Agronomy and Crop Sciences Commons^™

Some Results Of Selection For Disease Resistance In Herbage Legumes At Svalof, Sweden, Bengt Andersson

IGC Proceedings (1977-2023)

Herbage legumes are very important for forage production in Sweden. One of the main problems when growing red clover and lucerne is their susceptibility to diseases of which the most important are stem nematodes, verticillium wilt, clover rot and root rot. Breeding for improved disease resistance has for a long time been one of the principal objectives in breeding programmes. The first successful result was obtained when a red clover cultivar resistant to stem nematodes was released. By the development of efficient laboratory, screening methods it is nowadays possible to introduce nematode resistance in all new cultivars of red clover …

An Interdisciplinary Approach To Breeding Bloat-Safe Forage Legumes, B P. Goplen, R E. Howarth, G L. Lees, K J. Cheng, W Majak

IGC Proceedings (1977-2023)

This paper reviews the progress of bloat research carried out in Canada over the past 20 years to clarify the etiology of bloat, identify bloat-safe characteristics in forage legumes, and develop techniques to breed a bloat-safe cultivar of alfalfa. To this end a number of research institutions have been involved and a number of diverse and complementary disciplines have contributed.

Mean Aspects Of Lucerne Breeding Work Practiced At The Forage Crop Institute In Lodi, P Rotili

IGC Proceedings (1977-2023)

The choice of mother plants and the progeny test had to be made in dense sward. This proposition is most important chiefly when the construction of the new cultivars concerns an intensive forage system like that of the Northern and Central Italy plains. In these conditions, being possible to control the major part of natural environment factors, the effects of artificial factors introduced by the farmer, become predominant. Among these, the high number of cuttings (six per year) is the most important. The major point for a breeder is to improve the lucerne meadow structure. The choice of the plant …

Heterosis Effect In Advanced Generations Of Synthetic Varieties Of Alfalfa, M Seki, F Fujimoto, S Inami, M Kanbe

IGC Proceedings (1977-2023)

Heterosis effect in advanced generations of synthetic varieties of alfalfa, Medicago sativa L., using component lines bred for one breeding objective and those using unrelated component lines for different objectives was investigated. Heterosis effect in yield in advanced generations of synthetic variety composed of unrelated lines selected from different varieties were higher than that of synthetics composed of lines from the same variety. In synthetics composed of selfed lines, component lines more than 6 seem to be necessary to avoid inbreeding depression. Futhermore, even with parents from maternally selected lines inbreeding would be unavoidable when lines are closely related. Considering …

The Release Process And Initial Adoption Of Andropogon Gayanus In Tropical Latin America, J E. Ferguson, C Sere, R R. Vera

IGC Proceedings (1977-2023)

Following introduction into Colombia in 1973, Andropogon gayanus CIAT 621 has been evaluated within various countries by many institutions and researchers. Between 1981-1985 it has achieved the status of a cultivar by a formal release process within Colombia, Brazil, Panama, Peru and Venezuela as Carimagua 1, Planaltina, Veranero, San Martin and Sabanero, respectively. The release process evolved independently in each country. The decision to release was taken by a single institution, except in the case of Panama. Each country elected to give a different name to an equivalent cultivar. Ample supplies of basic seed generally were made available, especially in …

Domestication Of Phalaris Aquatica As A Pasture Grass, R N. Oram, H E. Schroeder, R A. Culvenor

IGC Proceedings (1977-2023)

The Australian cultivar of phalaris (Phalaris aquatica L.) is a wild Mediterranean population that has been useful for increasing and stabilizing pasture productivity in south-eastern Australia, but it has many deficiencies. This review describes the discovery and exploitation of the genetic variation needed to domesticate and improve the species. Domestication began with the reduction of dimethyltryptamine alkaloids in the herbage. However, the low alkaloid cultivar, Sirolan, is still toxic, possibly due to hypomagnesaemia. The second domestication step is the suppression of seed dispersal. At least four recessive genes and dominance modifiers appear to control the non-shedding trait. These are …

Collecting And Breeding Legumes For Brazilian Tropical Pastures, E M. Hutton, F B. De Sousa

IGC Proceedings (1977-2023)

Brazil has a wealth of native legumes in Stylosanthes, Centrosema and Zomia in soils with pH 4.2-6.5. Collection of those with pasture potential is needed before elimination by agricultural development. Main ecological zones for legume collection include the Cerrados, Amazonia and the Caatinga. Acid-soil factors determining legume adaptation are discussed. Efficient root absorption in the presence of high Al saturation is critical. Increased Ca migration into subsoils through the use of appropriate compounds in needed. Native legumes like Stylosanthes species from areas with pH 4.2-5.4 have potential for oxisols-ultisols. Anthracnose resitance is essential in all Stylosanthes species, and …

