Wilt (plant)

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Coneflower flowers withered in the heat of the sun

Wilt refers to the flaccid state of plants , which occurs due to insufficient water supply, but also due to a lack of potassium or pathogens. Wilt manifests itself in what is known as wilting: flabby leaves that hang down. Wilt occurs when plants are no longer able to maintain turgor through osmotic water uptake.

Cellular processes

During wilting, the affected cells contract due to the loss of water. A plasmolysis does not occur in land plants. With greater water loss , the cell wall is pulled inwards and can also wrinkle (cytorrhysis). The individual cell compartments shrink and the substances dissolved in the cell are concentrated. This hinders many metabolic processes, especially photosynthesis and mitochondrial respiration . As the loss of water progresses, the vacuole fragments into small partial vacuoles , the thylakoids of the chloroplasts and the cristae of the mitochondria initially swell and are then broken down. In the early stages of wilting, the processes can still be reversed, but cell death ( necrosis ) occurs after the membranes break down .

trigger

In nature, the wilting of plants is largely due to a lack of water availability. On the one hand, the distribution of the annual rainfall is independent of the need for plants, on the other hand, the water holding power of the various arable soils is very different. The water storage power or the rain storage capacity of a soil is called field capacity . This depends on the type of soil , the soil structure and humus content as well as the turbation . The factors retained water , capillary water , soil water potential and hygroscopicity of the soil are critical to the water availability of the plants. The permanent wilting point describes the suction tension from which plants cannot take water from the soil and wither.

For continuous frost with appropriate frost depth it comes to Frosttrocknis a particular kind of withering.

Root corrosion can also lead to a lack of water and thus to wilting. The causes are, for example, white grubs and the mole cricket .

In addition to the lack of water, plant diseases can also lead to wilting. Examples are the Verticillium wilt and Fusarium wilt caused by fungi , or the bacterial wilt caused by Xanthomonas stewartii .

Individual evidence

  1. ↑ a b Schück, Schuck, Stimm: Lexicon of tree and shrub species . Nikol, Hamburg 2002, p. 567. ISBN 3-933203-53-8
  2. ↑ Walter Larcher: Ecophysiology of plants . 5th edition, Ulmer, Stuttgart 1994, ISBN 3-8252-8074-8 , pp. 179 f., 306.

literature

  • Ernst Klapp ; Textbook on arable and crop cultivation, Paul Parey publishing house, Berlin and Hamburg 1958.
  • Manfred G. Raupp: What the grandfather already knew - thoughts on the development of agriculture in Staffort; Stutensee-Staffort 2005.