scholarly journals Relationship between the morphogenesis of Italian ryegrass cv. 'BRS Ponteio' with forage and seed production

2015 ◽  
Vol 46 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Ricardo Pereira da Cunha ◽  
Carlos Eduardo da Silva Pedroso ◽  
Andréa Mittelmann ◽  
Roberto Caetano de Oliveira ◽  
Alberto Bohn ◽  
...  

This study aims to verify, accurate and precisely, the responses of Italian ryegrass 'BRS Ponteio' cultivar to different frequencies of defoliation for forage production and especially for seed production. For this purpose, a randomized block design experiment with four replications was conducted. Four frequencies of defoliation were applied (zero, one, two, and three) based on the thermal sum, evaluating the rate of leaf appearance (LAR), phyllochron (P), leaf expansion rate (LER), leaf senescence rate (LSR), stems expansion rate (SER), tillering rate (TR), leaf life span (LL), forage production, proportion of leaf blades, stems plus sheaths, senescent material, and inflorescences, as well as seed production. Second defoliation noticeably altered the morphogenic plant responses, reduced expansion rates and leaf appearance, increased rates of tillering and stems expansion. This phenotypic maintained a high seed production and provided a harvest of forage mass 100% higher than the collected mass in the first cutting. Third defoliation led to an increase of 100% of the harvested forage mass; however, it caused drastic and negative changes in the morphogenic characteristics and seed yielding.

2018 ◽  
Vol 19 (0) ◽  
Author(s):  
Francisco Migliorini ◽  
André Brugnara Soares ◽  
Daniel Schmitt ◽  
Laíse da Silveira Pontes ◽  
Tangriani Simioni Assmann

Abstract The aim of this study was to evaluate some morphogenetic and structural characteristics to explain variations in forage accumulation of Alexandergrass (Urochloa (Syn. Brachiaria) plantaginea) under continuous stocking method. The experimental treatments consisted of four grazing heights (10, 20, 30, and 40 cm), allocated to experimental units following a randomized block design with three replicates. The following variables were analyzed: leaf appearance, elongation, and senescence rates, leaf lamina length, number of leaves per tiller, leaf area index (LAI), and forage accumulation rate. Data were submitted to analysis of variance and means were compared by Student's t-test (P≤0.05). The main results were: i) different grazing heights had different tissue flows; ii) grazing heights between 30-40 cm showed the highest LAI, and produced similar values; iii) forage accumulation rate increased according to grazing height increments, but did not change above 30 cm. In conclusion, Alexandergrass pastures under continuous stocking should not be maintained at grazing heights lower than 30 cm if the objective is to maximize forage production.


2017 ◽  
Vol 38 (6) ◽  
pp. 3681 ◽  
Author(s):  
Nelson Eduardo Prestes ◽  
Cassandro Vidal Talamini do Amarante ◽  
Cassiano Eduardo Pinto ◽  
Gabriel Avila Prestes ◽  
Guilherme Doneda Zanini ◽  
...  

Natural pastures are important ecosystems that both contribute to biodiversity conservation and provide an important source of income, especially for cattle ranchers. While these pastures yield fairly low productivity, they can be improved by increasing soil fertility and introducing species with high productive potentials. In this sense, the purpose of this study was to evaluate the effects of applying limestone and phosphorus, as well as introducing cool-season species with a mixture of species dominated by Schizachyrium tenerum Nees, into a natural pasture in the Catarinense Plateau. The experiment was conducted from January 2010 to December 2013; the treatments consisted of superficial distribution of limestone in proportions of 3.6, 7.2, 11.0, and 14.4 t ha-1, as well as distribution of phosphorus in the form of triple superphosphate in proportions of 35, 70, 105, and 140 kg of P2O5 ha-1. In addition, cool-season species were overseeded. The experiment consisted of a randomized block design with subdivided plots and three replications. Limestone was applied to the main parcel, whereas phosphorus was applied to the subplots. There was no interaction between the levels of limestone and phosphorus. The application of 11.0 t ha-1 of limestone yielded the highest forage production, with 3,932.2 kg of dry matter (DM) ha-1 during the second year. Red clover was the species that best reacted to the additions, with levels of 7.2 and 11.0 t ha-1 over the 4 years. In addition, phosphorus provoked a positive response throughout the experiment. The highest forage production was observed during the second year, with an addition of 140 kg P2O5 ha-1 (4,419.4 kg DM ha-1). Only one-eighth of the recommended amount of limestone (3.6 t ha-1) allowed for the establishment and persistence of the legumes introduced into natural pastures. These additions, associated with increasing levels of phosphorus, yielded linear growth in the production of forage in natural pastures with a mixture of species dominated by Schizachyrium tenerum Nees.


