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Nitrogen Or Water Limitation To Grassland Growth During A Moderate Dry Season In The Humid Tropics, P. Cruz, M. Boval Sep 2021

Nitrogen Or Water Limitation To Grassland Growth During A Moderate Dry Season In The Humid Tropics, P. Cruz, M. Boval

IGC Proceedings (1977-2023)

The aim of this work was to compare the effects of nitrogen and water shortage on grassland production during a moderate dry season in a tropical humid environment. The results of two experiments carried out in Guadeloupe (FWI) have shown that during dry spells, the reduction in growth of natural grasslands based on Angleton grass (Dichantium aristatum) is more easily corrected by nitrogen fertiliser application than by irrigation. This shows that it is not the availability of water, but that of nitrogen, which is limiting the primary production of Angleton grass, stands. This result is less clear for …

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Selection Of High Yielding And Anthracnose Resistant Stylosanthes For Brazil, India And China, N. White, S. Chakraborty, Celso D. Fernandes, M. J. Charchar, N. P. Melkania, C. R. Ramesh, B. Gangaiah, Guodao Liu, D. F. Cameron, J. W. Miles Sep 2021

Selection Of High Yielding And Anthracnose Resistant Stylosanthes For Brazil, India And China, N. White, S. Chakraborty, Celso D. Fernandes, M. J. Charchar, N. P. Melkania, C. R. Ramesh, B. Gangaiah, Guodao Liu, D. F. Cameron, J. W. Miles

IGC Proceedings (1977-2023)

Resistance to anthracnose, dry matter yield (DMY) and seed yield (SY) was assessed for germplasm and breeding lines of Stylosanthes in Brazil, India and China. Overall, Stylosanthes guianensis produced higher DMY than S. scabra, S. capitata and S. macrocephala at most sites in Brazil. Data from China suggest that there are high yielding anthracnose resistant S. guianensis lines that can reduce the reliance on CIAT 184. S. seabrana might also prove successful. S. seabrana in India produced the highest DMY and SY and it can form nodules with native Bradyrhizobium strains. Regional differences in resistance within accessions stress the …

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Genetic Diversity In The Anthracnose Pathogen Infecting Stylosanthes In Brazil, India And China, P. Weeds, S. Chakraborty, Celso D. Fernandes, M. J. Charchar, C. R. Ramesh, Guodao Liu, S. Kelemu Sep 2021

Genetic Diversity In The Anthracnose Pathogen Infecting Stylosanthes In Brazil, India And China, P. Weeds, S. Chakraborty, Celso D. Fernandes, M. J. Charchar, C. R. Ramesh, Guodao Liu, S. Kelemu

IGC Proceedings (1977-2023)

This work aimed to determine the genetic diversity of Colletotrichum gloeosporioides infecting Stylosanthes spp. in Brazil, China and India. A total of 132 isolate originating from S. seabrana, S. macrocephala, S. capitata, S. scabra, and S. guianensis were used. Four major genetic groups were identified from an analysis of genetic diversity using selection-neutral DNA markers. Group 1 contained 20 isolates and this may represent a genotype that migrated from the center of diversity in Brazil and Colombia to Australia, Thailand and India. Group 2 consisted of 66 Brazilian isolates and group 3 had 19 isolates from …

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Seasonal Patterns Of Growth And Senescence In Cynodon Spp. Cv Tifton 85 Grazed Swards, L. F. M. Pinto, L. G. Barioni, S. C. Da Silva Sep 2021

Seasonal Patterns Of Growth And Senescence In Cynodon Spp. Cv Tifton 85 Grazed Swards, L. F. M. Pinto, L. G. Barioni, S. C. Da Silva

IGC Proceedings (1977-2023)

Growth and senescence are very important determinants of grassland productivity and correspond to key features to be considered for grazing management purposes. The present study was carried out at ESALQ, Piracicaba, S.P., Brazil and evaluated growth and senescence as a function of sward surface height. Mathematical models generated revealed that a similar pattern of response occurred as described in the literature for temperate grass species. However, a seasonal variation in response curves for growth and senescence was also observed and could be related to climatic events. Highest herbage accumulation rates were observed within the range of 15 to 20 cm …