Variation In Photoperiodical Response Of Heading In Italian Ryegrass (Lolium Multiflorum Lam.), H Yamaguchi, Shigeru Suzuki

IGC Proceedings (1977-2023)

The response of heading to short day and low temperature has been studied in 48 lines of Lolium species grown under four photoperiod conditions. After fully vernalized in field, materials were grown under four conditions: 24 hours at high and natural temperatures, 13 hours and natural daylength. The number of days from beginning of treatment to flag leaf expansion was recorded. We considered response to short day (RSD), response to low temperature(RLT), and earliness in a narrow sense as three important components controlling heading behavior after vernalization. RSD was measured by difference of the number of days to flag leaf …

A Method Of Accelerating Generation-Cycles In Orchardgrass, F Ikegaya, S Kawabata, S Sato

IGC Proceedings (1977-2023)

advance two generations a year was designed and demonstrated by using two cultivars with different maturity. The method consisted of the following five procedures; 1) growing of seedlings under 24 hr day-length at day/night temperature of 25°C/15°C, 2) floral induction treatment under 10 hr day-length at 10°C, 3) promotion of the period from inflorescence differentiation to seed ripening under 24 hr day-length at the temperature which increased gradually from 15°C to 24°C, 4) air-drying of freshly harvested seeds at room temperature, and 5) breaking of seed dormancy by prechilling at 50°C.

Germinable seeds were obtained from more than 90 percent …

A Dimorphic Pollination System In A Potentially Valueable Semi-Arid Pasture Legume, The Psoralea Patens Complex, E J. Britten, Ian S. Dundas

IGC Proceedings (1977-2023)

A closely related group of leguminous plants in the genus Psoralea has been reported to be potentially useful for pasture in the semi-arid tropics and sub-tropics of Australia. Attempts to produce seed for research purposes were frustrated by seed failure in certain lines while other lines produced seed freely. Examination of meiosis, pollen production and embryo development indicated no abnormality leading to seed failure. Pollination experiments by hand manipulation showed self incompatibility not to be the cause of poor seed set. Close examination of the structure of the flowers disclosed two types of stigmas. The stigmas of the free seeding …

Grass-Legume Associations And Breeding For Yield, L Zannone, R Paoletti, C Scotti, P Jacquard

IGC Proceedings (1977-2023)

The results obtained at the Forage Crops Institute of Lodi concerning binary grass-legume associations are discussed. The experiments were realized either in greenhouse or in field with different techniques. Varieties were grown in association and in pure stand. The nature of inter-specific interference proved to be the same as the intra-specific interference; its interpretation is based on the biological density hypothesis (Rotili, 1979). Within the grass-legume associations situations of competition with overcompensation are created alternatively in favour of one species or the other, depending upon their earliness and biological cycle. The overcompensation effects are cumulated, bringing to an agronomical advantage …

Using Acid Soil Selection To Develop Alfalfa Cultivars, J H. Bouton, M E. Sumner

IGC Proceedings (1977-2023)

Since alfalfa (Medicago sativa L.) is very sensitive to acid soils, it is logical to question whether alfalfa cultivars selected for acid soil tolerance will be as productive as cultivars selected in limed fertile soils when tested under production schemes which exhibit a range of soil pH and fertility conditions, especially in the subsoils. In this paper, the value of acid soil selection for developing alfalfa cultivars productive in both limed and acidic soil profiles are reported. Selection in acid soils was found to be better than selection in limed, fertile soil for developing alfalfa germplasms more productive in …

Competitional Effects Of Neighbor Plants And Genetic Variations In Experimental Populations Of Timothy, Phleum Pratense L., Y Shimamoto, Ch Tsuda

IGC Proceedings (1977-2023)

Genet and Ram et populations of timothy, Phleum pratense L., were raised to investigate the effects of neighbour plants on their growth. The adjoining plants were positively or none correlated in Ramet and negatively or none done in Genet populations in a number of traits. In number of tillers at both the first and second cuts negative and none correlation coefficients between the adjoining plants were observed in Genet and Ramet populations, respectively. Also competitional effects were obviously distinguished in dry weight of Genet population at both first and second cuts. Thus competitional variances for these characters were significantly observed …

Acid-Soil Tolerant Hybrids In The Tree Legume, Leucaena, E M. Hutton

IGC Proceedings (1977-2023)

Leucaena Jeucocephala (Lam.) de Wit is adapted to less acid and alkaline soils. It is potentially valuable for the American tropics, but much of this vast area has low pH soils (oxisols and ultisols) with high Al and low Ca saturations. Adaptation to these conditions needed sources of acid-soil tolerance in Leucaena and a definition of the characters basic to this tolerance. A field trial at Carimagua (Colombian llanos) indicated that subsoil Ca rather than Al was the main factor in Leucaena adaptation. Consequently interspecific crosses mainly between L. leucocephala and acid-soil tolerant L. diversifolia (Schlecht) Benth. Hook. …

