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1.
J.D. Quinlan A.P. Preston 《The Journal of Horticultural Science and Biotechnology》2013,88(4):525-534
Fruit set was increased by removing all shoots 5 days after full bloom and at weekly intervals thereafter from trees of Sunset and Laxton’s Fortune, but removing shoots from Fortune trees 25 days after full bloom produced no beneficial effect on fruit retention. All treatments resulted in a heavier rate of fruit shedding during the ‘June drop’ period than occurred from control trees, and at harvest the trees without shoots had fewer fruits, and lower yields, than the controls. In a comparison of shoot removal and shoot tip removal starting 15 days after full bloom on Fortune trees, both treatments improved set, but whereas shoot removal caused a heavier ‘June drop’ compared with untreated trees, shoot tip removal increased the number of fruits retained to harvest and produced a yield increase. The difference between the two treatments in their influence on fruit retention, during and after the ‘June drop’, is accounted for by the beneficial effect of a relatively small number of leaves on each tipped shoot. Studies on the pattern of distribution of photosynthates, using 14CO2 and autoradiography, produced results supporting the concept of competition between fruits and shoots and also showed changes in the pattern of assimilate movement brought about by shoot tip removal. It is concluded that competition between fruits and shoots, occurring during blossoming and the following 2–3 weeks, may limit fruit set, but the presence of shoot leaves is beneficial to fruit retention in the later part of the season, particularly during the ‘June drop’ period. 相似文献
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The prevalence of Mycoplasma ovipneumoniae and Mycoplasma arginini in the respiratory tract of sheep
M.R. Alley B.V.Sc. Janet R. Quinlan B.Sc. J.K. Clarke B.Sc. Ph.D. 《New Zealand veterinary journal》2013,61(7):137-141
Abstract Extract In an initial study of mycoplasmas of the respiratory tract of New Zealand sheep a number of strains of mycoplasma were recovered and identified as either M. ovipneumoniae or M. arginini (Clarke et al., 1974). Investigations in Australia have produced evidence that M. ovipneumoniae is associated with a proliferative interstitial pneumonia in Queensland sheep (Sullivan et al., 1973) and for this reason the present survey was undertaken to investigate the prevalence of mycoplasmas in the respiratory tract of sheepin New Zealand. 相似文献
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T. Quinlan B.V.Sc. D.V.C.S. B.E. Goulden B.V.Sc. Ph.D. M.R.C.V.S. M.A.C.V.Sc. A.S. Davies B.V.Sc. Ph.D. 《New Zealand veterinary journal》2013,61(7):145-147
One problem in the diagnosis of subclinical roarers is that abnormal auditory signals occur only during a fast gait, and these fade quickly. This paper offers a novel technique to assist this problem. Sound recordings were obtained from five horses following exercise; two roarers, two non-roarers, and one suspected roarer. These signals were converted into spectrograms by Rayspan processing. All frequencies in the 0 to 2.25 kHz range during both inspiration and expiration, as well as occasional noises in the 2–4 kHz band, characterised roarers. Signals from non-roarers consisted of frequencies in the 0 to 2 kHz range with long quiet periods, especially during expiration. An explanation for these phenomena is offered, and supported by diagrammatic cross-sections of equine upper-respiratory tracts. It is suggested that the present technique could assist in the diagnosis of sub- clinical roarers, estimated to be between 20 and 40% of the competitive horse population. 相似文献
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A three-dimensional circulation model was used in conjunction with larval fish vertical behaviour models to study the interaction between larval vertical distribution, advection and the outcome of larval transport along the central portion of the east coast of the United States. The circulation model was forced by tides, a northern boundary inflow, and winds. Vertical behaviour models were developed for Atlantic menhaden ( Brevoortia tyrannus ) and spot ( Leiostomus xanthurus ). The purpose of this modelling effort was to investigate the transport pathways of Atlantic menhaden and spot larvae from offshore spawning grounds to estuarine nursery habitats. The coupled circulation and behavioural model demonstrated the importance of along-shelf transport in what is generally thought to be a 'cross-shelf' problem. Cross-shelf transport was associated with bathymetric features, such as shoals. Both physical (e.g. wind) and biological (e.g. changes in larval behaviour) events were responsible for many of the observed patterns in larval transport. Overall, larval transport was determined by circulation but was modified by larval vertical distributions. 相似文献