2015 ◽  
Vol 45 (11) ◽  
pp. 2056-2062 ◽  
Author(s):  
Cezar Wankura Barbieri ◽  
Fernando Luiz Ferreira de Quadros ◽  
Felipe Jochims ◽  
Bruno Castro Kuinchtner ◽  
Thiago Henrique Nicola de Carvalho ◽  
...  

It was evaluated the effect of two rest intervals between grazing occupations in rotational grazing; 375 and 750 DD (degree-days); based on the cumulative thermal sum necessary for leaf expansion of native grasses of two functional groups over the grazing behavior variables from beef heifers with 12 months old. The experiment was conducted as a completely randomized block design, with two treatments, three replications and measures repeated over time. Grazing behavior was assessed in three occasions (Nov 2011, Jan and Mar 2012), with 24h each. The herbage intake was estimated using an external marker (Cr2O3). The leaf mass was similar among the rest intervals, with a mean of 1261kg DM ha-1. The average grazing time was 627.4min day-1 and bite rate was 37.1 bites min-1. The average number of daily meals was 5.9 with an average of 118.5 minutes. Number of feeding stations visited per minute was 6.1 and the feeding stations permanence time was of 12 seconds. There was a reduction only on grazing time and bite rate over the periods. The range of thermal sums evaluated to define the rest intervals in rotational grazing proved no effect on heifers' grazing behavior and herbage intake


2020 ◽  
Vol 50 (9) ◽  
Author(s):  
Alfredo Junior Paiola Albrecht ◽  
Leandro Paiola Albrecht ◽  
André Felipe Moreira Silva ◽  
Romulo Augusto Ramos ◽  
Natália Buttini Corrêa ◽  
...  

ABSTRACT: Conyza spp. is among the main weeds reported worldwide. Due to its aggressiveness, such as high seed production and dispersion, and the growing reports of biotypes resistant to glyphosate, paraquat, and other herbicides, different control practices are required. Thus, this study aimed to evaluate the efficacy of herbicides with sequential application of glufosinate in soybean pre-sowing for control of Conyza spp. with indicative of resistant to paraquat. The study was carried out in the field, at Assis Chateaubriand and Palotina, state of Paraná, Brazil, in the 2018/19 season. The experiments were conducted in a randomized block design with four replications. The treatments consisted in application of glyphosate, 2,4-D, saflufenacil, glufosinate, saflufenacil/imazethapyr, diclosulam, paraquat/diuron, paraquat and imazethapyr/flumioxazin, at different combinations, in soybean pre-sowing. Control of Conyza spp., crop injury to soybean plants and variables related to agronomic performance (plant height and yield) were evaluated. All treatments were selective for soybean, which showed stronger crop injury in the presence of diclosulam herbicide, but this did not compromise soybean agronomic performance. In general, control levels were high for the treatments used. Except for paraquat treatments, in the area with the highest frequency of Conyza spp. with indicative of resistant to paraquat, and imazethapyr/flumioxazin treatment in both areas. These control results emphasized the importance of glufosinate in this management system and showed promising results for saflufenacil/imazethapyr.


