Distribution Des Assimilats Et Fixation D’Azote Chez Le Trefle Blanc: Influence De La Ramification Du Stolon, C Robin, V Guerin, A Guckert
IGC Proceedings (1977-2023)
Les apex de stolon representent des puits majeurs pour le carbone chez le trefle blanc (Robin et al., 1987). Ce travail vise a definir !'impact d'une ramification sur la repartition des photosynthetats. Ce puits supplementaire est susceptible d'induire notamment des relations de competition vis-a-vis des autres apex et des nodosites.
Growth And Gas Exchange Of Rhizoma Peanut (Arachis Glabrata Benth.) Subjected To Water Deficit,
2025
University of Wisconsin
Growth And Gas Exchange Of Rhizoma Peanut (Arachis Glabrata Benth.) Subjected To Water Deficit, K A. Albrecht, J M. Bennett, G M. Prine
IGC Proceedings (1977-2023)
Rhizoma peanut (Arachis glabrata Beuth.) is a long lived perennial forage legume adapted to well drained soils of Florida and the humid tropics and subtropics that are prone to both long and short term moisture deficits. The nutritive value of rhizoma peanut is similar to that of alfalfa, thus it is an excellent supplement to tropical grass pastures. Prine (1983) reported that yields of 11 t/ha are regularly obtained in northern Florida and that yield potentials could be greater in areas with longer growing seaso��and well distributed rainfall. The influence of dryught on yield and physiological responses of rhizoma …
The Effect Of Nitrogen Deficiency On Carbon Partitioning In A Tall Fescue Sward,
2025
Agriculture Canada
The Effect Of Nitrogen Deficiency On Carbon Partitioning In A Tall Fescue Sward, G Belanger, F Gastal, F R. Warembourg
IGC Proceedings (1977-2023)
Intercepted photosynthetically active radiation (PAR), lightuse efficiency and assimilate partitioning are three major determinants of crop growth (Charles-Edwards, 1982). Gastal and Lemaire (1988) reported that the amount of intercepted PAR partly explained the differences in aerial DM yield obtained with contrasting N regimes applied to a tall fescue sward. They also indicated that light-use efficiency and assimilate partitioning were involved in this N effect on DM yield but they could not differentiate between these two growth determinants. Very few field studies of the effect of a N deficiency on assimilate partitioning in forage grasses have been reported. Most studies conducted …
Etude Des Deux De La Nutrition Azotee Du Trefle Blanc (Trifolium Repens L.): Activite De La Nitrogenase Et De La Nitrate Reductase, D Schontz, C Robin, A Guckert
IGC Proceedings (1977-2023)
L'importance des deux voies de la nutrition azotee (assimilation de l'azote combine et moleculaire) du trefle blanc n'a ete etudiee qu'en terme de bilans 15N (Haystead et Lowe, 1977). L'objet de cette etude est de suivre la cinetique des activites de la nitrate reductase et de la nitrogenase au cours du cycle de developpement en presence de differentes concentrations en nitrates.
Effets Di Nitrate Sur La Croissance Et La Fixation D’Azote Chez Le Trefle Blanc (Trifolium Repens L.): Importance De La Souche De Rhizobium, D Schontz, C Robin, D Laurentie, A Guckert
IGC Proceedings (1977-2023)
Des apports d'azote combine sur des associations gramineestrefle blanc provoquent souvent un desequilibre favorable a la graminee. Cet effet peut etre attribue a une moindre competitivite de la legumineuse pour prelever l'azote combine (difference d'exploration du sol par le systeme racinaire) mais aussi a une moindre action de l'azote sur la croissance, du fait de !'inhibition de la fixation. L'objet de cette etude est de tester !'influence de la souche de Rhizobium sur la sensibilite de la fixation d'azote et sur !es consequences de cette sensibilite sur la croissance du trefle en presence de differents niveaux de nitrates.
