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Full-Text Articles in Physical Sciences and Mathematics
Effects Of Vesicular-Arbuscular Mycorrhiza Inoculation, Nitrogen And Phosphorus On The Growth Of Seedlings Of Sesbania Sesban, E Akeampong, T Mamo
Effects Of Vesicular-Arbuscular Mycorrhiza Inoculation, Nitrogen And Phosphorus On The Growth Of Seedlings Of Sesbania Sesban, E Akeampong, T Mamo
IGC Proceedings (1993-2023)
In the first of two pot experiments, growth of seedlings of Sesbania sesban in response to rates of P (0, 40, 120, 160 and 200 kg/ha) and of N (0 11nd 100 kg/ha) was examined. In a second trial the effect of inoculation with vesicular-arbuscular mycorrhiza (Glomus macrocarpus) and 2 levels (0 and 40 kg/hn) each of triple superphosphnte (TSP) and Egyptian rock phosphate (ERP) were studied. Response to P was linear to 80 kg/ha. Application of N improved the response of seedlings to P through enhanced P and N uptake. Application of N increased plant weight by …
Effect Of Nitrogen Application On Symbiotic Nitrogen Fixation Of White Clover Ecotypes Collected In North-Eastern Japan, K Sugawara, A Nishiwaki, Y Yashima
Effect Of Nitrogen Application On Symbiotic Nitrogen Fixation Of White Clover Ecotypes Collected In North-Eastern Japan, K Sugawara, A Nishiwaki, Y Yashima
IGC Proceedings (1993-2023)
Escaped plants of white clover which could not be identified by variety were collected and were grown in pots filled with a perlite contained nutrient solution in a growlh chamber. On 16 of the collecled plants, the change of the nitrogenase activity by treatments with or without nitrogen (20 ppm N, NaNO3) was measured by gas chromatogrnphy and the variation of peroxidase isozyme was analysed by means of slab acrylamide gel electrophoresis. The studied plants of white clover (Trifolium repens L.) were classified into 5 types by the response pattern of nitrogenase to N applied. Six bands showing peroxidase …
Varietal Differences In Brassica Fodder As Affected By Nitrogen Topdressing And Seeding Date, S H. Moon, H Hirota
Varietal Differences In Brassica Fodder As Affected By Nitrogen Topdressing And Seeding Date, S H. Moon, H Hirota
IGC Proceedings (1993-2023)
Two experiments were carried out both in spring and fall with cultivars of rape (Brassica napus spp.) and C.O. (B. campestris x B. oleracea). Both cullivars showed lillle increase in plant length in spring sowing with nitrogen topdressing, but the increments were higher in earlier topdressing (T l) and later topdressing (T2) than in control in autumn sowing, although the difference was not significant. There was no difference in the number of leaves throughout the growing stages between the N topdressing treatments in spring and autumn sowing. Leaf area was greater in Tl and T2 than in control in early …
Reserve Mobilization During Regrowth After Cutting Of Forage Species: Quantification And Physiological Mechanisms In Ryegrass And Lucerne, A Ourry, J Bigot, T Kim, J Boucaud, J Salette
Reserve Mobilization During Regrowth After Cutting Of Forage Species: Quantification And Physiological Mechanisms In Ryegrass And Lucerne, A Ourry, J Bigot, T Kim, J Boucaud, J Salette
IGC Proceedings (1993-2023)
Time course of remobilisation of reserves was studied during the regrowth of Loli11m perem1e and Medicago sativa by 15N labelling, carbohydrate analyses and by measuring time course of several enzymes activities. When photosynthesis decreased during early regrowth, and consequently reduced availability of carbon skeletons within the plant, both nitrogen (N) uptake (lolium perene) and N2 fixatlon (Medicago saliva) decreased. Nilrogenase, as well as nitrate reductase activities, decreased. Reduction of external N assimilation was compensated for by intensive mobilization of endogenous N in roots of lucerne and in stubble of ryegrass. In the same manner, some of …
