Plant Pathology Commons^™

Variability Of A Tropical Savannah And Its Influence On Management Practices And Animal Weight Gains, R R. Vera, B Rivera, J H. Weniger

IGC Proceedings (1977-2023)

The savannah of the Colombian and Venezuelan plains have been relatively well studied from a floristic point of view and several major plant communities are recognized (Blydenstein, 1967). Nevertheless, the potential contribution of these plant communities to ruminant production have not been studied, except for the largest of these associations, that of the well­drained high savannah. Paladines and Leal (1979) have shown that it has low carrying capacity and sustains low levels of ani­mal production both per head and per animal, despite moder­ate levels of primary productivity. In effect, animal weight gains range from 70-90 kg head-1 and 18-40 kg …

Yield And Quality Of Signal Grass Stockpiled At Different Dates, E A. Pizzaro, R R. Vera

IGC Proceedings (1977-2023)

The savannas of the 'Cerrado' region of Brazil extend over 20 % of the brazilian territory, supporting over 50 % of the beef cattle industry (Kornelius et al., 1979). During the long dry season there is a pronounced deficit of quality in the natural savannas; conserved and standing crops (Pizarro and Vera, 1980; Paiva et al., 1978; Vera et al., 1981) pure legumes stands have been tested successfully to supplement the native veg­etation (Tergas et al., 1983). Large leafy yields have been reported during the second half of the dry season (Vera et al., 1981 ; Pizarro et al., 1985). …

Comparing California Annual Grassland Management Beliefs With Evidence From The Field, R J. King

IGC Proceedings (1977-2023)

Annual grasslands in California's Mediterranean climate are generally believed to have been dominated by perennial grasses prior to European settlement (Burchan, 1957 ; Heady, 1977). Numerous exotic annual species have been introduced, natura­lized, and now dominate grassland communities. Overgrazing by domestic livestock and replacement by aggressive introduced annuals are regarded as the primary factors respon­sible for the displacement of perennial species. Range scientists and managers have established a doctrine that annual grasslands are now fundamentally different from perennial grasslands. The range management profession's current goal for proper grazing of annual grassland is simply to maintain adequate litter on the soil …

Study On The Grassland In The Yellow River Delta Of China, Zhou Guangyu, Li Xingdong

IGC Proceedings (1977-2023)

The Yellow River Delta is one of the three biggest deltas in China. It is situated in the northeast part of Shandong Prov­ince, from 37°20' to 38°12'N and from 118°30' to I 19°10'E. It is an important economic development area of Shandong Prov­mce. Grasslands are the main vegetation and the important agri­cultural resources in the Yellow River Delta. They had not been studied up to now, but for a long time they were reclaimed with the lack of management. According to the Vegetational Regination of China, this delta belongs to the warm temperate deciduous broad-leave) forest region (Wu Zhengyi et …

Distributions Of Yields And Nutritional Value In Native Pastures In South China, Zhiqiang Lai

IGC Proceedings (1977-2023)

There are about 40 millions ha of gqtzeable hill tussocky pastures in south China, generally with an elevation below 500 m and slopes between 6 to 30°. They are suited to ruminant animal husbandry with good rainfall, long growth period and a variety of high yielding plants. But most of the swards are improperly used and managed. This damages the pasture resources, and causes erosion due to overgrazing resulting in ecological unbalances and eventually, hazards the development of ruminant husbandry. The aim of this trial was, by studying the growth rhythm, seasonal distributions of the yield and nutritional value of …

Evoluation Et Perspectives De L'Etude Des Paturages D'Afrique Tropicale, A Gaston

IGC Proceedings (1977-2023)

L'elevage extensif est tributaire des problemes de sante anim­ale, d'abreuvement et d'alimentation. Apres la 2e Guerre mondiale, l'elevage tropical africain etait confronte a de graves epizooties qui maintenaient le cheptel a un niveau relativement bas. Cette cause, et Jes effets benefiques d'une periode a precipi­tations satisfaisantes faisaient qu'il y avait peu de problemes d'abreuvement et d'alimentation d'autant plus que la trans­humance etait pratique courante et facilitee par la faible implantation agricole. La prophylaxie a ete la priorite accordee a l'elevage. Les conditions climatiques permettaient !'existence de paturages de bonne qualite, mais certains etaient inutilisables par manque d'eau permanente. L'hydraulique pastorale …

The Influence Of Some Factors On The Production Of Mediterranean Pastures, M Espejo, J Bernardo, I Montero, L Garcia Barreto

IGC Proceedings (1977-2023)

In the grazing systems it is important to know the different methods for grass production with the objective of estimating the availability of pasture during the different seasons so as to adjust stocking rates and to make the necessary provision for the food shortage periods. There are several factors which influence pasture production, among them : type of soil, livestock, fertilization (Jimenez et al., 1976), climatology (Granda, 1981) and livestock manage­ment (Olea, 1982) are the most important ones. This work studies the influence of some of these factors under the environmental conditions of Southwest Spain.