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Yields And Sward Characteristics Of Timothy Cultivars Under Grazing, H. T. Kunelius, G. H. Dürr, K. B. Mcrae, S. A. E. Fillmore Sep 2021

Yields And Sward Characteristics Of Timothy Cultivars Under Grazing, H. T. Kunelius, G. H. Dürr, K. B. Mcrae, S. A. E. Fillmore

IGC Proceedings (1977-2023)

Seven timothy (Phleum pratense L.) cultivars were evaluated over three pasture seasons under rotational grazing to 7 or 11 cm post-grazing heights and regrowth periods of four to seven weeks. There was a trend for the pasture type timothy cultivars to outyield Champ timothy (check). Dry matter yields were lower for the 7 cm than 11 cm post-grazing height. Although the overall cultivar x post-grazing height interaction was not significant (P > 0.05), there was variability in grazing tolerance among timothy cultivars. Yield of Kahu was maintained and vegetative tiller density of Kahu increased over the experimental period under 7 …

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Photosynthetic Light Response Of Tanzania Grass Under Four Levels Of Leaf Temperature, A. C. L. De Mello, P. M. Santos, Carlos G. S. Pedreira, M. Corsi, C. T. Dos S. Dias Sep 2021

Photosynthetic Light Response Of Tanzania Grass Under Four Levels Of Leaf Temperature, A. C. L. De Mello, P. M. Santos, Carlos G. S. Pedreira, M. Corsi, C. T. Dos S. Dias

IGC Proceedings (1977-2023)

The purpose of this paper is to establish photosynthetic light response curves for Tanzania grass (Panicum maximum Jacq.) under four leaf temperature levels. Photosynthetic rate was measured as a response to levels of photosynthetic photon flux density (PPFD) on the youngest fully expanded leaves of 12 representative tillers with an infra red gas analyzer. The effect of PPFD was tested for each leaf temperature level in a randomized complete block design. Photosynthetic light response curves were adjusted for each leaf temperature using a non-linear hyperbolic model. The maximum photosynthetic response was 25,59; 31,43; 34,57 and 27,53 µmol CO2 …

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Leaf Appearance Rate In Brachiaria Decumbens Grown In Nitrogen And Potassium Rates, M. D. C. Ferragine, F. A. Monteiro, S. C. Da Silva Sep 2021

Leaf Appearance Rate In Brachiaria Decumbens Grown In Nitrogen And Potassium Rates, M. D. C. Ferragine, F. A. Monteiro, S. C. Da Silva

IGC Proceedings (1977-2023)

A greenhouse experiment was carried out with Brachiaria decumbens Stapf. cv. Basilisk grown in nutrient solution. Five nitrogen rates (42; 140; 238; 336 and 434 mg/L) and three potassium rates (78; 234 and 390 mg/L) were studied in a factorial experiment, in a randomized complete block design, with four replications. Green leaf number was evaluated in six times in the first period of growth (27, 30, 33, 36, 39 and 42 days after transplanting) and nine times in the second period (45, 48, 51, 54, 57, 60, 63, 66 and 69 days after transplanting). Data was registered in three plants …

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Morphogenesis And Defoliation Frequency Of Italian Ryegrass (Lolium Multiflorum) And Paspalum Urvillei In Lowland Under Three Levels Of P And K, Fernando L. F. De Quadros, A. G. S. Pigatto, D. G. Bandinelli, E. Marchezan, Marta G. Da Rocha Sep 2021

Morphogenesis And Defoliation Frequency Of Italian Ryegrass (Lolium Multiflorum) And Paspalum Urvillei In Lowland Under Three Levels Of P And K, Fernando L. F. De Quadros, A. G. S. Pigatto, D. G. Bandinelli, E. Marchezan, Marta G. Da Rocha