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J. S. Kamboj G. Browning J. D. Quinlan P. S. Blake D. A. Baker 《The Journal of Horticultural Science and Biotechnology》2013,88(5):773-780
SummaryThe polar transport of [3H]-indole-3-acetic acid in apical shoot segments of clonal apple rootstocks (M.27, M.9, M.26, MM.111 and MM.104) was investigated in the UK using a donor-receptor system. The month in which the experiment was undertaken had a significant influence on the uptake and transport of [3H]-indole-3-acetic acid activity; uptake and transport were greater in June and July (faster extension growth period) than in August (slower extension growth period). Shoot segments from dwarfing rootstocks (M.27 and M.9) showed smaller uptake and less transport of [3H]-indole-3-acetic acid than those from invigorating rootstocks (MM.111 and MM.104). [3H]-indole-3-acetic acid was transported to the agar receptors through shoot segments from all the rootstocks in June and July; those from dwarfing rootstocks showing lower levels of transport than those from invigorating ones. However, in August, [3H]-indole-3-acetic acid activity from the agar receptors was detected only from shoot segments of invigorating rootstocks, which continued to produce extension growth slowly, when dwarfing rootstocks had already ceased shoot extension growth. These results are discussed with reference to the effects of apple rootstocks on the size of scions. 相似文献
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Low doses of deltamethrin cause prolonged knockdown of the tsetse fly Glossina morsitans morsitans. Fifty per cent of female flies, treated with the LD15-(48 h) of deltamethrin, failed to regain their capacity for normal flight for 30 h, compared with 6 h for bioresmethrin and 4 h for permethtin at the equivalent dose. Recovery after exposure to tetramethrin occurred within 1 h. The knockdown effect of deltamethrin on males was even more pronounced although, with both sexes, the onset of the effect was delayed for about 3 h. It is suggested that this prolonged knockdown effect of deltamethrin, at extremely low application rates, may make a significant contribution to the effectiveness of the compound against the tsetse fly. 相似文献
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B.E. Goulden B.V.Sc. Ph.D. M.A.C.V.Sc. M.R.C.V.S. G.R.G. Barnes B.Sc. T.J. Quinlan B.V.Sc. D.V.C.S. 《New Zealand veterinary journal》2013,61(7):148-150
Abstract Extract The abnormally long occlusion of the laryngeal aditus by continued action of the intrinsic laryngeal muscles (laryngospasm) has been recorded in many experimental and domestic animals and in man. Most reports on laryngospasm have been related to its occurrence under general anaesthesia where it has been foundin all the domestic species (Lumb, 1963; Westhues and Fritsch, 1965; Hall, 1966) but is most commonly encountered in the cat (Rex, 1969). 相似文献
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Abstract The mountain catchments above 2 750 m a.s.l. in eastern Lesotho are a proclaimed Managed Resource Area (MRA) as a result of official concern about degradation of the grasslands of the alpine belt, and of recent parastatal interventions in the local livestock economy. However, the demarcation of the MRA may be inappropriate because it ignores recent changes in the transhumance system which threatens to cause greater degradation of the grasslands in the subalpine belt, particularly in the lower subalpine zone. In response to a variety of ecological and social factors, Basotho have modified the transhumance system by establishing winter grazing posts in this zone which lies between the summer grazing post areas in the subalpine zone and the alpine belt and the villages. The former areas are now used more intensively than the latter areas, thereby increasing the potential for greater degradation in the lower subalpine than in the upper subalpine zone and in the alpine belt. It is argued that the conservationist perspective, by which the MRA was demarcated needs to be broadened to include these lower valleys in view of these ecological dynamics. 相似文献