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Screening Sericea Lespedeza Germplasm For Tannin Concentration In The Leaves And Herbage Palatability, J C. Petersen, J A. Mosjidis, N S. Hill

IGC Proceedings (1977-2023)

Several million hectares in the subtropical world are currently used as grazing land for beef and dairy cattle, how­ever, in many cases animal production is very low. To improve animal nutrition, cultivated legume species can be introduced. Sericea lespedeza has potential and could be utilized in the acid soils of the· subtropics. Generally, sericea is low in palatability and nutritive value because its leaves contain tannins, which have long been associ­ated with low intake and reduced digestibility. Tannins are responsible for an astringent or bitter taste caused by the pre­cipitation of salivary glycoprotein (Goldstein and Swain, 1963). Chopping or macerating …

Forage Crop Improvement Through Biotechnology, S S. Croughan

IGC Proceedings (1977-2023)

Bermudagrass (Cynodon dactylon) is a perennial forage grass grown on over 10 million ha worldwide. In the southern United States, it is used extensively for grazing and the production of hay. It is a well adapted grass, but improvements in traits such as forage quality and pest resistance are needed. Much vari­ation in the nutritional value exists between genotypes. Tissue culture offers a method for the production of improved germ­plasm. Most plants regenerated from callus cultures will vary from the original variety from which they were derived. This phenomenon is referred to as somaclonal variation and can be …

Apomixis And Sexuality In Brachiaria Decumbens Stapf., C B. Do Valle, Y H. Savidan, L Jank

IGC Proceedings (1977-2023)

Brachiaria decumbens Stapf is a perennial tropical forage grass, native to east African savannas. It was introduced to Brazil in the 1960's and is now widely cultivated over 30 million hectares in Central Brazil alone. The two commercial varieties are apomictic tetraploids (2n = 4x = 36), producing uniform progeny, and were selected for their high dry matter production and persistence on poor acid soils. They lack, however, resist­ance to spittlebugs (Deois spp., Zulia spp., Aeneolania spp.) and produce forage of low nutritive value, especially during the dry winter months. The absence of natural variability associated to apomictic reproduction has …

Use Of New Methods For Grass And Legume Breeding In Western Region Of The Soviet Union, R Dapkus

IGC Proceedings (1977-2023)

The climatic conditions of the Western region of the Soviet Union are favourable for grassland production which provides the major part of forage for livestock nutrition. In raising grassland productivity, new varieties play an important role. Adapted varieties with high yield potential must be used. For developing such varieties, the Fodder Crops Breeding Centre fbr the Western region of the Soviet Union was estab­lished at the Lituanian Agricultural Research Institute in 1972 on the basis of experience since 1922, when selection of herbage species was initiated there. During the past twenty years, breed­ing work has progressed rapidly. At present, breeding …

Overall Quality And Quantity Evaluations Of Native Ecotypes Of Crested Wheatgrasses Of Iran, B Peymani-Fard

IGC Proceedings (1977-2023)

Agropyron cristatum (L.) Gaertn (crested wheatgrass) is indigenous to central Asia including parts of the USSR, China, Afghanistan, Turkey and Iran (Bore, 1970). It is a perennial tufted grass which often grows naturally on stony slopes and calcareous soils. In very hot dry periods it tends to remain dor­mant but renews its growth as soon as its moisture supply returns to normal. It also survives the coldest temperature encountered in its area of adaptation (Rogler, 1960). The toler­ance of Agropyron cristatum to heavy spring grazing results from early root activity, early accumulation of leaf tissue and significant accumulation of carbohydrates …

The Potential Of Lolium Multiflorum X Festuca Gigantea Hybrids, M O. Humphreys, H Thomas, B F. Tyler

IGC Proceedings (1977-2023)

