937 resultados para Bahia grass pollen
Resumo:
‘AGRD’ was selected by the breeder, Dr Warren Hunt, from a variant area of winter active turf (probably ‘Tifway’ or ‘Tifgreen’) on a Hong Kong Golf Course in Apr 1996. A selection of this material was imported through vegetative quarantine to New Zealand for evaluation. Following a favourable assessment of its potential as a warm-season turfgrass variety under New Zealand conditions made based on its superior comparative performance relative to other Cynodon accessions in glasshouse and field trials, the New Zealand registered variety ‘Grasslands AgRiDark’ was released in 1999. PBR Certificate Number 3716, Application Number 2004/299, granted 20 January 2009.
Resumo:
‘KP4’ is based on selected F4 progeny of 8 plants showing a low, creeping, tight-matted, late flowering growth habit. The original parental breeding population was selected from among 1600 diploid Rhodes grass seedlings grown as spaced plants; seven of the selected parental plants were from ‘Katambora’ and the eighth (which did not contribute as a maternal parent beyond the F1 generation) was a seedling from an unreleased accession. Four (4) cycles of mass selection were conducted, in which the selected plants from the previous generation were allowed to inter-cross in isolation in the field, and the resultant progeny later grown as spaced plants in the field for the next cycle of selection. Selection was for the following attributes: prostrate creeping early growth habit with short stolon internodes resulting in a dense stolon mat; leafy appearance; fine leaf and stem; and late flowering (i.e. a long period of vegetative growth before flowering). ‘KP4’ is a synthetic Rhodes grass cultivar multiplied from the selected fourth-generation plants produced by this line of breeding. Breeder: Donald S. Loch, Cleveland, QLD. PBR Certificate Number 3661, Application Number 2006/189, granted 16 December 2008
Resumo:
‘A-1’ was selected from a breeding population of 40 seedling Zoysia matrella plants from various parts of Southeast Asia (Japan, Philippines, China, Korea, Vietnam and Thailand). The original plants were vegetatively propagated and evaluated first in pots. A shortlist of selected genotypes was expanded to field plantings at Sheldon, QLD and evaluated against existing Z. matrella and Z. matrella x Z. japonica hybrid cultivars under mowing heights from 10 to 25mm and under shade levels ranging from 0 to 80%. ‘A-1’ showed higher tiller density and a more prostrate growth habit than the parent ecotype, and was selected from the subsequent breeding population on the basis of its superior turf colour and quality under mowing for 6 years and its shade tolerance as shown by its ability to maintain density of the mown sward under greatly reduced light levels (70-80% shade). Additional observations regarding climatic adaptation were made in Cairns, QLD, and Melbourne, VIC, respectively. Breeder: Donald S Loch, Alexandra Hills, QLD. PBR Certificate Number 3649, Application Number 2008/091, granted 16 December 2008.
Resumo:
Mastreviruses (family Geminiviridae) that infect monocotyledonous plants occur throughout the temperate and tropical regions of Asia, Africa, Europe and Australia. Despite the identification of a very diverse array of mastrevirus species whose members infect African monocots, few such species have been discovered in other parts of the world. For example, the sequence of only a single monocot-infecting mastrevirus, Chloris striate mosaic virus (CSMV), has been reported so far from Australia, even though earlier biological and serological studies suggested that other distinct mastreviruses were present. Here, we have obtained the complete nucleotide sequence of a virus from the grass Digitaria didactyla originating from Australia. Analysis of the sequence shows the virus to be a typical mastrevirus, with four open reading frames, two in each orientation, separated by two non-coding intergenic regions. Although it showed the highest levels of sequence identity to CSMV (68.7%), their sequences are sufficiently diverse for the virus to be considered a member of a new species in the genus Mastrevirus, based on the present species demarcation criteria. We propose that the name first used during the 1980s be used for this species, Digitaria didactyla striate mosaic virus (DDSMV).
Resumo:
Suitable for gaining some insights into important questions about the management of turf in dry times. Improve your product quality and avoid unnecessary losses. Can varieties help? How important are soils in conserving moisture and how do I measure my soil's condition? How can I make the best use of available water? Can water retaining amendments assist in establishing turf? Is recycled water a good option? Contains research results from turfgrass trials conducted by Queensland Government scientists for Queensland conditions.
