Author: ALFONSO HERNANDEZ GARAY
The objective of this paperwas to study the effect of yield of Brachiaria humidicola cv Chetumal grass at different frequencies and intensities of grazing. The cutoff frequencies of 21 and 28 d and the intensities of 9-11 and 13-15 cm were evaluated, which were randomly distributed in a random block design with 2*2 factorial arrangement
with three replicates. Management effects on dry matter accumulation were observed, with accumulation at lower
frequency and light grazing intensity being greater. Forage production had a seasonal distribution of 66, 26 and 7% in
the rainy season, north and dry seasons, respectively. The leaf ratio in harvested forage was 20, 30 and 86% for north,
dry and rainy seasons, respectively.
The objective of this study was to evaluate two seed sizes in the physiological quality of orchard grass and perennial ryegrass (Dactylis glomerata L., Lolium perenne L.). The treatments were two sizes of seed (large:LS and small:SS). The variables were: emergence (EM), abnormal seedlings (AS), non-germinated seeds (NGS), establishment (ES), viability (VI), speed of emergence (SE), seedling height (SH), and root length (RL). A CRD with 4 repetitions were used. It was observed that, regardless of the size, the EM was higher in perennial ryegrass (p¿0.05), compared to orchard
grass, due to it presenting the highest (p¿0.05) percentage of AS and NGS.
The objective of this research was to evaluate four associations of two grass and a legumein different percentages. Sowing was done in February 2010, in the Graduate College, Campus Montecillo, Mexico; based on the densities of 20, 30 and 5 kg ha-1 for orchard grass (Ov), perennial ryegrass (Ba) and white clover (Tr), respectively. Treat ments consisted of the following associations: 20-40-40, 00-50-50, 40-20-40, 50-00-50% Ov, Ba and Tr. The four treatments were randomly distributed in 12 experimental plots of 9 by 8 m according to a design of a randomized complete block with three replications. The association 50-00-50 of Ov-Ba-Tr is the one with greater density orchard grass stalks
with an average of 4,250 m2 stems, and lower the association 20-40-40 of Ov-Ba-Tr with an average of 3,400 m2
stems (p = 0.05).
Seven associations were evaluated, two grasses and legume planted in different proportions and a monoculture (orchard grass). The research was conducted from september 2012 to september 2014 in the Graduate College, Campus Montecillo, Mexico. The restriction to the legume was 10 and 50% minimum and maximum, respectively. Treatments consisted of the following associations: 20-40-40, 00-50-50, 40-20-40, 50-00-50, 20-70-10, 70-20-10,100-00-00, 40-40-20% of skein (Ov), ryegrass (Ba) and white clover (Tr), respectively. The treatments were randomized in 24 experimental plots of 9 and 8 m, according to a design of a randomized complete block with three replications.
Associations that presented the highest growth rate in two years were; 20-70-10, 20-40-40 and 40-20-40 with an
average of 57 kg MS ha-1 d-1, and the lowest growth rate monoculture skein (100-00-00) with 32 kg MS ha-1 d-1 (p<
Se evaluó el pasto ballico perenne (Lolium perenne L.) en monocultivo y cuatro asociaciones con pasto ovillo (Dactylis glomerata L.) y trébol blanco (Trifolium repens L.) en diferentes proporciones para maximizar el rendimiento de materia seca. Las proporciones en monocultivo y las asociaciones de ballico perenne, ovillo y trébol blanco fueron: 100:00:00, 70:20:10, 50:00:50, 40:40:20 y 20:70:10, las cuales se distribuyeron bajo un diseño de bloques completamente al azar con tres repeticiones. Se evaluó el rendimiento de materia seca, composición botánica y morfológica, relación hoja:tallo y densidad de plantas. La asociación 50:00:50 superó 15% (3 671 kg MS ha-1) a la asociación 70:20:10.El ballico perenne contribuyó más al rendimiento de materia seca en otoño e invierno, mientras que el ovillo y trébol blanco en primavera y verano.
