Morphology and forage productivity of 25 Tripsacum spp. materials were characterized under tropical conditions in Nayarit, Mexico. Treatments included: Tripsacum latifolium, T. australe var. Australe, Tripsacum spp., T. dactyloides (cv. Meridionale and Hispidum), T. bravum, T. manisuroides, T. zopilotense, T. andersonii, T. lanceolatum, T. floridanum, T. laxum, T. cundinamarceae, T. intermedium, T. maizar, and T. peruvianum. Five in row equidistant plants (1.5 m) and three rows (replicates) per species, were evaluated and fertilized using 100-60-00 (N-P-K units) per hectare per year. Variables included: plant mean height, leading flowered stem’s height, plant crown circumference, basal cover, tillers per crown, forage yield and growth rates. Data was analyzed through a completely randomized design including 25 treatments (species, varieties, and/or ecotypes) and LSD tests for mean separation. Differences (p < 0.01) were observed among morphological, productive variables, and species. Outstanding material included T. latifolium and T. australe (8.3 and 5.6 kg DM per plant). Forage production ranged (p < 0.01) from 22% to 1405%, in comparison with the local ecotype T. dactyloides. Morphology and forage productivity within Tripsacum is highly variable, according to the genetic diversity available within this native to Mexico genus, suggesting that Tripsacum agamic complex presents enormous forage production potential for its promotion under grazing for rain-fed systems.

Forage grasses are an important component of livestock systems due to their contribution to animal feed, soil conservation, and carbon sequestration. In the face of climate change, analyzing stomatal characteristics allows us to understand the mechanisms of adaptation and tolerance to environmental stress. Therefore, the objective of this study was to determine the stomatal characteristics and trichome density of ten forage grasses present in a pine-oak dominated ecosystem. Sampling was carried out in October and November 2022 on a 1938 ha area. Mature, healthy leaves were selected, and epidermal impressions were obtained from the adaxial and abaxial surfaces using the cyanoacrylate method. Observations were made with an optical microscope at 400× magnification, quantifying stomatal density, trichome density, number of epidermal cells, and stomatal index per mm². The results indicated that nine species were amphistomatic, while Schizachyrium scoparium exhibited an epistomatic pattern. Muhlenbergia arizonica showed the highest stomatal density, and Setaria parviflora the lowest. It is concluded that there is high stomatal variability among species, highlighting its importance for the management and improvement of pastures.