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A plant that completes its life cycle within one year. This means that it germinates, grows and develops, flowers and then produces seeds which then go on to germinate in the subsequent year. Examples of annual plants include: • Ageratum houstonianum • African Marigold (Tagetes erecta) • French Marigold (Tagetes patula) • Petunia • Nicotiana langsdorfii • Hare's tail grass (Lagurus ovatus) • Love in a Mist (Nigella damascena) • Annual Phlox (Phlox drummondii) • Some plants are short lived perennials, but may be grown and treated as annual, e.g. Snapdragon (Antirrhinum majus), Nemesia.

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Organisms having a disliking for other organisms, often leading to reduced activity of one or more of the organisms. There is often routine antagonism between many soil micro-organisms which often keeps them in check, preventing one organism from gaining a significant advantage over others. If this did not occur then this could lead to an imbalance within the soil, having a consequential negative impact on the health of a grass sward.

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An organism, especially bacteria or fungi, which has a detrimental effect on another organism. Sand rootzones often have much less abundance and diversity of soil micro-organisms and this can lead to increased likelihood of infection and damage from turf diseases and pests (for example plant parasitic nematodes). In many constructed sports turf rootzones, there is an unnatural imbalance between the more desirable soil micro-organisms and those which can harm turf, and this typically results in the need for increased resource inputs to maintain these surface to the desired, often very high, standard.

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The opening (splitting) of the anther due to its drying out and the release of pollen from the locule cavities in the anther. Temperature and light influence anthesis, with May through to mid-July typically being an optimum time for pollen production in grasses (with hay fever being a negative consequence of this for some humans), whilst relative humidity will typically have a more limiting effect on the process, having a dampening effect.

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Pigment within grass leaves which can be produced during times of plant stress. Different colourations can occur, with a blue, purplish or reddish tinge being common. A deficiency of phosphorus commonly leads to a purple tinge to a leaf. High, low or changing levels of light, especially during colder periods leading into the autumn, can all contribute to the production of anthocyanins. The use of supplementary lighting could influence, by increasing, the anthocyanin content within grass leaves, giving an inference of a nutrient deficiency when one does not exist.

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Stresses which are directly caused by the actions of humans, rather than by natural non-organic (abiotic stressor) or biological means (biotic stressor). This type of stressor might, however, typically be included within that of abiotic stressor. Examples include: • Soil compaction especially from machinery use or players. • Misapplication of chemicals, especially pesticides, reducing plant or soil health. • Climate change, which is having a major impact on global environments, but also influences extremes of weather, such as flooding, droughts and very high temperatures (all abiotic stress

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A material which is usually sprayed onto a plant (especially ornamental plants) to reduce its rate of transpiration. An example is Wiltpruf S600 (manufactured by Vitax and which contains the active ingredient di-1-p-menthene) which produces a thin and transparent layer on the epidermis / outer tissues helping to reduce the effects of drought and drying conditions.

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Plural of Ascus.

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A name previously used to mean Ascomycota.

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A division, or phylum, of the Fungi Kingdom. Spores (called ascospores) are ejected from the inside of small fruiting containers called asci. There are approximately 5,600 species of Ascomycota in the British Isles.