Leaf Growth In Lolium Perenne L.,
2025
Universitat Bonn
Leaf Growth In Lolium Perenne L., H Schnyder, S Seo, W Kuhbauch
IGC Proceedings (1977-2023)
Knowledge about the spatial distribution of growth rates within the growth zone of leaves is essential for the study of metabolism associated with the growth process (Silk 1984). Such data have been described for Festuca arundinacea Schreb. during the phase of rapid blade elongation (Schnyder and Nelson 1987, 1988) and Zea mays L. during one developmental stage (Hsiao et al. 1985). No developmental studies appear to have been made. This paper describes the spatial distribution of growth rates within the elongation zone of L. perenne leaves from shortly after tip emergence to shortly before cessation of leaf growth. Special …
Analysis Of The Aerial Part And Roots Of The Lucerne Crop To Improve The Breeding Method,
2025
Instituto Sperimentale per le Colture Foraggere
Analysis Of The Aerial Part And Roots Of The Lucerne Crop To Improve The Breeding Method, P Rotili, L Zannone, G Gnocchi, S Proietti, C Scotti
IGC Proceedings (1977-2023)
In our research work we consider the lucerne crop as a « system», that means a set of elements with their reciprocal relationships (Rotili 1988). The elements of such a system are the plants ; the whole of their relationships is called the « structure » of the system ; it is expressed by the effects caused by the reciprocal interference among the plants on their morphology and physiology. Both these constituents of the system (the plants and the structure) have to be considered by the breeder to improve the lucerne crop. From some hundred experiments established with material genetically …
Relationship Of Leaf Export Of Carbohydrate To Rhizomatous Growth In Panicum Amarum L.,
2025
USDA, Agricultural Research Service
Relationship Of Leaf Export Of Carbohydrate To Rhizomatous Growth In Panicum Amarum L., D S. Fisher, J C. Burns, D H. Timothy, K R. Pond
IGC Proceedings (1977-2023)
Rhizomatous growth is desirable in pastures, yet many species used for grazing have exceedingly short rhizomes. In damaged pastures, vigorous rhizomes can provide for recovery of areas in which the stand has been lost. In breeding pasture grasses, selecting for high yields in a favorable environment may result in altered partitioning of carbohydrate between shoots and roots to favor above ground growth. In the Panicum genus, this can occur even in spaced plantings in which plants may exceed 2 m in height. The following experiment utilized a high rhizome (HR), an intermediate rhizome (IR), and a low rhizome (LR) accession …
Morphological And Physiological Growth Aspects Of Three Tropical Grasses,
2025
Universidade Federal de Vicosa
Morphological And Physiological Growth Aspects Of Three Tropical Grasses, J A. Gomide
IGC Proceedings (1977-2023)
Forage plants differ considerably regarding their ability to recover from grazing. Forage regrowth is determined by shoot apex survival (Sheard and Winch, 1966); leaf area (Ward and Blaser, 1961) ; non-structural carbohydrate content (Ward and Blaser, 1961 ; Brown and Blaser, 1965) and tillering potential (Paulsen and Smith, 1969). Little is known about these concepts regarding tropical grasses.
The Morphological Relation In The Panicle Of Panicum Maximum Jacq. Consequences On The Pollination And The Fertility,
2025
ORSTOM
The Morphological Relation In The Panicle Of Panicum Maximum Jacq. Consequences On The Pollination And The Fertility, M Noirot
IGC Proceedings (1977-2023)
In Panicum maximum, the fertility is often low : 9 to 40 % (Warmke, 1951; Javier, 1970). At the Agricultural station of Man (Ivory Coast) - a limit region for natural dispersion of guinea grass -, the same amplitude has been noted. But our observations showed a negative correlation between fertility and panicle length. The study of the spikelet distribution into the sheathed panicle and its factors of variability bring an answer to explain this phenomenon.