IGC Proceedings (1977-2023)

This trial was conducted to evaluate growth dynamics and defoliation frequency of Italian ryegrass (Lolium multiflorum) and Paspalum urvillei in a lowland area under three levels of P and K. Using randomization tests we observed that, in a general way, fertilizer treatments were not the determinant factors of leaf appearance and elongation rates for both species. Only the leaf appearance rate of Paspalum urvillei at 100 % of recommendation level and the elongation rate for Italian ryegrass, in the same treatment, was different. Probably other factors, like drainage, are contributing to these results. I. ryegrass phyllochron ranged from …

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Cenomanian–Turonian Oceanic Anoxic Event (Oae2) Imprint On The Northwestern Part Of The Adriatic Carbonate Platform And A Coeval Intra-Platform Basin (Istria And Premuda Island, Croatia), Vlatko Brčić, Bosiljka Glumac, Mihovil Brlek, Ladislav Fuček, Martina Šparica Miko Sep 2021

Cenomanian–Turonian Oceanic Anoxic Event (Oae2) Imprint On The Northwestern Part Of The Adriatic Carbonate Platform And A Coeval Intra-Platform Basin (Istria And Premuda Island, Croatia), Vlatko Brčić, Bosiljka Glumac, Mihovil Brlek, Ladislav Fuček, Martina Šparica Miko

Geosciences: Faculty Publications

The Cenomanian–Turonian boundary (CTB) on the intra-Tethyan Adriatic Carbonate Platform (AdCP) is generally characterised by a transition between microbially laminated and/or bioclastic limestones to calcisphere-rich massive limestone with bioturbated intervals, organic-rich interbeds, firmgrounds, as well as neptunian dikes, carbonate turbidites, tempestites and slumped structures. Compilation of the results from two study sites in the northwestern part of the AdCP and from previous research (on Istria Peninsula and islands in the Adriatic Sea in Croatia) provides a more complete overview of geological events and paleoenvironmental conditions that transformed the formerly contiguous shallow-marine environments during this time period. For the first time, …

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(Re)Proposal Of Three Cambrian Subsystems And Their Geochronology, Ed Landing, Gerd Geyer, Mark D. Schmitz, Thomas Wotte, Artem Kouchinsky Sep 2021

(Re)Proposal Of Three Cambrian Subsystems And Their Geochronology, Ed Landing, Gerd Geyer, Mark D. Schmitz, Thomas Wotte, Artem Kouchinsky

Geosciences Faculty Publications and Presentations

The Cambrian is anomalous among geological systems as many reports divide it into three divisions of indeterminate rank. This use of “lower”, “middle”, and “upper” has been a convenient way to subdivide the Cambrian despite agreement it consists of four global series. Traditional divisions of the system into regional series (Lower, Middle, Upper) reflected local biotic developments not interprovincially correlatable with any precision. However, use of “lower”, “middle”, and “upper” is unsatisfactory. These adjectives lack standard definition, evoke the regional series, and are misused. Notably, there is an almost 50 year use of three Cambrian subsystems and a 1997 proposal …

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Effects Of Copper Oxide (Cuo) And Zinc Oxide (Zno) Nano And Bulk Forms To Soil Fungal Community [Research Note], Jonathan Jaime Guerrero, Teresita Dalisay, Nolissa Organo, Ireneo Pangga Sep 2021

Effects Of Copper Oxide (Cuo) And Zinc Oxide (Zno) Nano And Bulk Forms To Soil Fungal Community [Research Note], Jonathan Jaime Guerrero, Teresita Dalisay, Nolissa Organo, Ireneo Pangga

The Philippine Agricultural Scientist

The effects of copper oxide (CuO) and zinc oxide (ZnO) in bulk and nano forms on soil fungal community was determined. Lipa clay loam soil collected from the University of the Philippines Los Baños were placed in polypropylene bags and amended with 300 mg/L of CuO or ZnO in either forms. Colony-forming units (CFU) as well as average well color development (AWCD), functional richness and stress index were determined on day 1, 8 and 15 via indirect viable plate count method and community – level physiological profiling (CLPP). Fungal isolates from the same soil samples were likewise identified and tested …

