scholarly journals Uso de retenedores de humedad edáfica en la sobrevivencia y crecimiento de dos especies de pastos Bouteloua curtipendula [Michx.] Torr. y Chloris gayana Kunth

2018 ◽  
Vol 9 (4) ◽  
pp. 703-718
Author(s):  
Luis Gerardo Yáñez-Chávez ◽  
Aurelio Pedroza-Sandoval ◽  
Martín Marínez-Salvador ◽  
Ignacio Sánchez-Cohen ◽  
Francisco Guadalupe Echavarría-Cháirez ◽  
...  
Keyword(s):  
Bouteloua Curtipendula ◽  
Chloris Gayana ◽  
Chloris Gayana Kunth

El 85 % de las zonas áridas y semiáridas de México presentan problemas de erosión por sobrepastoreo en áreas de pastizal, con el consecuente incremento en el proceso de desertificación de los suelos. El objetivo del presente estudio, fue evaluar diferentes especies y prácticas de retención de humedad en el suelo en el establecimiento y desarrollo de pasto en zonas semiáridas. Se usó un diseño experimental de bloques al azar en un arreglo de parcelas divididas con tres repeticiones. Las parcelas grandes correspondieron a las dosis de rastrojo de maíz (0 y 10 t ha-1), las parcelas medianas a las dosis de hidrogel (0, 10 y 20 kg ha-1) y las parcelas chicas a las dos especies de pastos Bouteloua curtipendula [Michx.] Torr. y Chloris gayana Kunth. Se usó el método de trasplante. El porcentaje de sobrevivencia fue superior a 72 % en promedio general, aun cuando B. curtipendula fue sobresaliente en las diferentes fechas de evaluación. El rastrojo de maíz como cobertura vegetal, registró un contenido de humedad en el suelo de 16.9 % en relación al testigo, con el consecuente aumento de 24.9 % en la producción de biomasa en términos de materia seca. Lo anterior se asoció a plantas con mayor altura, un mayor número de macollos y un mayor contenido de clorofila. El hidrogel, sólo influyó durante los primeros 15 días después del trasplante al inicio de elongación, con un mejor porcentaje de sobrevivencia después del trasplante de los pastos; sin ningún efecto en fechas posteriores durante la fase de crecimiento y desarrollo del pasto.

scholarly journals GERMINACIÓN Y EMERGENCIA DIARIA DE CARIÓPSIDES Y DIÁSPORAS DE PASTOS NATIVOS E INTRODUCIDOS

2017 ◽  
Vol 40 (1) ◽  
pp. 35-44
Author(s):  
Adrián R. Quero-Carrillo ◽  
Filogonio J. Hernández-Guzmán ◽  
Paulino Pérez-Rodríuez ◽  
Duane Pool ◽  
Patricia Landa-Salgado ◽  
...  
Keyword(s):  
Cenchrus Ciliaris ◽  
Bouteloua Curtipendula ◽  
Chloris Gayana ◽  
Chloris Gayana Kunth

El objetivo del presente trabajo fue evaluar la tasa de germinación diaria (TGD) en cariópsides clasificados por tamaño (CCT) y la tasa de emergencia diaria (TED) tanto en CCT como en diásporas, en los pastos nativos Banderita (Bouteloua curtipendula (Michx.) Torr.) y Navajita (B. gracilis (Willd. ex Kunth) Lag. ex Griffiths), y los introducidos Buffel (Cenchrus ciliaris L.) y Rhodes (Chloris gayana Kunth). Se obtuvieron cariópsides a partir de diásporas y se clasificaron en chicos, medianos y grandes, y todos los propágulos se sometieron a: 1) Pruebas de envejecimiento acelerado (PEA), durante 12, 24 y 36 h a 42 ºC y 100 % de HR. Se sembró a cariópsides sobre papel y a diásporas en Peat Moos a 1 cm de profundidad y se cuantificó la aparición de plántulas normales durante 15 d y; 2) Se sembraron los dos propágulos por especie de pasto a 0.5, 1.0, 2.0, 3.0 y 5.0 cm de profundidad (PS) en suelos Vertisol y Calcisol y se cuantificó la emergencia durante 64 d. La información se analizó con el procedimiento LIFEREG de SAS (α = 0.05). Se observó diferencia en TGD y TED después de PEA para pastos nativos e introducidos (P ≤ 0.001). Las TGD mayores en Banderita, Navajita, Buffel y Rhodes fueron a mayor tamaño de cariópside y sin estrés y se concentró a 2 d después de siembra (dds) mientras en diásporas, en nativos, fueron a menor estrés de 4 a 6 dds y en pastos introducidos a menor estrés, en Buffel, se concentró de 6 a 12 d y en Rhodes de 5 a 8 d. En cuanto a PS, la mayor TED para las especies estudiadas en cualquier tipo de propágulo, se registró entre 0.5 y 3.0 cm de PS y, suelo tipo Vertisol mostró mayores TED. Sembrar cariópsides de mayor tamaño reduce el periodo de emergencia de plántulas, lo cual es importante para establecer más plantas por m2 en temporal semiárido.