Phytochrome Mediated Effects On White Clover Morphogenesis,
2025
INRA
Phytochrome Mediated Effects On White Clover Morphogenesis, C Varlet-Grancher, B Moulia, R Jacques
IGC Proceedings (1977-2023)
The balance of a white clover-grass mixture mostly depends on the morphogenesis of white clover under conditions of competition for light (Beinhart, 1963 ; Gastal et al., 1986). Within the recent years, emphasis has been placed on the role of phytochrome as a shade sensor and as a controlling system for the morphogenesis of light-grown higher plants (Morgan and Smith, 1979). To our knowledge there is only one report on white clover photomorphogenesis available in the literature. This work (Solangarrachchi and Harper, 1987) deals with the effect of chlorophyllian shade on morphogenesis and the effects obtained are sometimes contradictory within …
White Clover Root Systems And Their Influence On The Survival Of Perennial Pastures In South Africa,
2025
Grassland Research Centre
White Clover Root Systems And Their Influence On The Survival Of Perennial Pastures In South Africa, A Smith, D.C W. Goodenough, A.R J. Morrison, Marie F. Smith
IGC Proceedings (1977-2023)
The eastern part of the Republic of South Africa receives a relatively high rainfall, which results in it having a high agricultural potential. The quality of natural and cultivated pastures can be vastly improved by the introduction of a legume component. In the areas where pastures are likely to develop, the soils are acid and highly leached. White clover is not normally tolerant of low P, low Ca and high Al soil contents, and due to its normally shallow rooting habit it consequently suffers easily from drought conditions, and therefore has a much reduced productive period of approximately 30 months …
Effect Of Interspecific Competition On The Development And Early Growth Of Grass Species,
2025
University of Peradeniya
Effect Of Interspecific Competition On The Development And Early Growth Of Grass Species, U R. Sangakkara, E Roberts
IGC Proceedings (1977-2023)
In a sown pasture, each individual plant tries to gain access to growth resources for its establisment and development. The more competitive species, which generally exhibits more extensive seedling growth obtains a greater share of resources, thus modifying the environment within the plant community (Black, 1966). This develops competitive relationships. As competition operates essentially at the individual plant level (Rhodes, 1970), experiments need to study the effect of neighbouring species on the growth and development of a single plant (Mead, 1979). Studies on competition between ryegrass (Lolium perenne), prairiegrass (Bromus catharticus) and cocksfoot (Dactylis glomerata …
Azote Et Equilibre De L’Association Ray-Grass Anglias-Trefle Blanc,
2025
INRA
Azote Et Equilibre De L’Association Ray-Grass Anglias-Trefle Blanc, J C. Simon
IGC Proceedings (1977-2023)
Bon nombre d'eleveurs s'interrogent sur l'interet des apports d'azote sur les associations ray-grass anglais - trefle blanc, en particulier sur la premiere pousse de printemps. Ces apports conduisent generalement a un desequilibre de !'association en faveur du ray-grass et compromettent de ce fait la perennite du melange. Apres avoir rappele brievement par quelques resultats experimentaux les principales incidences de l'azote sur le niveau de production et sur la composition de la culture mixte, nous analyserons les effets de l'azote sur l'equilibre de !'association a la lumiere des donnees recentes sur la morphogenese des deux plantes.