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Assessing The Water Quality Of Three Bar-Built Estuaries In The Central Coast Of California, Micaelina Sarmiento Martinez Sep 2021

Assessing The Water Quality Of Three Bar-Built Estuaries In The Central Coast Of California, Micaelina Sarmiento Martinez

Master of Science in Environmental Sciences and Management Projects

Estuaries are coastal confluences with innumerable ecosystem services. With the continuous change in land use including the increasing number of people moving to live in coastal areas and on-going agricultural operations, these coastal systems are being adversely impacted. Climate change is also negatively affecting estuaries. Subsequently, this research study assessed the water quality, monthly, at three different locations of three bar-built estuaries in the Central Coast of California. Water quality was evaluated by the change in chlorophyll-a, nitrogen, phosphorus, pH, temperature, dissolved oxygen, and specific conductivity over the course of 19 months. The eutrophication potential and the role of open …

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Ocean Regime Shift Is Driving Collapse Of The North Atlantic Right Whale Population, Erin L. Meyer-Gutbrod, Charles H. Greene, Kimberley T.A. Davies, David G. Johns Aug 2021

Ocean Regime Shift Is Driving Collapse Of The North Atlantic Right Whale Population, Erin L. Meyer-Gutbrod, Charles H. Greene, Kimberley T.A. Davies, David G. Johns

Faculty Publications

Ocean warming linked to anthropogenic climate change is impacting the ecology of marine species around the world. In 2010, the Gulf of Maine and Scotian Shelf regions of the Northwest Atlantic underwent an unprecedented regime shift. Forced by climate-driven changes in the Gulf Stream, warm slope waters entered the region and created a less favorable foraging environment for the endangered North Atlantic right whale population. By mid-decade, right whales had shifted their late spring/summer foraging grounds from the Gulf of Maine and the western Scotian Shelf to the Gulf of St. Lawrence. The population also began exhibiting unusually high …

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Assessment Of Groundwater Quality In Areas Surrounding Thundulu Phosphate Mine, Phalombe District, Malawi, Philip Jailos, Peter J. Chimtali, Ephraim Vunain Aug 2021

Assessment Of Groundwater Quality In Areas Surrounding Thundulu Phosphate Mine, Phalombe District, Malawi, Philip Jailos, Peter J. Chimtali, Ephraim Vunain

Tanzania Journal of Science

Water is one of the renewable resources essential for sustaining all forms of life and quality of drinking water is very fundamental for human health. Human activities such as mining act as sources of water contamination which consequently lead to ecological, environmental and health problems. To the best of our knowledge, no study has been conducted around the Thundulu Phosphate Mine to establish the quality of drinking water. In this regard, this study was carried out to evaluate the physico-chemical water quality parameters of areas surrounding the Thundulu Phosphate Mine in Phalombe District. Groundwater samples from the villages surrounding the …

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Mollusc Shells From Neolithic Contexts In The Lake Eyasi Basin, Northern Tanzania, Musa S. Mwitondi, Albert S. Mjandwa, Pastory M. Bushozi Aug 2021

Mollusc Shells From Neolithic Contexts In The Lake Eyasi Basin, Northern Tanzania, Musa S. Mwitondi, Albert S. Mjandwa, Pastory M. Bushozi

Tanzania Journal of Science

The study of the Neolithic period in the Lake Eyasi Basin was dominated by attempts to formulate the area’s chronology, mobility, settlement patterns, subsistence, and cultural capabilities of Neolithic people as attested by domesticated animals, pottery, and lithic artefacts. Occasionally, studies on molluscs were mentioned, but rarely described in detail. Neolithic sites across the Lake Eyasi Basin have yielded remains of both terrestrial (gastropods) and freshwater mollusc shells (mussels). The abundance of mollusc shell remains in the archaeological records of the Lake Eyasi Basin have played a great role in chronological settings, mobility and community integrations, studies of settlement patterns, …

