Screening Tropical Forage Grasses For Resistance To The Spittlebugs (Homoptera: Cercopidae),
2024
EMBRAPA/CNPGC
Screening Tropical Forage Grasses For Resistance To The Spittlebugs (Homoptera: Cercopidae), J R. Valerio, A P. De Souza
IGC Proceedings (1977-2023)
Spittlebugs are the most damaging pasture pests in tropical America where extensive monocultures of Signal grasses, especially Brachiaria decumbens cv. Basilisk, have favored the buildup of spittlebug populations. Under severe spittlebug attack, the entire above-ground portion of the plant dries and eventually dies, thereby reducing the carrying capacity of infested pastures. Host plant resistance is a low-cost method of controlling spittlebugs. High level of spittlebug resistance is found in the cultivar Marandu (B. brizantha), but it requires more fertile soils. Brachiaria germoplasm is being screened for spittlebug resistance. In the present study, 30 introductions of Brachiaria were evaluated for …
Indicators Of Pathogen Potential Of Pasture Soils,
2024
Grassland Research Centre
Indicators Of Pathogen Potential Of Pasture Soils, R A. Skipp, R N. Watson, G C.M Latch
IGC Proceedings (1977-2023)
A simple pot test was used to indicate the combined effects of several pathogens common in pasture soils (plant parasitic nematodes and pathogenic fungi e.g. Pythium spp.) by comparing the dry weight yields of clover seedlings grown in untreated soil with those from soil treated in a microwave oven. Response to microwave treatment, expressed as a "Soil Pathogenicity Index", was greater with soil from old pasture or from areas in 2 year old pasture plots showing poor regrowth after grazing of white clover (Trifolium repens L) or Caucasian clover (T. ambiguum Bieb.), than from soil from new pasture or …
Impact Of Virus Resistance On White Clover Persistence And Productivity,
2024
USDA, Agricultural Research Service
Impact Of Virus Resistance On White Clover Persistence And Productivity, G A. Pederson, M R. Mclaughlin
IGC Proceedings (1977-2023)
The objective of this study was to compare the virus-resistant white clover (Trifolium repens L.) germplasm SRVR with virus-susceptible cultivars for productivity and persistence under clipping in several different environments. Four cultivars and SRVR were broadcastseeded in the field at Mississippi State, MS in the fall of eight different years. Dry matter yields were taken for 2-4 years after seeding using mowers for defoliation. Virus-resistant SRVR had greater dry matter yields than all four cultivars in the second year, greater than three of four cultivars in the third year, and greater than two of four cultivars in the fourth …
Appearance And Movement Of Fungal Endophyte In Annual Ryegrass,
2024
Texas A&M
Appearance And Movement Of Fungal Endophyte In Annual Ryegrass, L R. Nelson, Chunguang Du
IGC Proceedings (1977-2023)
In this study we investigated the efficiency of fungal endophyte (Acremonium loliii) transmission from plant to seed in annual ryegrass (Lolium multiflorum). Results indicated that the endophyte begins to move up or grow up the plant at about growth stage 30 of Zodoks scale, when day temperatures were near 25° C. In our study, we found that the endophyte was not transmitted to all seed for two reasons. Most importantly, the endophyte was not transmitted into some seedheads even though the plant was infected, indicating the tiller was not infected. Secondly in some infected seedheads, a very small number of …
Influence Of The Fungal Endophyte Acremonium Lolii On Dry Matter Yield Of Perennial Ryegrass In Galcia, Spain,
2024
Centro de Investigaciones Agrarias de Mabegondo
Influence Of The Fungal Endophyte Acremonium Lolii On Dry Matter Yield Of Perennial Ryegrass In Galcia, Spain, J A. Oliveira, J Collar
IGC Proceedings (1977-2023)
A field experiment studying the impact of the ryegrass endophyte (Acremonium lolii), was carried out at two locations in Galicia (Northwest Spain): Mabegondo on the Atlantic coast and Puebla de Brollón in the interior. Of 56 half-sib families of Galician perennial ryegrass (Lolium perenne L.) studied, 28 held endophyte (E+) and the other 28 not (E-). All these families were established in trial plots in 1992. Significant differences between E- and E+ families were obtained, and E+ families had a higher (P < 0.05) first cut, spring and total yield than E- families at Puebla de Brollón (dry location) in the third year after planting. The infection of perennial ryegrass with some strains of A. lolii seems to benefit the host in stressful conditions. In some areas of Galicia, climatic conditions are often stressful for perennial ryegrass and the chances of E+ plants being favored by either natural or artificial selection seems high.