Impact Of Intermittent Clipping On Productivity, Forage Quality And Legume Persistence Of Reclaimed Mine Soils, M Collins, H B. Rice, R Turley, W O. Thom
Impact Of Intermittent Clipping On Productivity, Forage Quality And Legume Persistence Of Reclaimed Mine Soils, M Collins, H B. Rice, R Turley, W O. Thom
IGC Proceedings (1993-2023)
The materials used as plant growth media during surface mine· reclamation are frequently low in available N, P and K and are droughtprone. Legumes are included in reclamation seeding mixtures . because of their symbiotic N2-fixation ability but competition may prevent establishment or reduce persistence. A field study was conducted to test the hypothesis that intermittent clipping of these sites would reduce grass competition and thereby maintain legume stands. In 1990 and· 1991, 4 clipping treatments were imposed, providing intervals of 2, 4; and 6 weeks between harvests. Clipping at the 2- or 4-week intervals gave equal yields that were …
Effects Of Nitrogen And Potassium Fertilizers On Forage Yield And Quality Of Dwarf Napiergrass, F H. Hsu, K Y. Hong
Effects Of Nitrogen And Potassium Fertilizers On Forage Yield And Quality Of Dwarf Napiergrass, F H. Hsu, K Y. Hong
IGC Proceedings (1993-2023)
The experiment was conducted to determine effects of nitrogen and potassium fertilisers on forage yield and quality of dwarf napiergrass (Pennisteum purpuretum). Four levels of N (460, 690, 920 and 1150 kg/ha), and 4 levels of K2O (150, 300, 450 and 600 kg/ha), and 1 level of P2O5 (144 kg/ha), were applied. Forage yield, leaf area per tiller, leaf elongation rate and forage quality of dwarf napiergrass were increased when N level applied was increased. Leaf growth, tiller number and forage yield were not affected by K applied. However, Ca and Mg contents in plant were reduced and …
Application Of Dairy Manure On Alfalfa, Stephen J. Herbert, Jayarm Daliparthy, P L.M Veneman
Application Of Dairy Manure On Alfalfa, Stephen J. Herbert, Jayarm Daliparthy, P L.M Veneman
IGC Proceedings (1993-2023)
Applying dairy manure to alfalfa (Medicago sativa L.) as ,in alternative 10 excess application to· corn (Zea mays L.) may reduce nitrate pollution of groundwater. Field experiments were conducted at 2 sites in Massachusetts, USA, lo study the impact or dairy manure application to alfalfa on forage yield, weed infestation· and nitrate movement. Treatments were an unfertilized (no N) check.· plot, low and high manure (112 and 336 kg N/ha/year equivalerit), and low and high N fertiliser (112 and 336 kg N/ha/year from NH4NO3),'. Liquid dairy manure was applied 10 • alfalfa immediately· after 1st· cutting during spring …
Nitrogen And Phosphorus Nutrition Of Digitaria Eriantha: Is It Limited By Absorption Capacity Or Rate Of Supply?, M C. Scholes, R J. Scholes, J Retief
Nitrogen And Phosphorus Nutrition Of Digitaria Eriantha: Is It Limited By Absorption Capacity Or Rate Of Supply?, M C. Scholes, R J. Scholes, J Retief
IGC Proceedings (1993-2023)
Digitaria eriantha was grown from seed collected from low and high nutrient habitats. The plants were grown with either a high or low nutrient supply for 12 weeks. Rates of nitrogen and phosphorus absorption were measured on excised roots using colorimetric assays. The grasses from the low nutrient areas achieved the same maximum uptake rates regardless of the level of N supplied, This was not so for the grasses from the high nutrient site which increased their uptake rates with increased N supply. Plants from the low nutrient site showed markedly increased P absorption when supplied with high levels of …
The Value Of Adapted, Annual Ryegrasses For Subtropical Dairy Production, K F. Lowe, T M. Bowdler, G K. Reason, R J. Moss
The Value Of Adapted, Annual Ryegrasses For Subtropical Dairy Production, K F. Lowe, T M. Bowdler, G K. Reason, R J. Moss
IGC Proceedings (1993-2023)