The potential for combining traits from broadly adapted Festuca with more highly specialised Lolium has been investi­gated for many years especially with regard to cytological behaviour (Breese et al., 1981). In the USA, efforts to increase the nutritive value of tall fescue through hybrids with ryegrasses succeeded in producing the variety Kenhy (Buckner et al., 1977). So far, Lolium/Fescue hybrids have not been able to compete commercially with more productive ryegrasses in intensive UK farming systems (Breese and Lewis, 1984). How­ever, with recent economic changes in European agriculture there is a need for more efficient, lower input grassland …

Comparative Study Of Some Varieties Of Cowpea I- Productivity And Nutritive Analysis, K M. Ghobrial, M A. Gabra

IGC Proceedings (1977-2023)

In Egypt, the serious problem of feed shortage, especially of green summer fodder suppresses the improvement of animal production. Therefore, dependence on improving local food and food resources for both animals and humans becomes a «must» for a right policy. The animal feeding system is depen­ding on the cultivation of berseem (Trifolium alexandrium L.). It produces annually around 4.81 million tons starch value/year and could cover the requirements of animals with surplus of 0.92 million tons starch value. However, in summer period, there will be at least a deficiency of 1.50 million tons starch value and most animals are …

Ontribution A L’Etude Des Especes Spontanees Du Genre Medicago L. En Algerie. Analyses Chimiques Du Fourrage Au Stade Vegetatif, Ratiba Goumiri, A Abdelguerfi, F H. Longo-Hammouda, S Oubchur

IGC Proceedings (1977-2023)

En Algerie, l'alimentation constitue le principal facteur limi­tant la production animale; son deficit en unites fourrageres (UF) est evalue a 3 milliards (Moskal, 1983). Elle est, outre son deficit, souvent de tres mau��aise qualite. La connaissance de la valeur alimentaire des fourrages est indispensable pour equilibrer au mieux !es rations, etablir des plants de rationnement adaptes aux besoins et valoriser le potentiel genetique du troupeau (Codron, 1986). Dans ce cadre et afin de caracteriser le materiel vegetal local, nous avons realise quelques analyses classiques sur des legumi­neuses du genre Medicago. Les especes de ce genre sont, en effet, appelees …

Introduction And Evaluation Of Tropical Forages In The Savannas Of Colombia, E A. Pizarro, L H. Franco, A Ramirez

IGC Proceedings (1977-2023)

The well-drained isohyperthermic savannas occupy an area of 98 million hectares, and are distributed in Colombia, Venezuela, northern Brazil, and Guyana. This extensive region of tropical America is characterized by a total wet season potential evapotranspiration of 901 to 1060 mn, an average monthly temperature in the wet season above 23.5 °C, and a wet season of six to eight months. The soils are Oxisols of low fertility and the predominant production system is extensive cattle ranching on native pastures of low nutritive value (Coch­rane et al., 1985). The Tropical Pastures Program of CIAT began a series of regional trials …

Centrosema Tetragonolobum- A New Tropical Pasture Legume For Acid Soils, R Schultze-Kraft

IGC Proceedings (1977-2023)

During one of the joint plant exploration missions between CIA T's Tropical Pastures Program and national research institutions which aim at building up a comprehensive inter­national forage germplasm collection for development of acid­soil tolerant cultivars (Schultze-Kraft, 1985), an unknow Cen­trosema species was collected. It is closely related to C. brasili­anum and was recently described as C. tetragonolobum (Schultze-Kraft and Williams, in press). Its natural distribution is restricted to the Orinoco region in Colombia and Venezuela between latitudes 4° and 6° N. At present 12 germplasm accessions are available. They were collected during 1984-86 on acid soils (pH 4.5-5.5) and in …

L’Amatante (Amaranthus Retroflexus L.) Comme Plante Fourragere, L Bosch, F Casanas, A.M.C Verdu

IGC Proceedings (1977-2023)