Effects of flood irrigation and plant growth on two riverine soils

1959 ◽  
Vol 10 (4) ◽  
pp. 510 ◽  
Author(s):  
KP Barley ◽  
AL Tisdall
Keyword(s):  
Plant Growth ◽  
Exchangeable Sodium ◽  
Flood Irrigation ◽  
Nitrogen And Phosphorus ◽  
Rhodes Grass ◽  
Water Stable Aggregates ◽  
Electrolyte Content ◽  
Chloris Gayana ◽  
The Stability ◽  
Chloris Gayana Kunth

Two soils which contained significant proportions of exchangeable sodium were frequently irrigated during summer with water of low electrolyte content. When all vegetation was removed the soils became very unstable in water. When the natural vegetation was left intact the stability and structure of the soils did not deteriorate despite frequent irrigation. When the amount of vegetation was increased by sowing Rhodes grass (Chloris gayana Kunth) and supplying nitrogen and phosphorus the stability of the soil increased. After 8 years' growth of Rhodes grass the top inch of soil contained 30–40 per cent. of water-stable aggregates greater than 1 mm in diameter, compared with a content of 10–20 per cent. in virgin soil. Thus, the protective effect of the organic matter added to the soil by plant growth more than compensated for aggregate disruption caused by flood wetting or by a reduction in electrolyte content of the soil solution.

A study of two strains of Rhodes Grass (Chloris gayana Kunth.) and of Leucerne (Medicago sativa L.) as components of a mixed pasture at Lawes in South-east Queensland

1952 ◽  
Vol 3 (3) ◽  
pp. 277 ◽  
Author(s):  
CS Christian ◽  
NH Shaw
Keyword(s):  
Medicago Sativa ◽  
Growth Form ◽  
Live Weight ◽  
Small Population ◽  
Rhodes Grass ◽  
Weight Gains ◽  
Chloris Gayana ◽  
Medicago Sativa L ◽  
Chloris Gayana Kunth

The results of investigations with Rhodes grass and lucerne as components of sown pastures at Lawes in south-east Queensland are reported. Two strains of Rhodes grass, differing very markedly in growth form, rate of maturity, and other characteristics, were shown to be virtually of the same value when grazed by cattle under a system of intermittent grazing at a heavy rate of stocking. It was shown that lucerne could be maintained in a mixed pasture with Rhodes grass, and that the presence of a small population of lucerne, of a density of 2-4 plants per square yard, resulted in Increased growth of Rhodes grass and increased live-weight gains by the steers. Reasons for these increases are discussed.It is considered that the mixture, which can be expected to give improved grazing mainly during the summer months, has possibilities for large areas in south-east Queensland.

Properties of Phosphoenolpyruvate Carboxykinase Operative in C4 Pathway Photosynthesis

1977 ◽  
Vol 4 (2) ◽  
pp. 207 ◽  
Author(s):  
MD Hatch ◽  
S Mau
Keyword(s):  
Phosphoenolpyruvate Carboxykinase ◽  
Reverse Direction ◽  
Nucleoside Triphosphate ◽  
Dihydroxyacetone Phosphate ◽  
C4 Pathway ◽  
Phosphoglyceric Acid ◽  
Michaelis Constants ◽  
Chloris Gayana ◽  
Fructose 1,6 Bisphosphate ◽  
Chloris Gayana Kunth