Cutting and grazing experiments were conducted in a subtropical environment to determine whether a relationship existed between differences measured in ryegrass cultivars from cutting experiments and milk production differences under grazing. Differences in dry mauer (OM) production under cutting between the standard annual ryegrass for the subtropics (Grasslands Tama) and a cultivar selected for superior performance under subtropical conditions (Midmar) averaged 31 %, differences in feed on offer under grazing averaged 21 %, while milk production differences averaged 10% in a 2-year study. The results indicate that increases in OM yield measured in cutting experiments will be consistent wlth differences …
Effects Of Herbicides And Fertilizers On Ragwort (Senecio Jacobaea L.) In Hill Country Pastures, A Rahman, K S. Nicholson, D A. Wardle
Effects Of Herbicides And Fertilizers On Ragwort (Senecio Jacobaea L.) In Hill Country Pastures, A Rahman, K S. Nicholson, D A. Wardle
IGC Proceedings (1993-2023)
A 3-year study was conducted lo determine the influence of 2 herbicides (2,4-D and glyphosate) and 3 fertilisers (containing N, P or K), in conjunctiun with pasture renovation, on ragwort (Senecio jacobaea L.) populations and pasture productivity in a perennial ryegrass-white clover hill country pasture. Glyphosate-treated plots often contained higher ragwort numbers than 2,4-D treated plots, probably because the glyphosate treatment caused greater discontinuity of pasture. Both N and P fertilisers had a consistently strong beneficial effect on pasture, which resulted in substantial inhibition of ragwort populations. During the end of each of the first 2 years of the …
Nitrogen Nutrition Of Brant (Branta Bernicla L.) Grazing On Saltmarsh And Pasture Species, G Q.A Anderson, M Andrews, S M. Percival, J S. Kirby
Nitrogen Nutrition Of Brant (Branta Bernicla L.) Grazing On Saltmarsh And Pasture Species, G Q.A Anderson, M Andrews, S M. Percival, J S. Kirby
IGC Proceedings (1993-2023)
Captive brant Branta bernicla were fed a range of food plants to determine their ability to digest nitrogen and specifically soluble protein. Soluble protein levels in droppings were only a small fraction of those in plants, indicating substantial uptake or conversion. For white clover Trifolium repens L., uric acid content indicated that at least 50% of excreted nitrogen had been metabolised, strongly suggesting that a substantial fraction of soluble protein is utilised by the geese. Carbon/nitrogen ratios increased from plants to droppings while carbon/hydrogen ratios remained nearly constant indicating greater uptake of nitrogen relative to carbon. T. repens was found …
Utilization Of Regrowth For Forage In Seed Stands Of Meadow Fescue (Festuca Pratensis Huds.), Lars T. Havstad
Utilization Of Regrowth For Forage In Seed Stands Of Meadow Fescue (Festuca Pratensis Huds.), Lars T. Havstad
IGC Proceedings (1993-2023)
Intensive utilization of autumn regrowth for forage production was compared to other autumn treatments in nine seed production fields of meadow fescue (Festuca pratensis) during 1993-96. Uncut plots without a N application in autumn always had the lowest number of reproductive tillers and the lowest subsequent year seed yields. Intensive utilization of regrowth, by application of 80 kg N ha-1 immediately after seed harvest and forage harvests in September or October, did not have any negative impact on the following yearsí seed yields. Delaying forage harvest from 10 September to 10 October increased forage yields, but lowered the …
Towards A Model For Nitrogen Application To Seed Crops Of Timothy (Phleum Pratense), T S. Aamlid
Towards A Model For Nitrogen Application To Seed Crops Of Timothy (Phleum Pratense), T S. Aamlid
IGC Proceedings (1993-2023)