L'amarante est une des mauvaises herbes !es plus communes dans nos champs. Elle parvient a etouffer la culture principale si on ne la contr6le pas correctement. Elle a une germination maximale en fin de printemps et en debut d'ete, bien que la ger­mination continue pendant tout l'ete, favorisee par Jes hautes temperatures et la lumiere intense (Baskin et Baskin, 1977). Sa croissance rapide s'explique par le fait qu'il s'agit d'une plante en C-4 specialement efficace pour la captation de CO2 puis­qu'elle a des cloisons cellulaires tres minces (Longstreht et al., 1980). Elle presente aussi une remarquable capacite de repousse apres …

Morpho-Physiological Aspects And Nutritive Value Of Brachiaria Brizantha Cv. Marandu And Heteropogon Sp Affected By The Plants' Age, V. De B.G Alcantara, A.R P. De Almeida, P B. Alcantara, G Braun, E L. Caielli

IGC Proceedings (1977-2023)

Grazing pressure must be related to the pasture potential capacity of recovery. The measurement of leaf area index (LAI) is a way of evaluating that effect. Whatever the management, the main objective will be to allow pasture to reach a high LAI status and its' maintenance (Peterson, 1970). In elephant grass the stem/leaf ratio was used to indicate the dry matter production and indirectly indicates the grazing pressure (Rodrigues, 1984). Present experiment was done to evaluate the evolution of leaf area index (LAI), leaf/stem ratio (L/S), percentages of crude protein (CP), crude fiber (CF) and in vitro dry matter digesti­bility …

Genetic Engineering For Pastures, W J. Peacock

IGC Proceedings (1977-2023)

The flrst genetically engineered food products frolll hotticultural production systems are now enlering the Market and field trials of genetically engineered crop species are well advanced. We can expect that a range of crop cultivars, in which genetic engineering is n component of the breeding process, will soon go into broad ncre agriculture. Pasture species are nut far behind. Gene transfer systems are in place for a number of temperate and tropical pasture legumes and even for a few species of more dlrficult grasses. Genetic transfer systems are In place for a numoec of temperate and tropical pastvce legumes and …

N-15 Study Of Nitrogen Uptake By Tall Fescue Throughout A Spring Growth, J Salette, Marie-Laure Decau, Francoise Vertes

IGC Proceedings (1977-2023)

In previous works, nitrogen uptake by a grass sward during regrowth has been studied and modelled (Salette and Lemaire, 1981 ; Lemaire and Salette, 1984). In this study, the use of N- 15 labelled fertilizer allows differentiation of two nitrogen sources for the plant nutrition : soil and fertilizer.

Spring Nitrogen Uptake In Grass Swards In Relation To N Fertilizer Rates And Variation Between Years, J Salette, Marie-Laure Decau, G Lemaire

IGC Proceedings (1977-2023)

No abstract provided.

Factors Affecting Isotopic Fractionation During Nitrogen Fixation By Pasture Legumes, S F. Ledgard

IGC Proceedings (1977-2023)

The ¹⁵N natural abundance method for measuring N₂ fix­ation by legumes has compared favourably with other methods (reviewed by Shearer and Kohl, 1986). This method is based on the small difference in ¹⁵N abundance between nitrogen (N) derived from N2 fixation and N derived from soil. The pro­portion of legume N fixed from atmospheric N2 (PN) is cal­culated using :

PN = (o¹⁵Nref - o¹⁵N1egume)/(0¹⁵Nref - B)

where o¹⁵N is the per mil ¹⁵N excess over atmospheric N₂ ; ref is a reference plant which obtains all …

La Definition De La Date Optimale De La Premiere Pature De Quelques Especes Et Varietes De Graminees Fourrageres, B Rutkowska, E Lewicka, A Kolakowska

IGC Proceedings (1977-2023)