Weed Science ◽  
1999 ◽  
Vol 47 (6) ◽  
pp. 720-728 ◽  
Author(s):  
David W. Clausnitzer ◽  
Michael M. Borman ◽  
Douglas E. Johnson

Two field experiments were conducted from 1993–1994 through 1995–1996 growing seasons in Harney County, OR, to determine the relative competitive abilities ofElymus elymoides(squirreltail) a native perennial range grass, andTaeniatherum caput-medusae(medusahead), an exotic annual grass weed. The 1993–1994 growing season was very dry, 1994–1995 was dry, and 1995–1996 was wetter than average. One experiment tested seedlings vs. seedlings in each of three seasons. The second experiment tested seedlings plus second- and third-year establishedE. elymoidesplants vs. 77caput-medusaeover 2 yr. Biomass, seed production, and soil moisture utilization 15, 30, 45, and 60 cm deep by the two species were measured. A randomized block design with factorial arrangement was used, with 25 2.25-m2plots per block. Initial seeding densities of each species were 0, 10, 74, 550, and 4,074 seeds m−2in all combinations of density. In the seedling vs. seedling experiment, intraspecific competition by 77caput-medusaeon itself was always significant (P ≤ 0.10) for both biomass and seed production. Interspecific competition byE. elymoidesseedlings onT. caput-medusaebiomass and seed production was not significant (P ≥ 0.10) in 2 of 3 yr and was always less than intraspecific competition by 77caput-medusae. Only 0.4% ofE. elymoidesseed germinated, and no seed was produced in the very dry first year, but 84% of remaining seed was viable for the next year, which had better moisture conditions for germination and establishment. Interspecific competition affected (P ≤ 0.10)E. elymoidesseedling biomass and seed production throughout the study. Intraspecific competition affected (P ≤ 0.10) seedlingE. elymoidesseed production in the dry year but not in the wetter than average year. In the matureE. elymoidesexperiment, intraspecific competition byT. caput-medusaeon weight and seed production per plant was greater than interspecific competition fromE. elymoides. Seedling/matureE. elymoidesreducedT. caput-medusaeweight per plant in the dry year but the effect was not biologically significant. Larger, matureEelymoidesplants produced 600 to 3,000 seeds per plant during the wet year; neither intra- nor interspecific competition was a factor.Taeniatherum caput-medusaewas better able to access deeper soil moisture and was more aggressive at extracting soil moisture than wereE. elymoidesseedlings in the wet year. Cold soils and low oxygen due to wet soils may have restrictedE. elymoidesseedling root activity. MatureE. elymoidesplants did not appear restricted by cold soils or low oxygen. Established second- and third-yearE. elymoidesplants were able to compete for soil moisture down to 45 cm. The generally greater interspecific competitive effects ofT. caput-medusaeonE. elymoidesthan vice versa suggested that it will be difficult to establish anE. elymoidesstand in an existingT. caput-medusaecommunity without first suppressingT. caput-medusae. IndividualE. elymoidesplants did establish and were productive with and withoutT. caput-medusaecompetition.


2020 ◽  
pp. 1072-1080
Author(s):  
Charles Barbosa Santos ◽  
Kátia Aparecida de Pinho Costa ◽  
Wender Ferreira de Souza ◽  
Alessandro Guerra da Silva ◽  
Victor Costa e Silva ◽  
...  