Insecticidal Activity Of N-Formylloline,
2024
University of Kentucky
Insecticidal Activity Of N-Formylloline, D L. Dahlman, M R. Siegel, L P. Bush
IGC Proceedings (1977-2023)
Several insect species were sensitive to N-formylloline, a pyrrolizidine alkaloid found in significant concentrations in tall fescue (Festuca arundinacea L.) infected with Neotyphodium coenophialum (= Acremonium coenophialum) Glenn, Bacon et Hanlin. Topical or injected doses were toxic in a dose dependent manner. Acute doses resulted in quick incapacitation; lower doses caused behavioral changes, uncoordinated movements, tremors, etc. Insects tested included green bug, bird cherry-oat aphid, large milkweed bug, spined soldier bug, American cockroach, house fly, face fly, cat flea and Japanese beetle.
Autecology Of Prosopis Caldenia (Burk.) In The Region Of "Caldenal" Of The Province Of San Luis, Argentina,
2024
F.I.C.E.S-U.N.S.L.
Autecology Of Prosopis Caldenia (Burk.) In The Region Of "Caldenal" Of The Province Of San Luis, Argentina, G E. Gabutti, M.J L. Privitello
IGC Proceedings (1977-2023)
Different estimates of the growth of Prosopis caldenia (Burk.) were related in the area of the “caldén” forest, Province of San Luis: trunk diameter, treetop coverage and total tree height to infer the annual growth percentage. The number of trees per hectare and their distribution was calculated based on size. Pod production per hectare was evaluated to determine forage potential.
Variation In The Stylosanthes Anthracnose Pathogen: Implications For Australian Cultivars,
2024
CSIRO
Variation In The Stylosanthes Anthracnose Pathogen: Implications For Australian Cultivars, Sukumar Chakraborty, Ross Perrott, Maria Jose D'A Charchar, Celso D. Fernandes, Segenet Kelemu
IGC Proceedings (1977-2023)
Isolates of Colletotrichum gloeosporioides which cause anthracnose disease in the tropical pasture legume Stylosanthes were collected from its centre of diversity in South America. These and other isolates from Asia, Africa and Australia were studied using Random Amplified Polymorphic DNA (RAPD) markers and virulence on host differentials to assess the threat to Australian Stylosanthes cultivars from exotic races of this pathogen. A phenetic analysis of 90 isolates using RAPD markers showed a wide genetic diversity in the overall pathogen population. Compared to this, genetic diversity in the Australian population was very limited. A similar situation was noted for pathogenic variation …
Pfra Grazing Management Conserves Biodiversity,
2024
PFRA
Pfra Grazing Management Conserves Biodiversity, B Bristol, T Weins
IGC Proceedings (1977-2023)
Shrinking grassland habitats across Prairie Canada are resulting in increased societal values for biodiversity within the remaining rangeland resources. The Prairie Farm Rehabilitation Administration (PFRA) manages 929,000 hectares in the Prairie and Boreal Plain Ecozones across three Prairie Provinces. Management of these range resources accomplishes two main objectives: (1) sustaining economic viability of the rural community through provision of livestock grazing and (2) conservation of soil, water and biodiversity resources. PFRA uses the tools of inventory, research and management to accomplish these objectives. The 87 pastures are managed toward the “good and excellent” range condition classes which conserves biodiversity and …
Study Of The Diversity Of Soil Animal Community In The Songnen Plain Grassland Of China,
2024
Northeast Normal University
Study Of The Diversity Of Soil Animal Community In The Songnen Plain Grassland Of China, Yin Xiuqin, Zhu Tingcheng, Zhong Weiyan, Peng Wu Kui
IGC Proceedings (1977-2023)