Comportement Alimentaire D'Un Troupeau Ovin Dans Un Systeme , A Ben Boubaker

IGC Proceedings (1977-2023)

En Tunisie, pour freiner !'erosion et satisfaire Jes besoins pressants des animaux domestiques, des plantations de Acacia cyanophylla (Lindi) destinees a etre paturees ont ete creees. Pour rechercher une gestion rationnelle de ces parcours, nous avons etudie notamment le comportement des ovins dans un systeme « Acacia-herbe » partiellement fertilise. L'etude a ete realisee dans la region de Beja (Nord-Ouest de la Tunisie) sous climat mediterraneen sub-humide a hiver doux, sur sol brun calcaire (facies vegetal a Hedysarum coronarium L. et Phalaris truncata L.)

Etude De La Productivite Des Parcours De La Zone D'Ain Leuh (Moyen Atlas - Plateau Central), M Qarro

IGC Proceedings (1977-2023)

Les aires de parcours des troupeaux, ovins et caprins, des tri­bus du Moyen Atlas sont constituees essentiellement de quatre types de formation vegetales (Qarro, 1980) : Chenaie verte a oxycedre en climat semi-aride du Plateau Central, chenaie verte pure en climat sub-humide du Dir, cedraie a sous-etage de chene vert et pelouses d'altitude asylvatiques des montagnes mesatlasiques humides. Etagees le long d'un gradient altitudinal, pluvial et thermi­que, ces formations jouent un role complementaire au cours du cycle pastoral. Cette complementarite explique qu'elles consti­tuent un ensemble coherent, unifie par !es pratiques pastorales des tribus usageres. En general, la production en matiere …

Analyse De La Production Herbacee D'Un Paturage Boise Des Causses (Sud De La France), D Hubert, P Boglio

IGC Proceedings (1977-2023)

Les Grand Causses s'etendent sur 300.000 ha a une altitude variant de 700 a 1100 m. Ce sont des plateaux karstiques subis­sant des influences climatiques, oceaniques, mediterraneennes et montagnardes. La temperature moyenne annuelle est voisine de 8°C, la temperature moyenne des minimas du mois le plus froid est de 4°C !es precipitations sont de 1000 mm en moyenne. Le climat est remarquable par ses« exces » (amplitu­des thermiques, hygrometriques, violence des precipitations et du vent). Une grande partie du territoire (80 a 90 %) est couverte par des pelouses clairsemees se developpant sur des sols pauvres, superficiels, caillouteux. Ces sols …

Influence De L'Intensite Du Paturage Sur Le Cycle De Vie Des Especes Ligneuses D'Une Garrigue Du Sud De La France, M Kawas, C Floret

IGC Proceedings (1977-2023)

Le present travail a eu pour but de mettre en evidence l'effet du paturage sur les especes vegetales spontanees de formations vegetales ligneuses (garrigues) au Nord de Montpellier (France). La zone d'etude est situee d'apres le climagramme pluviothermique d'Emberger, dans l'etage bioclimatique medi­terraneen humide a hiver tempere Q = 132,9 ; m = 2,6 °C ; M = 27,7 °C; p = 961,8 mm). Ces garrigues sur sol calcaire dur ont ete soumises depuis des millenaires a !'impact de l'homme. Exploitees depuis longtemps, pour le bois, la culture et le paturage, et souvent brfi.lees, !es garrigues sont devenues des formations …

Year Round Protein Of Native Grasses Of Lesotho, C J. Goebel, G Seutloal, V Ramakhula

IGC Proceedings (1977-2023)

Rangelands of Lesotho are primarily located in the "sour veld " region of southern Africa. Percentagewise, the lands are cxtc11sive and furnish large quantities of forage for various type, of grazing animals. Detailed information upon nutritive qua I I ty of the native grasses would be of major benefit to assist in planning rotation grazing programs during critical periods or the year. In addition, there is a need for information of the nutrttional quality of introduced grasses to Lesotho's rangelands.