Intercropping systems have become an interesting alternative for grain and forage production because they are sustainable systems that reduce carbon emissions in degraded pasture areas. However, few studies have used forage species recently introduced into the market, and more studies that assess the performances of these species in integrated systems are needed. Therefore, the objective of this study was to evaluate the agronomic characteristics of intercropped sorghum and Paiaguas palisadegrass (including the species name) in a crop-livestock integration system for pasture recovery. The field experiment was conducted in the municipality of Rio Verde, Goiás, Brazil, using a randomized block design with four replications. The treatments consisted of the following forage systems: monocropping of sorghum, monocropping of Paiaguas palisadegrass, row intercropping of sorghum with Paiaguas palisadegrass, interrow intercropping of sorghum with Paiaguas palisadegrass and intercropping of sorghum with oversown Paiaguas palisadegrass. To obtain a desired population of 240,000 plants ha-1, 12 seeds of sorghum and 5 kg of viable pure seeds of the forage species were planted per meter and hectare, respectively. The growth of Paiaguas palisadegrass in the same row as sorghum reduced the sorghum grain yield. The intercropping of sorghum with oversown Paiaguas palisadegrass hindered the initial development of Paiaguas palisadegrass in terms of plant height and number of tillers due to shading, and this effect was reflected in the dry mass production. Row and interrow intercropping provided higher dry mass production without affecting the forage quality. Therefore, the interrow intercropping of sorghum with Paiaguas palisadegrass was found to be a promising agricultural technique for grain and forage production that could be used for the establishment of new pastures or pasture recovery.


2018 ◽  
Vol 39 (6) ◽  
pp. 2517
Author(s):  
Armindo Neivo Kichel ◽  
Luis Carlos Ferreira de Souza ◽  
Roberto Giolo de Almeida ◽  
José Alexandre Agiova da Costa

This study aimed to assess productivity and nutritional value of the tropical grasses Brachiaria brizantha cv. Piatã, Xaraés, and Marandu, Panicum maximum cv. Mombaça, and B. ruziziensis cv. Kennedy in the interseason of an integrated crop-livestock (ICL) system since alternatives are needed for forage production for animal grazing in Autumn and Winter. The experimental design was a randomized block design in a split-split plot scheme with four replications. The treatments of plots consisted of five grasses, subplots consisted of three cropping systems (monoculture, intercropping with corn and unsuppressed grass, and intercropped with corn and suppressed grass), and sub-subplots consisted of four cutting intervals of grasses (50, 90, 125, and 195 days after emergence - DAE). The experiment was carried out from February to September 2014. Dry matter (DM) productivity, obtained at 195 DAE for the three cropping systems (monoculture grass, unsuppressed and suppressed grass in intercropping), were 18.45, 7.15, and 3.05 t ha?1, respectively, and average crude protein contents of leaf blades of grasses decreased linearly between the cutting intervals of 50 to 195 DAE from 19.95 to 9.70%, respectively. Under integrated systems, the studied grasses showed better yields and nutritional quality when compared to traditional grazing systems. Panicum maximum cv. Mombaça and Brachiaria brizantha cv. Xaraés and Piatã had the highest leaf and crude protein yields when compared to Brachiaria ruziziensis cv. Kennedy and Brachiaria brizantha cv. Marandu. In terms of nutritional value, Brachiaria ruziziensis cv. Kennedy was superior to Mombaça and Xaraés grasses but had lower total dry matter yield. Finally, Xaraés, Piatã and Mombaça grasses are recommended choices ICL systems when fodder grass production is the goal.


2017 ◽  
Vol 38 (5) ◽  
pp. 3271
Author(s):  
Márcio Odilon Dias Rodrigues ◽  
Antonio Clementino dos Santos ◽  
Marcos Odilon Dias Rodrigues ◽  
Rubens Ribeiro da Silva ◽  
Otacilio Silveira Junior