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Effect Of Temperature On Phenology In Triple-Awned Grass (Stipagrostis Plumosa), Hossein Azarnivand, H. Dastmalchi Aug 2021

Effect Of Temperature On Phenology In Triple-Awned Grass (Stipagrostis Plumosa), Hossein Azarnivand, H. Dastmalchi

IGC Proceedings (1977-2023)

Phenology of triple-awned grass in different stages of vegetative growth, flowering and seed falling was investigated. Each phenological stage was related to minimum and maximum air and soil surface temperatures. Soil surface temperature was measured two times per day during different seasons. Climate data were obtained from the nearest weather station. The study was carried out in sand dunes of band-e-rig of Kashan in the central region of Iran. This species is important in terms of wind erosion control and livestock feeding in arid areas. The results showed that air temperatures ranged from –22 oC to 41.5 oC …

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Tillering Dynamics In Mombaça Grass (Panicum Maximum, Jacq.) Under Grazing, E. M. Coelho, V. R. Herling, M. A. Gomes, R. J. Schmidt, C. G. Lima Aug 2021

Tillering Dynamics In Mombaça Grass (Panicum Maximum, Jacq.) Under Grazing, E. M. Coelho, V. R. Herling, M. A. Gomes, R. J. Schmidt, C. G. Lima

IGC Proceedings (1977-2023)

An experiment was conducted in Pirassununga, Southeastern Brazil, to observe tillering pattern of Mombaça grass (Panicum maximum Jacq.) after grazing. A complete randomized block design was used with treatments arranged in factorial (3 herbage allowances X 2 grazing periods). There was high and positive correlations between the total tiller population and the number of tillers until the third week after grazing, giving evidence of a higher tillering until the second week and a slight reduction on the third one. The Mombaça grass tillering dynamics alters along the weeks according the allowance level adopted.

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Herbage Allowance And Nitrogen Fertilization Effects On Morphological Characteristics Of Paspalum Notatum Flügge, P. Boggiano, G. E. Maraschin, Carlos Nabinger, J. Riboldi, Mónica Cadenazzi Aug 2021

Herbage Allowance And Nitrogen Fertilization Effects On Morphological Characteristics Of Paspalum Notatum Flügge, P. Boggiano, G. E. Maraschin, Carlos Nabinger, J. Riboldi, Mónica Cadenazzi

IGC Proceedings (1977-2023)

The grazing study was conducted at the Estação Experimental Agronomica – UFRGS, 30o S, on a native pasture, to evaluate the leaf area index and structural morphological traits of bahiagrass (Paspalum notatum Fl.), within the requirements of a Central Composite Rotatable experimental design, providing for equal precision, with two blocks, encompassing two factors at five levels each, namely: Herbage Allowance (HA) = 4.0; 5.5; 9.0; 12.5 and 14.0 kg green dry matter per 100 kg liveweight per day (% LW), in association with Nitrogen (N) fertilization levels of 0; 30; 100; 170 and 200 kg ha-1 as …

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Defoliation And Water Deficit: Their Influence On Pasture Growth And Water Use Of White Clover, F. H. Santiñaque Aug 2021

Defoliation And Water Deficit: Their Influence On Pasture Growth And Water Use Of White Clover, F. H. Santiñaque

IGC Proceedings (1977-2023)

With the objective of understanding the physiological basis of defoliation and water use relationships of white clover (Trifolium repens L.) pastures during water deficits, an experiment in controlled conditions was carried out. Outdoors nine liters pots were filled with a loam-clay soil with a water content at field capacity (FC), of 35%(w/w), at a bulk density of 1.1 g/cm3. Pre-germinated and inoculated clover seeds were transplanted, and the number of plants was adjusted to permit the development of full plant cover. The level of P in the soil did not limit plant establishment or growth. The …

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Seasonal Botanical Composition And Available Forage Of Natural Grasslands In The Southeastern Range Region Of Rio Grande Do Sul, Brazil, J. C. L. Reis, H. Alfaya, O. J. W. Siqueira, C. B. Farias Jr. Aug 2021

Seasonal Botanical Composition And Available Forage Of Natural Grasslands In The Southeastern Range Region Of Rio Grande Do Sul, Brazil, J. C. L. Reis, H. Alfaya, O. J. W. Siqueira, C. B. Farias Jr.