In seed production experiments with timothy (Phleum pratense L.) split application of 25 kg N ha-1 as early as possible in spring (mean date 17 April) plus 50 kg ha-1 at the start of tiller elongation (mean date 19 May) increased seed yields compared to only one application of 75 or 100 kg N ha-1 in mid-May. On plots not receiving nitrogen until mid-May, the seed yield increase resulting from an additional application of 25 kg N ha-1 at heading (mean date 19 June) could be related to the ratio between measured and critical per cent nitrogen in plant …
Bermudagrass Pastures Under Long-Term Stocking Rates And Fertility Regimes, F M. Rouquette Jr, G R. Smith, V A. Haby
Bermudagrass Pastures Under Long-Term Stocking Rates And Fertility Regimes, F M. Rouquette Jr, G R. Smith, V A. Haby
IGC Proceedings (1993-2023)
After 16 years of grazing ‘Coastal’ and common bermudagrass [Cynodon dactylon (L.) Pers.] pastures each at 3 levels of forage mass, N vs non-N fertilizer was superimposed to assess stand maintenance of bermudagrass and cow-calf performance. After 7 additional years of fertility treatments, N plus overseeded ryegrass (Lolium multiflorum Lam.) provided for 202 days grazing; whereas, K plus overseeded clovers (Trifolium incarnatum L.) and (T. vesiculosum Savi.) provided adequate forage for 179 days grazing. Coastal supported higher stocking rates (2.3 to 7.9 680-kg animal units(AU)/ha) than common bermudagrass (2.0 to 5.3 AU/ha). Suckling calf daily gains …
White Clover Versus Nitrogen Fertilizer 2. Sheep Production, J.P J. Erens, K B. Miller, R J. Lucas, J.G. H. White, H S. Easton
White Clover Versus Nitrogen Fertilizer 2. Sheep Production, J.P J. Erens, K B. Miller, R J. Lucas, J.G. H. White, H S. Easton
IGC Proceedings (1993-2023)
Animal production on pasture systems provided with either fertiliser or biological nitrogen was compared. A grazing experiment was sown at AgResearch Gore (46°07’ S; 168°54’ E) in October, 1989. Four ryegrass/white clover paddocks were compared to four ryegrass paddocks, with the latter receiving 270 kg nitrogen/ha/year. Each paddock of 0.5 ha was subdivided for rotational grazing at 20 ewes/ ha. In comparison to the ryegrass pastures, mixed pastures produced 22% more herbage and were subsequently 22% higher stocked, lamb liveweight gains were 12% higher during lactation and 42% higher after weaning resulting in earlier sale at higher carcass weights. Ewe …
Effect Of Nitrogen On The Reserve Nutrients Of Rhizomes And Their Relation To Shoot Regrowth In Miscanthus Floridulus, Y C. Wang, M L. Lee
Effect Of Nitrogen On The Reserve Nutrients Of Rhizomes And Their Relation To Shoot Regrowth In Miscanthus Floridulus, Y C. Wang, M L. Lee
IGC Proceedings (1993-2023)
A 3-week-treatment of nitrogen dressings and of shoot cuttings were conducted on Miscanthus floridulus before the harvest. The nitrogen dressing increased the fresh weight and dry matter of the plants, but did not increase the plant height and shoot number. The reserved nutrients, especially the sugars and starch in the rhizomes were decreased by the cut treatments. Crude protein in the rhizomes was increased with the nitrogen amounts applied, though the carbohydrates were decreased. The decrease in reserved nutrients caused the growth inhibition of new shoots, and the more the reserved nutrients decreased the more severely was the growth inhibited. …
Monitoring The Movement Of N And S Through The Soil Plant Animal System Under Degraded And Perennial Pastures, Chen Wen, R.D B. Lefroy, G J. Blair, J M. Scott
Monitoring The Movement Of N And S Through The Soil Plant Animal System Under Degraded And Perennial Pastures, Chen Wen, R.D B. Lefroy, G J. Blair, J M. Scott
IGC Proceedings (1993-2023)
An experiment was carried at Armidale, NSW, Australia, to test the hypothesis that pastures dominated by the perennial grass phalaris (Phalaris aquatica) together with white clover (Trifolium repens) can optimize nutrient cycling and minimize nutrient leakage in comparison with one where the perennial grass has been lost through prior overgrazing (‘degraded’). The concentrations of mineral nitrogen present as ammonium and nitrate indicated limited opportunities for N leaching under either perennial or ‘degraded’ pastures in this environment. The high S content in the 40-60 cm soil layer indicates some movement of S under both ‘degraded’ and perennial …