Dynamique Du Systeme Herbager Installe En Guyane Francaise, Mme Moise Bereau, J P. Gachet

IGC Proceedings (1977-2023)

En 1975-76, un « Plan de peuplement et de mise en valeur » de la Guyane Frarn;;aise est elabore. L'elevage bovin viande constitue un des elements essentiels du volet agricole et le choix est fait d'un systeme d'elevage intensif. En l'absence de references locales un programme de Recher­ches d'accompagnement est initie, c'est une Recherche dans le Developpement pour le Developpement.

Utilization De Parcours Par Des Ovins Laiteiers En Corse: Methodologie, Premiers Resultats, Florence Volaire, F Vallerand

IGC Proceedings (1977-2023)

En Corse, la deprise agricole du debut de ce siecle a favorise !'emergence et la multiplacation d'elevages en « extensification passive» qui, du fait d'une faible pression animale sur le milieu, ne permettent plus un controle de la dynamique vegetale (Per­net et Lenclud, 1977). Dans ce contexte ou le maquis progresse, la production herbacee spontanee est limitee et essentiellement printaniere. Les elevages ovins laitiers de semi-montagne pre­sentent ainsi un decalage chronique entre le cycle de la demande fourragere (maximum en automne-hiver du fait des mises-bas) et le cycle de l'offre permise sur parcours. Or ces derniers per­mettent de couvrir 90 …

Effect Of Slope Exposures On The Growth Of Tall Fescue And Bahiagrass In Subtropical Region Of Kyushu, M Ueno, Y Sugimoto, M Hirata

IGC Proceedings (1977-2023)

The effect of slope exposures on the development of veg­etation seems so obvious that its importance needs not be emphasized. For example, when a survey was made on old pastures at lowland hills in southern Kyushu, temperate region grasses dominated on north-facing slope, while subtropical grasses predominantly occupied swards on south-facing slope (Nikki et al., 1981). Slope exposure can have a marked influence on climatic factors (Lambert and Robert, 1976). The purpose ofthis paper is to describe some functional rela­tions between slope exposure influence relating to the microcli­mate and growth of cool season - or warm season grass species in …

Effects Of Straw Cover And Seed Burial On Changes In Hard Seededness Of Annual Medics, P E. Quigley, E D. Carter

IGC Proceedings (1977-2023)

Self-regenerating annual legumes, including subterranean clover and medics (Medicago spp.) are important pasture species in the cereal-livestock production zone of southern Australia and other Mediterranean climatic zones of the world. The pattern of germination in the genus Medicago, in which only a small percentage of seed germinates at one time because of hard-seededness has many ecological advantages particu­larly for the successful dissemination and colonization of medics. When medic pastures are incorporated into rotation systems with field crops the hard-seededness trait enables the medic seed population in the soil to survive periods of one, two or possibly three or more …

Seed Reserve And Self-Regeneration Of Annual Medic Pastures In A Mediterranean Environment, T E. Ameziane, M Mazhar, O Berkat

IGC Proceedings (1977-2023)

In the Mediterranean Basin, a growing concern towards the adoption of the South Australian dryland farming technology, known as the ley-farming system, is observed, particularly in countries of North Africa and West Asia. It is widely believed that tremendous agricultural productivity of these countries would result from the use of annual self-regenerating pasture legumes in rotation with cereals (e.g. Carter, 1978). However, it is also recognised that some targetted agronomic research should be conducted locally if transfer of this technology is to be feasible (Boyce et al., 1985; Mazhar, 1987). Field research involving the study of relevant principles of the …

Comportement Et Interet Herbager Du Sorgho Fourrager Conduit En Irrigue En Conditions Bioclimatiques Tunisiennes, B Taamallah Salem

IGC Proceedings (1977-2023)

Le bilan fourrager, en Tunisie, reste jusqu'a present tres deficitaire. On note un deficit de l'ordre de 456.000 UF en 1985 (ministere de I' Agriculture). Le grand deficit fourrager se concentre surtout pendant la saison estivale, saison seche et relativement chaude de l'annee. Plusieurs tentatives de redressement ont ete entreprises depuis plusieurs annees visant particulierement: la diversifica­tion des ressources fourrageres et la mobilisation des ressources disponibles en eau au profit de quelques cultures fourrageres. En effet, la construction de barrages dans quelques regions relativement pluvieuses en hiver encourage !es agriculteurs a tenter la conduite de certaines especes fourrageres en irrigue, …