IGC Proceedings (1977-2023)

The objective of the study was to verify the influence of climatic seasons on botanical composition and on available dry matter of grasslands in the physiographic region known as Serra do Sudeste (Southeastern Range), RS, Brazil. The climate is Cfb according to Koëppen`s classification. The experiment was conducted in two natural grasslands submitted to two pre-experimental stocking rates [area 1: 0.65 AU ha-1 (normal grazing); area 2: over 2.0 AU ha-1 (overgrazing); AU: Animal Unit = 500kg live weight]. Stocking rates throughout the experimental period (June 1996–July 1997) were 0.4 and 0.65 AU ha-1, over winter …

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Effect Of Climatic Factors On The Plant Population Dynamics In Temperate Pasture Implantation, B. Martin, R. Refi, S. Montico, M. Costanzo Aug 2021

Effect Of Climatic Factors On The Plant Population Dynamics In Temperate Pasture Implantation, B. Martin, R. Refi, S. Montico, M. Costanzo

IGC Proceedings (1977-2023)

The objective of this experiment was to determine the environmental influence on seedling emergence of alfalfa and fescue in mixture. We hypothesized that the temperature and precipitation data could be used to estimate field emergence of alfalfa and fescue. A field trial was carried out at Zavalla, Argentina and consisted of sowing a tall fescue – alfalfa mixture at different seeding date (March, April and June). Relationships between the range of temperature, rainfalls and alfalfa and fescue seedling emergence were described by linear regression models. Patterns of emergence and death of alfalfa and fescue seedling were found in the different …

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Dormant Bud Development In Phalaris Aquatica L., Brendan R. Cullen, P. E. Quigley, D. F. Chapman Aug 2021

Dormant Bud Development In Phalaris Aquatica L., Brendan R. Cullen, P. E. Quigley, D. F. Chapman

IGC Proceedings (1977-2023)

The formation of dormant buds is critical to the summer survival of phalaris (Phalaris aquatica L.) in pastures. Dormant buds are formed on the base of reproductive tillers as they develop in spring. This project aimed to determine the seasonal pattern of dormant bud development and the influence of grazing management on bud dynamics. Approximately three buds per reproductive tiller were formed in the spring and early summer period. These buds responded to summer rainfall, with one third of buds becoming active following a 15-mm rainfall event in mid summer. In the following growing season, on average, 1.5 buds …

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Tillering Dynamics Of Panicum Maximum Jacq. Cv. Tanzania-1 After Grazing, Rodrigo A. Barbosa, Domicio Nascimento Jr., Valéria P. B. Euclides, A. J. Regazzi, D. M. Fonseca Aug 2021

Tillering Dynamics Of Panicum Maximum Jacq. Cv. Tanzania-1 After Grazing, Rodrigo A. Barbosa, Domicio Nascimento Jr., Valéria P. B. Euclides, A. J. Regazzi, D. M. Fonseca

IGC Proceedings (1977-2023)

Tillering dynamics and tiller dry matter weight from Tanzania grass (Panicum maximum cv. Tanzania-1) were evaluated in two post-grazing stubbles (High Post-grazing Stubble – HPS-3.6 t of DM/ha and Low Post-grazing Stubble – LPS-2.3 t of DM/ha). There was no difference between post-grazing stubbles for decapitated axillary and basal remainder and new axillary tillers. The LPS presented greater number of new basal tillers. The rate of appearance of new basal and axillary tillers decreased with time after grazing. There were differences between the treatments on tiller dry matter weight, and greater values were found in the high post-graze stubble.