This paper makes a diversity study of 8 habitats of soil animal communities in Songnen plain grassland. The research shows that the better the habitat condition is, the higher the diversity index of soil animals, and the worse the habitat condition is the lower the diversity index of soil animals. The diversity of soil animal communities has a positive relationship with soil organic matter, total nitrogen, and has a negative relationship with pH value. It has no obvious relationship with soil water content and total phosphorus. The diversity of soil animal communities decreases with increasing depth of soil layer and …
Clipping Intensity Impacts On Root Mass Variation Of Cool Season Grasses,
2024
University of Rhode Island
Clipping Intensity Impacts On Root Mass Variation Of Cool Season Grasses, D L. Stetson, W M. Sullivan
IGC Proceedings (1977-2023)
Seasonal changes in grass root and mat weight density were documented under different cutting managements. Kentucky bluegrass (Poa pratensis L.) and tall fescue (Festuca arundinacea Schreb.) received one annual cut, twice yearly forage harvest, and mown turf treatments. Orchardgrass (Dactylis glomerata L.) received one annual and twice yearly cutting treatments. Soil cores were collected to a 15 cm depth and divided into 7.5 cm increments. Roots and mat were recovered, washed, dried and weighed. Differences in years, seasons, species, treatments, and soil depth significantly influenced total root weight density and fine root density. With all species and …
Effect Of Grazing And Soils On The Structure Of Mountain Vegetation Communities,
2024
Banchory Research Station
Effect Of Grazing And Soils On The Structure Of Mountain Vegetation Communities, I Alonso
IGC Proceedings (1977-2023)
The range of life forms of four grassland communities in the Cantabrian mountains (N. Spain) was studied under grazing and when grazing was excluded in relation to soil characteristics. Hemicryptophytes were the most abundant life form in all communities and they increased their number when ungrazed. Diversity was bigger in the communities with shrubs, which presented a more heterogeneous structure. As a whole, grasslands on calcareous soils were more diverse than those on siliceous soils.
Increasing Grassland Biodiversity Within The Environmentally Sensitive Areas Scheme In The U.K,
2024
ADAS Bridgets
Increasing Grassland Biodiversity Within The Environmentally Sensitive Areas Scheme In The U.K, S Peel
IGC Proceedings (1977-2023)
The ESA scheme is the main vehicle in the UK for increasing biodiversity on agricultural land. It is voluntary, and payments are made to compensate for reduced profitability when prescribed practices are followed. These include conversion of cropping land to grassland, zero fertiliser use and late cutting for hay. The scheme is supported by an R & D programme aimed particularly at practical problems arising from the need to reconcile environmental targets with the need to maintain viable and profitable livestock systems. The paper cites examples of this R & D, including choice of seeds mixtures, the role of soil …
Depression On The Hygrophytic Weed In Pasture Establishment With Consideration To Wildlife Habitat,
2024
Kitasato University
Depression On The Hygrophytic Weed In Pasture Establishment With Consideration To Wildlife Habitat, T Sugiura, H Kobayashi
IGC Proceedings (1977-2023)
We investigated the influences of lower ground water level on the hygrophytic weed which luxuriated at the abandoned paddy field as a pasture establishment method in wetland with consideration to wildlife habitat. In comparison with the control, the leaf of common reed (Phragmites communis Trin.) at the drainage area was decreased by the 60% in weight and distributed at lower layers due to water stress. The photosynthetic rate of the common reed was also decreased by 64%. At the end of the growing season, the botanical composition began to include more short type species.