The Study Of Grasses, Legumes And Other Forage Plants Germplasm Resources In Xishuangbanna Of Yunnan Province, China, Wu Renrun, Lu Xinshi, Zhang Deyin

IGC Proceedings (1977-2023)

Xishuangbanna Dai Autonomous Prefecture (XDAPJ is situated in Southern Yunnan, with an area of 19,220 km , being equivalent to 1/500 of the total area of China. The number of species in flowering, moss and fern plants altogether was esti­mated appriximately at 5,000 equalling to 1/6 of that in PRC, about as many as 1/3 of that in Yunnan. So that XDAP is well known as the « Green Treasure Land » throughout the country. Xishuangbanna lies at 21° !0'-22°37'N & 99°55'-101°50'E, consisting of 3 counties, Jinghong, Menghai and Mengla. The general topography is featured by higher in west and …

Adaptation Of Medicago Polymorphia To The Subhumid Mediterranean Zone Of Chile, A Del Poso, C Ovalle, J Avendano, P Del Canto

IGC Proceedings (1977-2023)

Annual medics (Medicago spp.) were accidentally introduced in Chile and to date have been reported six naturalized species in the Mediterranean zone: M. polymorpha, M. arabica, M. minima, M. orbicularis, M. turbinata and M. Lupulina, the first two being the most abundant. M. polymorpha is found over a wide range of bioclimatic

conditions, ranging from the arid Mediterranean zone (30° S), with 130 mm mean annual rainfall and neutral to alkaline soils, to the humid Mediterranean zone (38° S), with 1300 mm of pre­cipitation and moderately acid soils. M. arabica is often found growing together with M. polymorpha in the …

Desiccation Tolerant < Resurrection > Grasses For Dryland Areas, D F. Gaff

IGC Proceedings (1977-2023)

It has long been appreciated that seed of most plant species have protoplasm that survives full air-dryness. Unfortunately, this genetic capacity for desiccation tolerance is rarely expressed in the vegetative tissues of higher plants. Before 1970, only ten flowering plants had been reported to have leaf proto­plasm which could recover uninjured after becoming air-dry. In general, these were relatively rare species in families with little commercial importance. The discovery of a grass species with leaves, which were able to « revive» from air-dryness (Gaff, 1971), prompted the author to initiate a protracted search for other such desiccation tolerant grasses. This …

Regression Models To Assess Adapatation Of Annual Medics (Medicago Spp.) In Semi-Arid Subtropical Australia, N M. Clarkson

IGC Proceedings (1977-2023)

Annual medics improve production and quality of herbage in winter and are naturalised in inland eastern Australia to lat. 24° S. In southern inland Queensland (lat. 24 to 29 °S, mean annual rain 500 to 800 mm with two-thirds in summer), pro­ductivity of the summer-growing grass pasture is limited by rainfall and soil N in summer, and by low temperature and frost in winter. Thus, I tested medic as a self-regenerating win­ter forage component. Because rainfall is highly variable in our region, I also used rainfall over the past 120 years to estimate the production of medics and so provide …

Palatability Of The Main Fodder And Pasture Species Present In S.E. Spain: Ii. Herbaceous Species, A Robledo, E Correal, S Rios

IGC Proceedings (1977-2023)

In the cultivated areas of SE Spain there are many her­baceous species growing as weeds that represent a problem for farmers ; nevertheless, some of them are traditionally utilized by sheep and goats. Some of these weeds could be grown in combination with traditional crops to obtain supplementary feed for livestock ; to decide initially which of them have greater potential as fodder covercrops, a pen-feeding palat­ability study has been carried out.

Palatability Of The Main Fodder And Pasture Species Present In S.E. Spain: I. Woody Species (Trees And Shrubs), S Rios, E Correal, A Robledo

IGC Proceedings (1977-2023)

In S.E. Spain, livestock is mostly fed with the subproducts from cultivation of cereals. As a result of the limited feed resources available and because of the growth restriction imposed by climate, several feeding gaps occur along the year : at the end of summer, during winter, and at the end of spring. In a search of new fodder resources to cover the mentioned feeding gaps, a first step was to compare the palatability of the main fodder species present in cultivated and range areas.