Resumo:
The Horticulture Australia funded project, Management Guidelines for Warm-Season Grasses in Australia (TU05001), has allowed a detailed greens grass study to take place and enabled researchers and superintendents to work together to collect meaningful data on a range of Cynodon dactylon (L.) Pers. x Cynodon transvaalensis Burtt-Davy (Cynodon hybrid) and Paspalum vaginatum O. Swartz (seashore paspalum) cultivars suitable for golf or lawn bowls use. The end result provides superintendents and greenkeepers with additional knowledge to accompany their skills in managing or upgrading their greens to produce a denser, smoother and faster putting or bowls surface. However, neither turfgrass selection nor finely tuned management program will overcome unrealistic expectations (especially in relation to usage), poor growing environments, or limitations due to improper construction techniques.
Resumo:
The impacts of 4 grazing strategies (year-long grazing, summer grazing, winter grazing and winter grazing plus spring burning) on the grass:legume balance were studied between 2000 and 2006 in a pasture oversown with Stylosanthes scabra cv. Seca (Seca stylo) in central Queensland. Seasonal rainfall throughout the study was generally below average. Total pasture yields in autumn were higher in the 2 winter grazing than the 2 summer grazing treatments, largely reflecting the sampling time relative to when grazing occurred. There were few differences in Seca composition in autumn, although there was a clear trend for Seca composition to be reduced by winter grazing plus burning. Both the frequency of occurrence and plant density of Seca were higher under the 2 summer grazing treatments and there was also a trend for the density of juvenile plants (<5 cm height) to be higher in the 2 summer grazing treatments. Seca soil seed banks were generally low and were reduced in the winter grazing plus burning treatment in spring 2002. The frequency of the palatable perennial grass Pennisetum ciliaris (Biloela buffel grass) was reduced while that of the 'increaser' species Bothriochloa pertusa (Indian couch grass) and Stachytarpheta jamaicensis (snake weed) increased in the 2 summer grazing treatments compared with the 2 winter grazing treatments. Burning in spring increased soil loss in treatments grazed in winter. Differences in Seca frequency and density but not composition were explained by the 2 summer grazing treatments promoting 'gaps' in the pasture which were then colonised by Seca plants and other 'increaser' species. It was reasoned that, with time, mature Seca plants in the 2 winter grazing treatments would die so that Seca composition would eventually become higher under summer grazing regimes than under winter grazing. It was concluded that limiting grazing to particular seasons can alter legume:grass balance and that a time-frame of 5-8 years with average to good rainfall would be necessary to achieve large shifts in composition.
Resumo:
In western Queensland, severe drought conditions began in late 2001 and did not generally ease until the 2008/09 summer. Despite the ability of Mitchell grass plants to become dormant during drought, a large proportion of plants appeared to be dead rather than drought-dormant by the end of the 2002/03 summer. Tillers and remaining leaves were blackened and unpalatable to livestock. The term Mitchell grass dieback was coined by producers and other observers to describe what had occurred, although most were confident that the grass would recover with the breaking of the drought. Mitchell grass plants generally failed to respond to widespread average summer rains in early 2004 (> 250 mm). Observation suggested that moisture had penetrated to a soil depth of about 60 cm and a response from plants was expected. When there was no general response, research into the reasons for this was initiated (NBP.348 'Mitchell grass death in Queensland: extent, economic impact and potential for recovery'; 2005-07). This included an investigation of discrete areas of pasture that had responded to the 2003-04 summer rain. Further declines in condition of Mitchell grasslands occurred between winter 2005 and winter 2006 and, by 2006, field surveys indicated that 53% of this pasture community was in poor (C) condition, primarily due to dieback. Measurements at some sites suggested practices such as wet season spelling and burning can pre-condition Mitchell grass pasture for greater resistance to drought-induced dieback. However, the casual mechanisms and the effective timing and frequency of these practices remained unclear.
Resumo:
Digital Image
Resumo:
Digital Image
Resumo:
Project with MLA to implement recommendations from "Review of productivity decline in sown grass pasture".