A procedure is described for partially purifying phosphoenolpyruvate carboxykinase [ATP : oxaloacetate carboxy-lyase (transphosphorylating), EC 4.1.1.49] from leaves of Chloris gayana Kunth. In three steps the enzyme was purified about 60-fold with 22% recovery of activity. This procedure removes enzymes, particularly malate dehydrogenase, that preclude the use of a simple spectrophotometric assay for phosphoenolpyruvate carboxykinase. The activity of the enzyme in the direction of oxaloacetate decarboxylation was about 10 times that in the reverse direction. At the optimal pH of 8.0, ATP was the preferred nucleoside triphosphate but CTP, UTP, GTP and ITP were also active. A requirement for Mn2+ could not be replaced by Mg2+. The Michaelis constants for oxaloacetate and ATP were 0.035 mM and 0.024 nM, respectively. The photosynthetic intermediates fructose 1,6-bisphosphate, 3-phosphoglyceric acid and dihydroxyacetone phosphate significantly inhibited the enzyme at concentrations in the region of 1-5 mM. Unlike the phosphoenolpyruvate carboxykinase from other sources, the capacity of the leaf enzyme to catalyse the decarboxylation of oxaloacetate to pyruvate was negligible. The properties of the enzyme are discussed in relation to its proposed role in C4 pathway photosynthesis.

Isotopic studies on the uptake of nitrogen by pasture plants. IV. Uptake of nitrogen from labelled plant material by Rhodes grass and Siratro

1968 ◽  
Vol 19 (1) ◽  
pp. 65 ◽  
Author(s):  
EF Henzell ◽  
AE Martin ◽  
PJ Ross ◽  
KP Haydock
Keyword(s):  
Plant Material ◽  
Mineral Nitrogen ◽  
Rhodes Grass ◽  
Significant Difference ◽  
Isotopic Studies ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Chloris Gayana ◽  
The Difference ◽  
Chloris Gayana Kunth

Rhodes grass (Chloris gayana Kunth.) and Siratro (Phaseolus atropurpureus D.C. var. Siratro) plants were grown separately and together in pots of soil containing 15N-labelled ground Rhodes grass plant material (carbon/nitrogen ratio 44). The added plant material immobilized nitrogen during the first 6 weeks of the experiment, and nitrogen uptake by Rhodes grass was still less than that of the control at 15 weeks. Both the grass and the nodulated legume took up 15N throughout the experiment, despite the reduction in availability of unlabelled soil nitrogen. Siratro grown alone took up as much 15N as Rhodes grass grown alone. When the plants were grown together about one-third of the 15N uptake went into the Siratro and two-thirds into the Rhodes grass. The Siratro roots had a higher 15N enrichment than the tops, indicating that relatively more of the unlabelled nitrogen fixed from the atmosphere went into the Siratro tops, compared with the labelled nitrogen taken up from the soil. With Rhodes grass the tops had a higher enrichment than the roots. The difference between the extractable mineral nitrogen in the pots of soil under grass and in the bare pots accounted for uptake by the grass at 3 weeks but underestimated it at 15 weeks. In addition, there was a significant difference in enrichment between the total extractable mineral nitrogen in the soil and the nitrogen taken up by the Rhodes grass. From the uptake and partition of 15N it was calculated that 43–50% of the nitrogen in the Siratro plants at 3 weeks was taken up from the soil (the rest was attributed to symbiotic fixation); at 15 weeks only 2–4% of the nitrogen in the Siratro was from the soil. Very little nitrogen was transferred from the Siratro to the associated Rhodes grass.

scholarly journals Effect of Nitrogen and Variety on Agronomic Performance of Rhodes Grass (Chloris gayana Kunth) in the Sudan

2020 ◽  
pp. 19-26
Author(s):  
Hussein H. A. M ◽  
Dagash Y. M. I ◽  
Maarouf I. Mohammed
Keyword(s):  
Plant Height ◽  
Nitrogen Fertilization ◽  
Science And Technology ◽  
Forage Yield ◽  
Agronomic Performance ◽  
Rhodes Grass ◽  
Split Plot ◽  
Chloris Gayana ◽  
Chloris Gayana Kunth ◽  
Plot Experiment

An experiment was conducted in Shambat (2016-2017) in the demonstration farm of the College of Agricultural Studies, Sudan University for Science and Technology, to study the effect of variety and nitrogen fertilization on the agronomic performance of Rhodes grass. Two Rhodess grass varieties (Fine cut and Reclaimer) and 2 nitrogen doses plus control were studied across seven cuts. The treatments were replicated four times in split plot experiment with fertilizer doses assigned to the main plots and the varieties to the sub-plots. The data collected included forage yield, plant height and days to 50% flowering.

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