The Effects Of Coconut Palms On Pasture Understory,
2025
University of Reading
The Effects Of Coconut Palms On Pasture Understory, R W. Snaydon, D.N S. Fernando, R Sangakkara
IGC Proceedings (1977-2023)
Pastures are extensively grown under coconut palms, and mainly grazed by cattle (Plucknett, 1979). The main advantages of this form of mixed cropping are : (a) diversification of products, (b) additional income, (c) feed for draft animals, (d) weed control, and (e) more rapid nutrient cycling. Surprisingly little information is available on the effects of pastures and coconut palms on each other (Plucknett, 1979) ; even less is known about the mechanisms of competition between them. This study was designed to study the effects of coconut palms on pasture. A trenching technique was used to investigate the effects of below-ground …
Compatibility Of Birdsfoot Trefoil With Tall Fescue Selected For High And Low Leaf Area Expansion Rate,
2025
USDA, Agricultural Research Service
Compatibility Of Birdsfoot Trefoil With Tall Fescue Selected For High And Low Leaf Area Expansion Rate, C J. Nelson, K M. Hasson, D A. Sleper, J R. Forwood
IGC Proceedings (1977-2023)
Tall fescue (Festuca arundinacea Schreb.) populations were selected for slow and rapid leaf area expansion rate (Nelson and Sleper, 1983). Daily leaf elongation rate (LER) in the field was increased by 0.30 mm and decreased by 0.53 mm per generation (Nelson et al., 1985), but single-leaf photosynthesis was not affected. Populations selected for high LER had longer and wider leaf blades (Nelson and Sleper, 1983), and lower tiller density, higher weight per tiller, and higher forage yield in vegetative swards (Nelson et al., 1985) than those selected for slow LER. Zarrough et al. (1983) suggested that tall fescue could …
Determination Of Predictive Zones For The Evaluation Of Herbage Grasses In Cuba,
2025
Estacion Experimental de Pastos y Forrajes
Determination Of Predictive Zones For The Evaluation Of Herbage Grasses In Cuba, J Gerardo, Hilda Machado, Verena Torres
IGC Proceedings (1977-2023)
Regional studies that evolve a high quantity of environment are made nowadays in order to define the behaviour of a genotype in different environments, but the workers of introduction programmes can not prove their varieties in all environments. Therefore, it is necessary to select a wide range to represent production conditions. This topic has been studied by several writers (Rambling et al., 1980; Brown et al., 1983). The objective of our study is to reduce test sites due to the high source in income needed in these studies.
Varieties Evaluation Of Lucerne (Medicago Sativa) With Different Winter Dormancy Class,
2025
EEA
Varieties Evaluation Of Lucerne (Medicago Sativa) With Different Winter Dormancy Class, O A. Bruno, R J. Leon, L A. Romero, O R. Quaino
IGC Proceedings (1977-2023)
Lucerne, pure or as a component of mixtures, is the forage more used in many regions of Argentine. In the central part of Santa Fe province it is the basis of feeding in the milk production systems. The diffusion of this species was done by mean of populations, that at the beginning of this century produced forage of high yield, quality and good persistency. Later, the area ofland cultivated fluctuated, characterized by periods of diminishing and recovery. From 1969 the appearance of Pea aphid (Acyrthosiphum pisum) gave rise to a critical situation. The solution to this problem was …
L’Effet Du Climat Sur La Production Des Herbages,
2025
Universite d'Agronomie
L’Effet Du Climat Sur La Production Des Herbages, I Vinczeffy
IGC Proceedings (1977-2023)
Dans les regions arides on peut optimiser la production des herbages par une technologie adaptee au climat, meme dans des sols pauvres. Le climat de la Hongrie est en grande partie sec, Jes sols des herbages sont defavorables, la vegetation est degradee et l'effet des engrais est modere. Le rapport entre le climat et la production est presente par Jes donnees du ne traitement d'une experience de 9 ans.
Effects Of Temperature And Photoperiod On The Extension Growth Of Six Temperate Grasses,
2025
University of Alberta
Effects Of Temperature And Photoperiod On The Extension Growth Of Six Temperate Grasses, G.A Van Esbroeck, Jane R. King, V S. Baron
IGC Proceedings (1977-2023)
In western Canada late season pasture yields vary considerably among species. During August and early September yields of Bromus riparius and Dactylis glomerata are double that of the more commonly grown Bromus inermis (Knowles and Sonmore, 1985). The importance of leaf area to crop growth rate pnor to canopy closure is well documented (Rhodes, 1973). Two components of leaf area are the final size of leaves and the rate of leaf appearance, with final size of leaves largely dependant on the rate of extension and duration of extension (Edwards, 1967). Since the maturity of a leaf is closely associated with …