La rationalisation du piiturage depend aussi de la date de la piiture, particulierement au printemps, au moment de la pre­miere ou de la deuxieme piiture quand !es tiges floriferes des graminees commencent a se developper (Allerit, 1978 ; Gillet, 1980). On sait que la meilleure periode pour debuter le piiturage se situe lorsque les plantes ont 20-25 cm de hauteur, !es ani­maux mangent mieux et !es pertes par pietinement sont limi­tees. En dehors de cela !es resultats des experiences frarn;aise et suisse (Caputa, 1975; Gillet et al., 1980) montrent qu'a cette hauteur !es jeunes tiges floriferes ont une hauteur de …

Effect Of Nitrogen On Herbage Growth And Intake By Sheep In Continuously Grazed Swards Of Tall Fescue Genotypes, A Mazzanti, G Lemaire, F Gastal

IGC Proceedings (1977-2023)

Relatively little is known about the growth of tall fescue under continuous grazing. Most of reported works about herb­ age production in such a grazing management have been done with perennial ryegrass and with relatively high levels of nitro­ gen fertilisation (Hodgson, 1981 ; Bircham, 1981; Parsons et al., 1983). The effect ot the level N nutrition on growth of a continuously grazing sward has not been yet studied. On intermitently defoliated swards of tall fescue, Gastal & Lemaire (1988) have shown that with non limiting level of N nutrition the increase in dry matter production could be 4 or …

Stand Characteristics Of Irrigated Cocksfoot Regrowth And Leaf Area Increasing, M Duru, A Langlet, S Rouzies

IGC Proceedings (1977-2023)

For grasses, high leaf area index (LAI) extension rate is necessary to intercept much radiation and to increase the growth rate (Gosse et al., 1986). The LAI extension rate depends on stand status just after the cut : tiller density (Nelson and Zarrough, 1981), residual leaf area and reserves level (Smith, 1974), plant nutrition (nitrogen especially). We study the setting up of LAI for vegetative regrowths according to nitrogen nutrition and different stand status : tiller number and size.

Cinteique De La Croissance Foliarie Et Stolonifere D’Un Peuplement De Digitaria Decumbens Au Cours De La Repousse, P Cruz, G Alexandre, H Baudot

IGC Proceedings (1977-2023)

II existe en climat tropical un grand nombre de graminees fourrageres de type stolonifere. Parmi elles on retrouve de nom­breuses especes dans des genres tels que Digitaria, Cynodon et Brachiaria lesquels representent a eux seuls une tres grande proportion des surfaces herbageres des pays tropicaux, dont Jes iles de la Carai:be Dans ces especes, la production est le resultat de la croissanc de d��ux ense?1ble�� d'organes, feuilles et stolons, dans des pro­portions qm vanent fortement en fonction du temps de repousse et des saisons (Salette, 1971; Crespo, 1985). Connais­sant Jes differences dans la valeur nutritive de ces organes (Her­rera, 1979) …

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 …

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.

Seed Yield, Fodder Yield And Persistence In White Clover Cvs Of Different Origins. Results Of Trials Conducted At Lodi (Irrigated Po Valley), R Paoletti, C Locattello

IGC Proceedings (1977-2023)

White clover is the most important pasture legume in many EEC countries (white clover-ryegrass pasture system) and a good component of permanent and rotated polyphytic meadows in North Italy (irrigated Po Valley where the Ladino subspecies developed through self selection). The main char­acteristics of the species are N2 fixation and high nutritional value (quality). Therefore, white clover seed usage in the EEC is expected to still be important in the next decades. A number of performing varieties have recently been developed by EEC Research Institutes. An assessment of their seed production potential is necessary in view of self-sufficiency and consequent …

Analysis Of The Effect On N Nutrition On Dry Matter Yield Of A Sward By Reference To Potential Yield And Optimum N Content, G Lemaire, F Gastal, J Salette

IGC Proceedings (1977-2023)