Compatibility Of Stylosanthes Hamata And Stylosanthes Capitata In Mixed Pastures In The Subhumid Zone Of Nigeria, G Tarawali, M Peters
Compatibility Of Stylosanthes Hamata And Stylosanthes Capitata In Mixed Pastures In The Subhumid Zone Of Nigeria, G Tarawali, M Peters
IGC Proceedings (1993-2023)
The forage productivity of sole plots of Stylosanthes capitata and Stylosanthes hamata in comparison with various proportional mixtures of the two legumes and their effect on soil properties and subsequent maize yield were studied in subhumid Nigeria. Dry matter (DM) yields in the mixtures were higher than in the sole stands, with the mixtures of S. hamata and S. capitata reaching 11959 to 14822 kg/ha over a three year period. Total nitrogen and/or organic carbon concentrations in the soil following the three years of legume were higher in the mixtures than in the sole stands, and this resulted in higher …
Mineral Contents Of White Clover Grass And Nitrogen Fertilized Grass Pastures For Lambs, R Sormunen-Cristian, P Nykänen-Kurki, J Peltola
Mineral Contents Of White Clover Grass And Nitrogen Fertilized Grass Pastures For Lambs, R Sormunen-Cristian, P Nykänen-Kurki, J Peltola
IGC Proceedings (1993-2023)
The mineral contents (Ca, P, Mg, K, Na, Fe, Cu, Zn, and Mn) of white clover grass without nitrogen and grass-only pastures with annual nitrogen rates of 0, 120 and 250 kg ha-1 were studied in 1994 and 1995. The pastures were grazed twice per season by growing lambs. The white clover contents averaged 25% and 42%, respectively. The Ca and Mg contents and the Ca/P ratio were higher, and the K/(Ca+Mg) equivalent ratio lower in white clover grass than in grass-only swards. The P content of white clover grass was similar to that of grass, and the K content …
Effect Of N And P Fertilizers On Nutritive Value Of Dwarf Elephantgrass (Pennisetum Purpureum) Cv N-75 Mott, J R. Faria, B Gonzalez, J Faria-Marmoll, D E. Morillo
Effect Of N And P Fertilizers On Nutritive Value Of Dwarf Elephantgrass (Pennisetum Purpureum) Cv N-75 Mott, J R. Faria, B Gonzalez, J Faria-Marmoll, D E. Morillo
IGC Proceedings (1993-2023)
Crude protein (CP), Ca and P concentrations and in vitro dry matter digestibility (IVDMD) of irrigated dwarf elephantgrass (Pennisetum purpureum cv. N-75 Mott) as affected by the factorial combination of N (0, 150, 300 and 450 kg N/ha/year) and P (0, 50 and 100 kg P205/ha/year) fertilization was evaluated in a tropical dry forest in Zulia State, western region of Venezuela. A randomized complete block design with three replications was used. Soil was a low-fertility sandy-loam Udic Paleustalf (pH 6.1). Nitrogen fertilization did not influence (P>0.05) any of the variables. Mean CP, IVDMD, Ca and P were: 8.13, …
An Integrated Soil Testing-Modeling Approach To Improve Fertilizer Recommendations For Grassland, L Brown, D Scholefield, E C. Jewkes, N Preedy
An Integrated Soil Testing-Modeling Approach To Improve Fertilizer Recommendations For Grassland, L Brown, D Scholefield, E C. Jewkes, N Preedy
IGC Proceedings (1993-2023)
New management strategies are required in order to reduce the appreciable emissions of N from intensively managed grassland. Previous work has shown that if fertiliser is applied at rates that take account of the mineral N found in soil at the time of each application, N use efficiency can be improved. A novel approach is described which integrates soil testing and modelling to produce N fertiliser recommendations on a monthly basis. An existing annual model of the N cycle in grassland has been modified to produce monthly predictions of mineral N in the soil. The model is being validated by …