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Suitable Seed Harvesting Time For Six Grass Species, Hossein Arzani, A. Fakhireh Aug 2021

Suitable Seed Harvesting Time For Six Grass Species, Hossein Arzani, A. Fakhireh

IGC Proceedings (1977-2023)

Determination of the best period of seed harvesting was considered. Six grass species were selected. The research was conducted in three stations of Alborz, Sirachal and Homand Absard. According to maturing stages, seed collection for measuring seed water content (moisture content), weight of 1000 seeds and germination percentage has been done. The result showed that there were significant differences between harvesting time on seed germination for all species in all regions. Moisture content, germination rate, weight of 1000 seeds and seed shedding were important characteristics for determination of suitable seed harvesting time.

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Effect Of Nitrogen Fertilizer On Reproductive Tiller Development In Perennial Ryegrass, I. Bahmani, E. R. Thom, C. Matthew, G. Lemaire Aug 2021

Effect Of Nitrogen Fertilizer On Reproductive Tiller Development In Perennial Ryegrass, I. Bahmani, E. R. Thom, C. Matthew, G. Lemaire

IGC Proceedings (1977-2023)

The objective of this study was to compare reproductive tiller development in two ryegrass (Lolium perenne L.) cultivars, when fertilized with nitrogen. Plots of the cultivars ‘Grasslands Ruanui’ and ‘Ellett’ ryegrass were sown in April 1996. Half of each plot received nitrogen fertilizer (30 kg N/ha) after each grazing by dairy cows from September 1996 to May 1997 and from October 1997 to April 1998. Ryegrass tiller dynamics was monitored from September 1996 to March 1998. The proportion of reproductive tillers in the total tiller population was higher, on average, over the first flowering period (October 1996 to January …

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Yield And Forage Quality In Alfalfa-Weeping Lovegrass Mixtures, H. Laborde, R. E. Brevedan, M. A. Varillas, M. N. Fioretti Aug 2021

Yield And Forage Quality In Alfalfa-Weeping Lovegrass Mixtures, H. Laborde, R. E. Brevedan, M. A. Varillas, M. N. Fioretti

IGC Proceedings (1977-2023)

Little is known about the relative performance of weeping lovegrass in mixtures with alfalfa. Our objective was to compare the productivity and forage quality of monocultures and binary mixtures of the species. Mixtures always gave higher yields than any of the monocultures and the highest was obtained in the mixture with the largest proportion of alfalfa. In the second year weeping lovegrass N concentration in the mixtures were higher than in monoculture. Weeping lovegrass did not affect the alfalfa N concentration. There was not differences in the NDF, for between these species.

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Intake And Yield Of Cynodon Nlemfuensis Alone And Associated With Leucaena Leucocephala Grazed By Sheep, J. G. Escobedo-Mex, Luis Ramírez-Avilés, Juan C. Ku-Vera Aug 2021

Intake And Yield Of Cynodon Nlemfuensis Alone And Associated With Leucaena Leucocephala Grazed By Sheep, J. G. Escobedo-Mex, Luis Ramírez-Avilés, Juan C. Ku-Vera

IGC Proceedings (1977-2023)

The objective of the present study was to determine dry matter intake (DMI) and the forage yield of green dry matter (GDM) of star grass (Cynodon nlemfuensis) alone and associated with Leucaena leucocephala cv. Perú grazed by sheep. The experimental treatments were: Systems T1) Star grass alone, and T2) Star grass + L. leucocephala. These treatments were evaluated during three seasons (i.e. Late-rainy, Dry and Rainy seasons). The availability of forage was lower (P < 0.0001) in T1, 2543 kg GDM/ha, than with T2, 3092 kg GDM/ha. Green dry matter in the rainy season was greater (P < 0.0001), with 3910 kg GDM/ha, than in the late-rainy and dry seasons, 2492 and 2052 kg GDM/ha, respectively. DMI was 5.9 and 7.6 g DM/kg of LW 0.75/hour for the T1 and T2, respectively (P < 0.0001). DMI during the rainy season was lower (P < 0.01) than that of the dry and late-rainy seasons, 6.2, 6.4 and 7.5 g DM/kg LW0.75/hour, respectively. The association C. nlemfuensis-L. leucocephala increased the availability of …