Resumo:
Rapid change in climate is challenge for the adaptation of forest trees in the future. In wind pollinated tree species pollen mediated long distance gene flow may provide alleles that are (pre)adapted to a future climate. In order to examine the long distance pollen flow in Scots pine (Pinus sylvestris L.), we measured the amount and viability of airborne pollen and flowering phenology in central, northern, and northernmost Finland during four years. Viable airborne pollen grains were detected during female flowering and before local pollen shedding in all study sites. The situation when there was nonlocal pollen in the air lasted from one to four days depending on the year and study site. The amount of nonlocal airborne pollen varied also between years and study sites, the total amount of nonlocal viable pollen in the air was 2.3% from all detected viable pollen grains. The effect of pollen origin on seeds siring ability was studied with artificial pollination experiments. Pollen genotypes originating from southern Finland sired 76% and 48 % of the analysed seeds in competition studies where both pollen origin were introduced simultaneously into the female strobili. We examined the importance of arrival order of pollen grains in to the strobili in a study where pollen genotypes of different origin were introduced in two hours interval. Northern genotypes sired 76% of the analysed seeds when it was injected first, but in the "southern first" experiment both pollen types sired equal amount of seeds. The first pollen grain in the pollen chamber do not always fertilizes the ovum, instead there likely is more complex way of competition between pollen grains. To examine chemically mediated pollen-pollen interactions we conducted in vitro germination experiment where different pollen genotypes had chemical but not physical contact. Both positive and negative effects of interactions were found. We found highly negative effects in germinability of northern pollen grains when they were germinating with southern pollen, and increase in the germinability of southern pollen. There were no variation in the size of the dry pollen grains between pollen origins, and minor variation between different genotypes. After hydration and germination northern pollen grains were larger than southern pollen. Pollen genotypes having high hydration rates had low germinability and tube growth rate, however, germinated pollen grains were larger in size than nongerminated. This supports the suggestion that the early germination and growth of pollen tube is dependent on pollen storage materialsand less dependent on water intake and hydration. Long distance pollen movements and good competition ability of southern pollen makes gene flow possible, although rising temperature and timing of pollen movements may affect pollen competition and the amount of gene flow.
Resumo:
The first aim of this thesis was to produce data for evaluating, developing and recommending biologically and economically efficient energy and protein feeding strategies for growing and finishing dairy bulls offered grass silage-based diets. The second aim was to calculate the energy and protein supplies of the dairy bulls fed different grass silage-cereal-based diets and, based on this, to estimate the possible need to revise the current Finnish energy and protein recommendations for growing dairy bulls. The third aim was to demonstrate the phosphorus supply of dairy bulls fed grass silage-cereal-based diets with or without protein supplementation in relation to current feeding recommendations for phosphorus. The results indicate that protein supplement is not needed for finishing dairy bulls (live weight more than 250 kg) when they are fed good-quality grass silage (digestible organic matter more than 650 g/kg dry matter, restricted fermentation with low concentrations of fermentation acids and ammonia N) and grain-based concentrate with a moderate (300-700 g/kg dry matter) concentrate level. The results also suggest that with total mixed ration feeding it is possible to use rather high concentrate proportions (700 g/kg dry matter) in feeding dairy bulls. According to this study, barley fibre is a suitable energy supplement with good-quality silage for growing dairy bulls. The results suggest that 50% of barley grain can be replaced with barley fibre without affecting growth. Also oats is a suitable energy supplement for dairy bulls. However, as a consequence of decreased energy intake, the gain and feed conversion of the bulls were slightly reduced in this study when barley grain was replaced by oats in the diet. Ultimately, the rationality of the use of barley fibre and oats in the future will depend on the price in relation to other concentrates. During the feeding experiments the calculated supply of energy was 10% higher than in the Finnish feeding recommendations for the present growth rate. This indicates that there is a need to update the Finnish feeding recommendations for dairy-breed growing bulls, and further calculations are needed for the energy supply of growing dairy bulls. The calculated supply of AAT (amino acids absorbed from the small intestine) was 38% higher than in the Finnish feeding recommendations for the present growth. Possibly, the present AAT-PBV system is not an optimal protein evaluation system for growing dairy bulls more than 250 kg live weight. The calculations based on the feeding experiments and the Finnish feeding recommendations indicate that in most cases the dairy bulls (live weight more than 250 kg) received enough P from the basic grass silage cereal-based diets without additional mineral feeds. Therefore there is no need to add P in the form of mineral mixtures.