The objective of this research was to evaluate tiller population of orchard grass seeded with perennial ryegrass and white clover in different proportions and single. Treatments consisted of the associations: 20-70-10, 70-20-10, 100-00-00, 40-40-20 % of orchard grass (OG), perennial ryegrass (RG) and white clover (WT) respectively. Treatments were distributed in a randomized complete block with three replications. The association 70-20-10 of OG-RG-WT had greatest tiller density of OG with an average of 3,750 tiller m-2, and the lowest in 100-00-00 with an average of 2,400 tiller m-2 (P<0.05).
The objectives of the study were to perform the fodder accumulation curves and morphological components and light
interception to determine the optimal moment of cutting for green fodder of three lines and one wheat variety (Triticum sp.). Harvests were performed at intervals of 7 d, 43 days after sowing (DAS). In each harvest the average height of 20 plants was recorded, the intercepted radiation (IR), dry matter accumulation, morphological composition, and leaf area index (LAI). The sampling unit was a square of 0.45 m2.
Alfalfa (Medicago sativa L.) is the most commonly used legume forage in the diet of dairy cattle in the United States
and Mexico. The objective of this research was to evaluate the productive response of five alfalfa varieties with defined
cutting intervals seasonally. The research was conducted from June 2010 to June 2011 in the Colegio de Postgraduados, Mexico. Commercial varieties evaluated were: San Miguelito, Jupiter, Atlixco, Via lacteal and Cuf 101, which were randomly distributed into 20 experimental plots of 12 x 9 m, according to a randomized complete block with four replications. The variables evaluated were: growth rate, intercepted radiation, leaf area index and plant height. Jupiter and Cuf 101 varieties with 56 and 37 kg DM ha-1 d-1 recorded the highest and lowest growth rate, respectively.
ADELAIDO RAFAEL ROJAS GARCIA MARIA DE LOS ANGELES MALDONADO PERALTA PAULINO SANCHEZ SANTILLAN SERGIO IBAN MENDOZA PEDROZA PERPETUO ALVAREZ VAZQUEZ JERONIMO HERRERA PEREZ ALFONSO HERNANDEZ GARAY (2018)
Ruminant production in the tropics is based primarily on native and introduced grass (Poaceae) grazing. The effect of the regrowth age and cutting intensity of Brachiaria hybrid cv Cobra grass was evaluated, and the nutritional value when varying the frequency and intensity of 10 and 15 cm of cutting in the dry season. The study period was from January 19 to March 30, 2017. The variables were dry matter yield, morphological composition, raw protein (RP), neutral detergent fiber (NDF), and acid detergent fiber (ADF). The highest yield was obtained after 56 days in the intensity of 15 cm with 2550 kg MS ha¿1; however, the highest volume of leaves was reached at 35 days with 1200 kg MS ha¿1. The maximum content of Cobra grass RP was in the frequency at seven days with 19.3% in the leaf
component, decreasing as the evaluation time went by. The NDF and ADF content increased with the age of the regrowth.
Alfalfa (Medicago sativa L.) is the most important legume forage for dairy cattle feed in Mexico. The objective of this
study was to assess the productive response of five varieties of alfalfa in cutting intervals defined seasonally. Our hypothesis was that the San Miguelito variety is the most productive among the evaluated varieties. The varieties San Miguelito, Júpiter, Atlixco, Vía láctea and Cuf 101 were randomly distributed in 20 experimental plots of 12¿9 m, in a
completely randomized blocks design with four replications. Evaluations included yield feed, leaf:stem ratio, weight per
stem, stem population per m2, plant population per m2 and botanical and morphological composition. Júpiter and Cuf
101 showed the highest yield (20 275 and 13 350 kg MS ha¿1). Leaf:stem ratio was higher in Cuf 101 and smaller in Júpiter. The weight per stem was higher in Júpiter and lower in Cuf 101.