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New Insights Into The Drainage Of Inundated Ice-Wedge Polygons Using Fundamental Hydrologic Principles, Dylan R. Harp, Vitaly A. Zlotnik, Charles J. Abolt, Bob Busey3, Sofia T. Avendaño, Brent D. Newman, Adam L. Atchley, Elchin Jafarov, Cathy J. Wilson, Katrina E. Bennett Aug 2021

New Insights Into The Drainage Of Inundated Ice-Wedge Polygons Using Fundamental Hydrologic Principles, Dylan R. Harp, Vitaly A. Zlotnik, Charles J. Abolt, Bob Busey3, Sofia T. Avendaño, Brent D. Newman, Adam L. Atchley, Elchin Jafarov, Cathy J. Wilson, Katrina E. Bennett

Department of Earth and Atmospheric Sciences: Faculty Publications

The pathways and timing of drainage from the inundated centers of ice-wedge polygons in a warming climate have important implications for carbon flushing, advective heat transport, and transitions from methane to carbon dioxide dominated emissions. Here, we expand on previous research using a recently developed analytical model of drainage from a low-centered polygon. Specifically, we perform (1) a calibration to field data identifying necessary model refinements and (2) a rigorous model sensitivity analysis that expands on previously published indications of polygon drainage characteristics. This research provides intuition on inundated polygon drainage by presenting the first in-depth analysis of drainage within …

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Allelopathy Of Panicum Maximum Jacq. Cultivars On Tree And Shrub Forage Legumes: Greenhouse Estimate, A. R. P. Almeida, T. J. D. Rodrigues Aug 2021

Allelopathy Of Panicum Maximum Jacq. Cultivars On Tree And Shrub Forage Legumes: Greenhouse Estimate, A. R. P. Almeida, T. J. D. Rodrigues

IGC Proceedings (1977-2023)

The available information about allelopathic effects of the genus Panicum on tropical forage legumes is scarce and inconclusive. Based on this fact this research was carried out, under greenhouse conditions to evaluate potential allelopathic effects of aqueous extracts (0,10 and 20%) of three cultivars of Panicum maximum Jacq. cv. Mombaça, cv. Aruana and cv. Tanzânia-1 on three forage legumes, Leucaena leucocephala (Lam.) de Wit. (leucaena), Cajanus cajan (L.) Millsp. cv. Kaki (pigeon pea) and Sesbania sesban (L.) Merr. (sesbania) seeking for mixed grasses and legumes pastures. The following characteristics were evaluated: emergence porcentage, speed of germination index, root density, dry …

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Tillage Systems In The Establishment Of Pastures In Argentinian Subhumid Area, H. Pagliaricci, C. Saroff, A. Ohanian, T. Pereyra Aug 2021

Tillage Systems In The Establishment Of Pastures In Argentinian Subhumid Area, H. Pagliaricci, C. Saroff, A. Ohanian, T. Pereyra

IGC Proceedings (1977-2023)

The effect of three tillage systems on the number of plants produced and forage production of a pasture the first year of establishment was assessed in this experiment. The components of the pasture were alfalfa (Medicago sativa L.), tall fescue (Festuca arundinacea Shreb), orchard grass (Dactilys glomerata L), and prairie grass (Bromus unioloides). Treatments were three tillage systems: conventional tillage (CT), reduced tillage (RT), and direct sowing (DS). Sowing was performed with (NI) and without fertilizers (N0) in each treatment. A split-plot experimental design with two repetitions was used, with tillage being the main factor …

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