The Effect Of Fertiliser History On Nutrient Accumulation And Plant-Available Nutrient Supply In Legume-Based Pasture Soils, J L. Moir, M J. Hedley, A D. Mackay, R W. Tillman
The Effect Of Fertiliser History On Nutrient Accumulation And Plant-Available Nutrient Supply In Legume-Based Pasture Soils, J L. Moir, M J. Hedley, A D. Mackay, R W. Tillman
IGC Proceedings (1993-2023)
Animal production in New Zealand is dependent on pastoral legumes to build soil nitrogen fertility, which otherwise limits the growth of the major sward component, grass. Traditionally, in order to sustain legume vigour, single superphosphate has been applied to elevate soil phosphorus and sulphur levels. Rarely have either the agronomic or nutrient efficiencies of these systems been assessed. Fourteen hill country pasture sites in three broad rainfall regimes were chosen to assess the effect of contrasting fertiliser histories on soil fertility, in particular nitrogen availability. At each site soil fertility indices and pasture production for the 1993/94 growing season were …
Growth And Physiology Respond Differently To Elevated Co2 In Nad-Me And Nadp-Me C4 Grasses, D R. Lecain, J A. Morgan
Growth And Physiology Respond Differently To Elevated Co2 In Nad-Me And Nadp-Me C4 Grasses, D R. Lecain, J A. Morgan
IGC Proceedings (1993-2023)
Plants with C4 photosynthesis have one of three decarboxylation enzymes in their bundle sheath cells. Reports suggest that bundle sheath leakiness to CO2 is highest in the NAD-ME group, lowest in the NADP-ME group and intermediate in the PCK group. We investigated the hypothesis that growth and photosynthesis of three NADME grasses would respond more to elevated CO2 than three NADPME grasses. Contrary to our hypothesis, growth of NADP-ME grasses was greater under elevated CO2, while none of the NADME grasses had a significant response. Increased leaf non-structural carbohydrates were associated with greater growth responses of NADP-ME grasses, while none …
Nitrogen And Co2 Effects On Remobilization Of Root And Crown Reserves For Regrowth Following Defoliation, R H. Skinner, J A. Morgan, J D. Hanson
Nitrogen And Co2 Effects On Remobilization Of Root And Crown Reserves For Regrowth Following Defoliation, R H. Skinner, J A. Morgan, J D. Hanson
IGC Proceedings (1993-2023)
The effect of carbohydrate and nitrogen reserve remobilization during the first 4 d following defoliation on subsequent regrowth was studied under different soil nitrogen and atmospheric CO2 conditions. On a structural dry matter basis, elevated CO2 increased carbohydrate concentration without affecting total nitrogen in roots and crowns. High soil nitrogen had the opposite effect, increasing nitrogen concentration with no effect on nonstructural carbohydrates. Regrowth was significantly correlated with total nitrogen concentration at the time of defoliation. Carbohydrate concentration was not related to subsequent regrowth, nor was there a consistent correlation between carbohydrate or nitrogen remobilization and regrowth. No nitrogen remobilization …
Nutritive Value Of Guineagrass Cultivars In The Winter As Influenced By Nitrogen Fertilization, N.F G. Rethman, W.A J. Steenekamp
Nutritive Value Of Guineagrass Cultivars In The Winter As Influenced By Nitrogen Fertilization, N.F G. Rethman, W.A J. Steenekamp
IGC Proceedings (1993-2023)
The monitoring of yield, structure and nutritive value of four Panicum maximum (Guineagrass) cultivars, utilized as standing hay in the winter, yielded valuable data on the relative importance of nitrogen fertilization and cultivar. While nitrogen had a strong influence on yield and crude protein content it was the differences between cultivars, with respect to soil adaptation and structure, which played a dominant role. It is recommended that future research place particular emphasis on the adaptation of cultivars and genotype differences in structure.