This study aimed to evaluate the effect of nitrogen (N) fertilizer doses on morphogenic and structural characteristics of mombassa grass (Panicum maximum Jacq.) at three different periods of the lifespan of tillers. The experiment was conducted in Araguaína-TO, Brazil, from December 2014 to February 2015. It was installed in split plots in a randomized block design with four replications. The doses of N-fertilizer (0, 30, 60, 90 kg N.ha-1) were the plots and the periods evaluated (1PER – first period from day 16 to 30; 2PER from day 31 to 45 and 3PER from day 46 to 60 after germination) were the subplots. The evaluated variables consisted of leaf appearance rate (LAR), leaf elongation rate (LER), stem elongation rate (SER), leaf senescence rate (LSR), phyllochron, tiller number, leaf emergence, and total leaf number. A Pearson correlation analysis was used to morphogenic and structural characteristics along with a regression analysis for all the variables. Overall, increasing N-fertilizer doses positively influenced the leaf appearance and leaf elongation rates, tiller density, and the number of live leaves per tiller. The 90-kg N.ha-1 dose enabled the best morphogenic and structural responses of the forage when compared to the other rates. Each period featured differently, with higher values of LSR, SER, and LER in 3PER when compared to those in 2PER and in 1PER. Therefore, the nutritional supply over the first weeks of tiller lives was defining to an increase in forage production in the remaining periods. In light of this, we observed that as LAR raise in the first days after germination, nutritional supplies are required from day 15 on, mainly nitrogen, so plants could continue their development since initial plant growth determines pasture productive vigor and longevity.


Weed Science ◽  
2016 ◽  
Vol 64 (4) ◽  
pp. 683-694 ◽  
Author(s):  
Alberto Collavo ◽  
Silvia Panozzo ◽  
Antonio Allegri ◽  
Maurizio Sattin

Italian ryegrass populations investigated in this study were harvested in an alfalfa-based cropping system. In that system, the agronomic practices and chemical weed management, based on the use of aryloxyphenoxy-propionates herbicides (i.e., quizalofop ethyl ester), were optimized to obtain a dual seed–forage production. Five of seven populations tested were confirmed resistant to quizalofop ethyl ester with resistance indexes ranging from 4.5 to >209. Both target- and nontarget-site resistance mechanisms were most likely involved. Three allelic variants were detected (Ile-1781–Leu, Trp-2027–Cys, and Ile-2041–Asn) in four resistant populations, whereas no known mutations were found in one resistant population. The herbicide treatment on Italian ryegrass plants at different phenological stages suggested that to control regrowth, it is necessary to use two to fives times the herbicide dose suitable for younger plants. This situation is encountered in fields when Italian ryegrass plants need to be controlled to maximize the alfalfa seed production, and it is comparable to using a sublethal herbicide dose, leading to the selection of herbicide-resistant biotypes. In such a situation, the cropping system is not sustainable, and integrated weed management should be implemented to deplete the soil weed seed bank and prevent new weed seed production.


2019 ◽  
Vol 12 (1) ◽  
pp. 84
Author(s):  
Carlos Augusto Oliveira de Andrade ◽  
Emerson Borghi ◽  
Leandro Bortolon ◽  
Elisandra Solange Oliveira Bortolon ◽  
Francelino Peteno de Camargo ◽  
...  

Brazil is one the largest soybean and cattle producer worldwide and degrade pasture is one of the major problem in the Cerrado region. Integrated crop-livestock system is a key to increase grower income, to reduce crop yield loss by water deficit during growing season and to reclaim degraded pasture. However, forage production and its quality is important to evaluate under integrated crop-livestock system. The objective of this study was to evaluate forage production and the bromatological composition of different forage species in monoculture and in intercropping with soybean in an oversowing system. A completely randomized block design with four replications in a 5 × 2 + 1 factorial scheme, with five forage species (Urochloa brizantha cv. Marandu; U. ruziziensis; P. maximus cv. Mombaça; P. infestans cv. Massai and P. americanum) and two cropping systems (monoculture and a consortium with soybeans) and a standard treatment (P. americanum in succession with soybeans). The forage productivity and the bromatological composition of the forages were evaluated. The species U. ruziziensis, U. brizantha, M. maximum and P. infestans presented higher forage production capacity, when cultivated in consortium with soybeans and in monoculture, in relation to P. americanum. The cultivation of the forages U. ruziziensis, U. brizantha, M. maximum and P. americanum in monoculture produced higher productivity than that in consortium with soybeans. The forages U. ruziziensis and U. brizantha intercropped with soybean presented a better nutritional value over the autumn-winter period.


Sign in / Sign up

Export Citation Format

Share Document