Evaluation Of Orchardgrass And Alfalfa For Its Nutritive Value And Voluntary Intake By Neutral Detergent Analysis, T Ishiguri

IGC Proceedings (1977-2023)

A series of trials has been carried out over a ten-year period to determine the ad lib. intake and digestibility of clipped orchardgrass and alfalfa fed at several growth stages to wethers. Forage and feces were fractionated into cell wall (CW) and cell content (CC) with neutral detergent solution, moreover the digestibility and the digestible amount of CW, CC were determined. The changing amount of digestible dry matter (D DM) in grass and legume related to the amount of digestible CC and indigestible CW, whereas digestible CW was observed to have little relation.

orchardgrass varied little between the first cut …

Seasonal Beef Performance On Au Triumph And Kentucky 31 Tall Fescue At Three Fungal Endophyte Infection Levels, J P. Pedersen, S P. Schmidt, C C. King Jr, C S. Hoveland, J A. Mcguire

IGC Proceedings (1977-2023)

Greatly improved performance has been reported from cattle grazing tall fescue (Festuca arundinacea Schreb.) free of Acremonium coenophialum Morgan-Jones and Garns compared to those grazing heavily infected tall fescue. However, cultivar effects and the effects of intermediate infection levels have not been adequately explored. Therefore, a 3-year grazing study was conducted in west-central Alabama to compare beef steer performance on non infected 'AU Triumph' and 'Kentucky 31' tall fescue at three levels of A coenophialum infection. A. coenophialum infection levels of 0% on AU Triumph and 1, 34, and 90% on Kentucky 31 resulted in average daily gains (ADG) …

Effects Of Fluidized Bed Combustion Residue Application To Reclaimed Mine Land On Yield And Composition Of Forage And Performance Of Grazing Steers, K O. Smedley, J P. Fontenot, V G. Allen, H D. Perry, O L. Bennett

IGC Proceedings (1977-2023)

Fluidized bed combustion residue (FBCR), a waste product resulting from the addition of limestone to coal prior to combustion, is high in sulfur (S) and has approximately 50% of the neutralizing capacity of limestone. Research was conducted to study effects of repeated applications of FBCR to pastures on forage yield and composition, and on performance and health of grazing cattle. Three treatments were applied in three replicated .81 ha pastures located on acidic reclaimed land which had been previously mined by mountain top removal. Treatments were control, dolomitic limestone (3380 kg/ha) and FBCR (6760 kg/ha), applied in split applications. Pastures …

Lamb Performance On Extended Season Grazing Of Brassica Pekinensis X B. Rapa, D W. Koch, F C. Ernst Jr, N R. Leonard, R R. Hedberg, J R. Mitchell

IGC Proceedings (1977-2023)

Brassica pekinensis X B. rapa var. tyfon was evaluated for its potential for extending the grazing season and utilization for finishing lambs. Tyfon was seeded without tillage in mid-July and grazing was initiated in each of two years about 70 days after seeding with lambs which had previously grazed clover-grass. A similar group was placed on a balanced ration of hay and grain. Tyfon maintained high quality throughout the grazing period, which was 45 days in 1983 and 68 days in 1984. Lambs gained an average 214 and 249 g day-1 in 1983 and 1984, respectively, on tyfon, while lambs …

Changes In Production And Quality With Plant Elongation And Maturity Of American Jointvetch, P Mislevy, F G. Martin

IGC Proceedings (1977-2023)

. Preliminary information indicates forage quality of American jointvetch (Aeschynomene americana L.) decreases rapidly with age. The purpose of this study was to determine the dry matter (DM) yield growth curve and changes in quality as plants elongated and matured. The study was conducted _at Ona, Florida in the summer of 1977 and 1978 when plants attained multiple heights of 15 cm. Plants were established m July and sampled, beginning at about 6 wks. They were clipped into se_cti?ns and analyzed for in vitro organic matter digestion (IVOMD) and crude protein (CP). Simultaneously with each clipping treatment a plot …

Qualitative Evaluation Of Spontaneous Forage Legumes Growing In Central Italy, S Arcioni, M Falcinelli, U Francia, F Lorenzetti, V Negri, F Veronsei

IGC Proceedings (1977-2023)

Several natural populations belonging to 13 different species of annual, biennial and perennial forage leguminous plants were evaluated at Perugia (Italy) for forage quality in 1983 and 1984. On the basis of the results relative to annual legumes, Medicago arabica, M. orbicularis and Trifolium subterraneum appeared interesting materials. For what biennial and perennial species are concerned, T. repens, Lotus corniculatus and L. tenuis which, as well known, are important forage plants in Central and North Europe and North America, showed high feeding values appearing of great interest also in Mediterranean environment.