Previous work has shown that the N content of a sward could be related to the dry matter accumulation during the course of the regrowth by the following equation : N % = a(Wtb, where W is the weight of aboveground biomass and N % the N concentration of dry matter (Salette & Lemaire, 1981). The coefficient a represents the N % for an aerial biomass of I t/ha, and b characterizes the degree of dilution of N during the regrowth. When b = 0, N % remains constant during the regrowth. If b = I, there is an increase …

Alimentation Minerale, Niveau Hydrique Et Utilization De L’Eau Par La Luzerne, Micheline Anneessens

IGC Proceedings (1977-2023)

L'eau est souvent un facteur limitant !es rendements puisque des problemes se posent au niveau de sa repartition dans l'es­pace et dans le temps. Aucune etude n'a encore montre comment dose et composi­tion d'engrais interagissent avec l'humidite du substrat sur ]'utilisation de l'eau par une plante fourragere forte consomma­trice de cette ressource.C'est dans ce but que le present essai a ete realise sur la luzerne.

Optimization Of Grassland Ecosystem Production By Anthropogenic Treatment, R Holubek, J Jancovic

IGC Proceedings (1977-2023)

Abundant amount of the new knowledge was gained by an intensive research of grassland ecosystem in Czechoslovakia and other European countries during last 25 years. It was con­firmed that under favourable humid conditions and sufficient macronutrients and micronutrients together with adequate N­fertilizing should be nearly reached ecologically conditioned level of potential productivity and dry matter or N-compounds yields should be increased by 100-200 or 200-300 per cent respectively (Velich, 1986). Introduction of scientific methods of controlled agricultural production together with higher landscape protection requirements, stability of ecosystems, quality and health­proved foods requirements have changed the traditional views to the nutrition …

Experiment Of Trace Elements Fertilizer Spraying On Sown Pasture, Tu Minyi

IGC Proceedings (1977-2023)

The application of compound phosphate in the way of rot­ationary fertilizing in sections in successive years kept the vig­orous growth of pasture composed of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) in the first several years after the pasture was grazed in 1981. But the pas­ture could not keep the growing vigour even with the same level of fertilization in the last two years. Considering the unba­lanced nutrition being one of the major reasons, a preliminary experiment of trace elements spraying has been undertaken in Nanshan Sown Pasture-land aiming at identifying if trace fert­ilizers …

Some Nitrogen Forms And Micronutrients In Silage Maize Leaves As Affected By Nk Fertilization And Liming, C.L F. Carranca, M A. Castelo Branco

IGC Proceedings (1977-2023)

The nutritive value of a forage depends on the quality which, in time, is dependent on protein, sugar, cellulose, fat and min­eral elements content. The existence of deficiencies may limit the maximum yield and also the quality. Several experiments have been carried out in order to study the effect of liming and NK fertilization on the nutrients uptake by silage maize and yields.

The Diagnosis Of Grassland Mineral Nutrient Status Through Herbage Analysis, J Salette, Lydie Huche

IGC Proceedings (1977-2023)

It appears more and more clearly that soil analysis is not sufficient to give a good approximation of the mineral status of grassland soils. In perennial crops leaf analysis and empirical critical levels are widely utilized. This grassland approach emphasizes the good results which can be obtained for nitro­gen, potassium, phosphorus not from leaf but from the whole herbage plant analysis. This paper deals with pure grass stands.

Modelling Nutrient Uptake By A Grass Sward: Long Term Studies Over Several Years, J Salette, Lydie Huche

IGC Proceedings (1977-2023)

Many experiments were conducted to assess the short term effects of fertilization management on nitrogen and mineral uptake of cut or grazed swards. One important work was performed to model the grass nutrition status during a regrowth (Salette, 1982; Salette et al., 1983; Salette et al., 1989), but for both a theoretical and practical point of view it is of great interest to evaluate the evolution of N and mineral uptake throughout all the years of a pasture life. This paper gives an analysis of nitrogen and mineral uptake dynamics during sev­eral years and proposes a model for sward N …