Conversion Of Tropical Forest To Pasture In Latin America, H A. Pearson, Susanna B. Hecht, T E. Downing

IGC Proceedings (1977-2023)

A major workshop concerning the impacts of tropical forest conversion to pastures in Latin America was conducted in Oax­aca, Mexico, October 4-7, 1988, by the U.S. Man and the Bios­phere Program (MAB). The workshop described the current situation and history, reviewed the economic, environmental, and social impacts and dynamics of deforestation, discussed production alternatives and development perspectives, and identified research, technological, and policy options and priorities. The purpose of this paper is to summarize results and recommendations of the Oaxaca workshop and emphasize it significance at the XVI International Grassland Congress.

Environmental Related Variation In A Natural Grassland Of Rio Grande Do Sul, Brazil, V De P. Pillar, A.V A. Jacques, I I. Boldrini

IGC Proceedings (1977-2023)

Vegetation ecology studies help research efforts to improve natural grassland productivity by laying foundations for improvement techniques directed to benefit desired plant com­munities. Experiments reveal knowledge about the environ­mental conditions responsible for community structure and productivity, while surveys are a fast and cheap means for exploratory studies. In either case, data interpretation are helped by multivariate methods described by different authors, e.g., Orloci and Kenkel (1985). Our work is aimed to identify the environmental factors most responsible for vegetation variation in natural grasslands, locally known as « campos », and to formulate hypotheses about the effects of fertilization and grazing …

Introduction, Selection And Evaluation Of Annual Sown Forage Legumes Under Continental Mediterranean Climate Conditions In Pakistan, Asghar Ali, J.D H. Keatinge, B Roidar Khan

IGC Proceedings (1977-2023)

The upland areas (> 1000 m) of Baluchistan Province in Pakistan (Latitude 28-32° N) experience a continental semi­arid Mediterranean climate with some irregular additions of summer monsoonal rainfall. The current farming systems rely on the production of small ruminants from degraded Artemesia and Chrysapogon sp. rangeland and subsistence cropping of wheat/fallow rotations (Icarda, 1988). Sheep and goat numbers in Baluchistan have increased since 1955 from approximately two to thirteen million head in 1986 (Icarda, 1988). This has resulted in severely overgrazed rangelands and periodic acute feed deficits. In response the Arid Zone Research Institute has initiated a program for the …

Intensive Maize Production - The Basis For Intensification Of Cattle Production In Venezuela, J Cizec

IGC Proceedings (1977-2023)

The two main branches of cattle production in Venezuela are beef production and dairy production. Both branches are still rather extensive, mainly due to very extensive forage pro­duction. This is particularly evident in beef cattle production where almost 50 % of the weight gain achieved in the rainy season is lost during the dry period. Thus, it takes three to four years for the cattle to achieve slaughtering weight (Moore, 1970). On the other hand, relatively satisfactory milk production of dairy cows is enabled only by consumption of large quantities of expensive concentrates. Within an agricultural and industrial development project …

Study On The Eco-Biological Characteristics And Utilization Of Artemisia Growing On Arid Ranges, Shi Dingsui, Smayi Balaty, Xu Peng

IGC Proceedings (1977-2023)

Artemisia species are found in large areas of the Zhunger Basin, Tacheng Valley, Yili Valley, the northern slope of the Qulun mountains of Xingjiang ; the total area is larger than 6.67 million ha. The drought-enduring Artemisia has a high resistance to bad conditions and high protein and fat contents. Artemisia transiliensis Poljak at branched stage has 21.4 per cent crude protein, and the content of fat at the mature stage of seeds is 5.7 per cent. They are the best forages for lambs in early spring, autumn and winter, especially for fattening in autumn and milking in early …

Forage Production From Barley, Oats And Triticale Under Semi-Arid Conditions, D Droushiotis

IGC Proceedings (1977-2023)

Under Mediterranean climatic conditions and systems of Agriculture, cereals are important contributors to animal feed­ing. They are, in general more drought and cold resistant than forage legumes. Barley in particular is a very important forage crop because of its reliability and versatility. As interest in live­stock increases in this area, fodder production becomes more and more important. The limited rainfall makes it difficult to get away from cereals and they will, for a long time to come, continue to be a major source of grazing, freshly cut forage, hay, silage and grain-straw.