Genetic Diversity In The Native Australian Grass Agrostis Adamsonii (Poaceae),
2024
Royal Botanic Gardens Melbourne
Genetic Diversity In The Native Australian Grass Agrostis Adamsonii (Poaceae), E A. James, A Brown
IGC Proceedings (1977-2023)
Genetic variability in A.adamsonii is assessed from measurements of mature florets and from analysis of variation in DNA using the random amplified polymorphic DNA (RAPD) technique. Results are compared to those for three other species of Agrostis growing at the same site or in similar habitats.
Medicinal Plants As Indicators Of Grassland Biodiversity,
2024
Debrecen Agricultural University Department of Rural Resource Management Debrecen
Medicinal Plants As Indicators Of Grassland Biodiversity, G Nagy, I Vinczeffy, K Peto
IGC Proceedings (1977-2023)
A study has been made to identify the medicinal plants on the existing Hungarian grasslands. Sixty-three plants have been found to possess medicinal effects. Twenty-six, 15 and 22 species are for internal, internal or external and external use, respectively. This result reflects the low management intensity of grasslands in the country, as well as the species richness of semi-natural grasslands. It is suggested that the number of medical plants on the grassland, - in general - can also be used as an indicator of grassland biodiversity.
Sculpted Seeding: A Plant Community Approach To Revegitation,
2024
USDA- Soil Conservation Service
Sculpted Seeding: A Plant Community Approach To Revegitation, E T. Jacobson, D B. Wark, R G. Arnott, R J. Haas, D A. Tober
IGC Proceedings (1977-2023)
The sculptured seeding technique, an ecological approach to revegetation based on a knowledge and understanding of the natural vegetation of an area, establishes a diverse, effective native plant community capable of regeneration and plant succession. It is intended to match site capability with plant species known to thrive under particular conditions. Sculptured seeding is an option available to land managers interested in establishing and maintaining adapted native species and ecotypes within the limits of current technology and available seed sources. Field procedures for sculptured seedings are quite simple, involving only minor modifications to standard planting methodology. Seed mixtures based on …
Graded Management Intensity Of Grassland System For Enhancing Biodiversity On A Species And Landscape Scale,
2024
Swiss Federal Research Station for Agro-Ecology and Agriculture
Graded Management Intensity Of Grassland System For Enhancing Biodiversity On A Species And Landscape Scale, E Meister, B Koch
IGC Proceedings (1977-2023)
The objective of our research is to maintain and enhance wildlife resources, landscape diversity and economic competitiveness of grassland-ruminant systems. This may be accomplished by a diversified, graded management intensity of pastures and meadows (Dietl,1990), resulting in a network of intensively and extensively used grassland and other semi-natural habitats. Botanical diversity is thus increased on both a habitat and landscape level. In intensively farmed regions it may be necessary to re-establish species-rich grassland types and adjust management intensity to the site conditions and species’ requirements.
Mineral Contents Of White Clover Grass And Nitrogen Fertilized Grass Pastures For Lambs,
2024
Institute of Animal Production, Finland
Mineral Contents Of White Clover Grass And Nitrogen Fertilized Grass Pastures For Lambs, R Sormunen-Cristian, P Nykänen-Kurki, J Peltola
IGC Proceedings (1977-2023)
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 …
A Predictive Model Of Vegetation Dynamics Under Grazing,
2024
Macaulay Land Use Research Institute
A Predictive Model Of Vegetation Dynamics Under Grazing, C.P. D. Birch, B R. Werkman, L W. Partridge
IGC Proceedings (1977-2023)
This quantitative model predicts changes in the species composition of grazed vegetation. It is based on growth equations for each species represented. The three parameters in each equation represent maximum production rate, maximum standing biomass, and the decline of production rate at high total plant density. Parameters may be varied with environmental factors. The model is generic, but is illustrated using values for four taxa growing under red deer (Cervus elaphus) grazing on the Isle of Rhum, Scotland: bent/fescue grassland (Agrostis/Festuca), purple moor-grass (Molinia caerulea), mat-grass (Nardus stricta) and heather (Calluna …
