subject: The Disorder Of Plants [print this page] The lack of potassium is a physiological disorder of plants, most common on light soils, chalky or sandy peat, low in clay . Also occurs in heavy clay soils of poor structure .
Plants need the ion potassium (K + ) for the synthesis of proteins and the opening and closing of stomata , which is regulated by proton pump to maintain the turgidity of the cells that surround them. A deficiency of potassium ions can weaken the ability of plants to maintain these physiological mechanisms.
Deficiency, most often affects the fruits and vegetables , especially potatoes , the tomato , the apples , the currants and Ribes uva-crispa . Typical symptoms are drying and curling of leaves and yellowing of the leaf veins. Purple spots may also appear in the bottom of the leaves .
Deficient plants may be more susceptible to damage from the frost white and diseases and deficiency symptoms can often be confused with drying due to wind or drought .
Prevention and treatment can be done by providing short-term manure Comfrey homemade, of algae , the compost of ferns or other organic fertilizer rich in potassium. In the long term soil structure should be improved by adding large quantities of well rotted compost or manure . The ash timber, high potassium content, they must first be composted as it is a highly soluble form.
For other uses of this term, see dehiscence (medicine) .
In botany , the term dehiscence means the spontaneous opening of a plant structure, once arrival maturity to release its contents.
Referred to many types of fruit , means the time at which they are opened to release the seeds and disperse , so we talk about loculicidal dehiscence when the fruit is opened by the midrib of the carpels .
Referring to anthers , is when they are opened, releasing the pollen .
In the lower floors, is also called the opening dehiscence of sporangia , releasing sexual or asexual spores.
Dehiscence is the last function of the anther , which causes the release of the grains of pollen . This process is exactly coordinadao with pollen differentiation, floral development and openness.
The wall of the anther splits longitudinally, producing as an indentation between the locules of each theca .
The stomium is the region where the anther dehiscence occurs. Necrptica degeneration of cells of the stomium and the septum is part of the programmed cycle of development and cell death. The expansion of the layers of endoteciales and lignification of cell walls are essential to endoteciales dehiscence.
Depending on the shape of opening of the anther can be classified as:
Longitudinal dehiscence: When the anther opens lengthwise, ie from top to bottom or vice versa.
Dehiscence transverse: When the anther is opened transversely.
Dehiscence apical: one in which it opens a pore apical leaves through which pollen.
According to the direction in which the filaments make the process of dehiscence, can be:
Dehiscence introsa: That which occurs towards the center of the flower , this facilitates self-pollination .
Dehiscence extrorsa: one that occurs out of the flower, which requires a great deal to the pollination cross.