Nitrogen In Stubble As A Limiting Factor Of Regrowth And Yield Of Orchardgrass After Cutting, T Matsunaka, T Ishii, M Jin
Nitrogen In Stubble As A Limiting Factor Of Regrowth And Yield Of Orchardgrass After Cutting, T Matsunaka, T Ishii, M Jin
IGC Proceedings (1993-2023)
Two field trials were carried out to reexamine the role of total nonstructural carbohydrates (TNC) and nitrogen (N) of the stubble in regrowth of orchardgrass (Dactylis Glomerata L.) during 10 days after cutting and the yield of next cutting. The regrowth and the yield were independent of TNC content in the stubble. They increased with N content in the stubble derived from the different rate of previous N application. When the TNC content in the stubble at the time of cutting was more than about 18% (dry matter basis), the regrowth even in a darkroom was not affected by …
An Overview Of The Physiology And Biochemistry Of N Reserves Mobilization In Forage Species, F Le Dily, A Ourry, J Boucaud
An Overview Of The Physiology And Biochemistry Of N Reserves Mobilization In Forage Species, F Le Dily, A Ourry, J Boucaud
IGC Proceedings (1993-2023)
Recent works focusing on the physiological and biochemical events associated to perennial forages sustainability (re-growth after defoliation, winter survival), provided evidence that vegetative storage proteins (VSPs, ca proteins stored in remaining organs and specifically mobilized) were key organic compounds for shoot regrowth. Attempts to elucidate environmental conditions involved in VSPs deposit ability of different species are under progress today. In contrast, mechanisms of spring- or cut-induced proteolysis are investigated at a lesser extend. This contribution is an opportunity to summarize our knowledge of N-reserves mobilization and to set the question of VSPs breakdown regulation.
Intraspecific Competition In Lucerne And Relationships With Reserve Availability, Jean Christophe Avice, Alain Ourry, Gilles Lemaire, Jeffrey J. Volenec, Jean Boucaud
Intraspecific Competition In Lucerne And Relationships With Reserve Availability, Jean Christophe Avice, Alain Ourry, Gilles Lemaire, Jeffrey J. Volenec, Jean Boucaud
IGC Proceedings (1993-2023)
Below-ground reserves are thought to provide an indication of a forage potential for shoot regrowth after defoliation. The aim of this work was to re-evaluate the causal relationships existing between organic reserves (non-structural carbohydrates and N reserves) and shoot regrowth of alfalfa. The variations brought about by cultivar differences (cv Lodi or Europe), length of the previous regrowth period (30 or 45 d), or by intraspecific competition for light within a dense canopy, were studied. Field grown plants were harvested at weekly intervals, and separated as dominant, intermediate and suppressed plants. Shoot regrowth yield was determined and taproot were analyzed …
Effects Of Nitrogen On The Growth Of Hyparrhenia Diplandra, J Nkandza
Effects Of Nitrogen On The Growth Of Hyparrhenia Diplandra, J Nkandza
IGC Proceedings (1993-2023)
The nitrogen effects on Hyparrhenia diplandra were studied. Plants were grown on nutrient solutions of variable concentrations in nitrogen. The supplied nitrogen increased tillering, leaf production, lamina area, total dry matter accumulation and total nitrogen accumulation in lamina. A detailed examination showed that the effect on tillering was the main cause of the differences observed in dry weights between different treatments. The nitrogen supply elongated significantly the lamina and nitrogen deficiency increased its thickness; but this was not enough to compensate the loss of weight in lower nitrogen treatment. The lamina area as well as nitrogen accumulation in the lamina …
Nitrogen Use Efficiency Of Timothy Populations, G Belanger, C Murray, R Michaud, F Gastal, J E. Richards
Nitrogen Use Efficiency Of Timothy Populations, G Belanger, C Murray, R Michaud, F Gastal, J E. Richards
IGC Proceedings (1993-2023)
The objective of this study was to determine the variability in N use efficiency among field-grown timothy (Phelum pratense L.) populations. Shoot biomass and N uptake were measured at the end of the spring growth cycle on six timothy populations fertilized with three N rates at two sites in Eastern Canada. The variability in shoot biomass among populations was similar under limiting and nonlimiting N conditions. The ranking of the populations, however, differed under limiting and non-limiting N conditions, and also between the two sites under limiting N conditions. The differences in shoot biomass among populations under highly N …