How to Cure Plant Chlorosis
Plant chlorosis (from the Greek. Chloros – pale green) is a disease in which the formation of chlorophyll in the leaves is impaired and photosynthesis activity is reduced. The characteristic signs of chlorosis are premature yellowing and falling of leaves, small leaves, drying out of the tops of shoots, dying off of active roots and the like.
The causes of plant chlorosis are various. There is infectious plant chlorosis, which is caused by microorganisms (viruses, mycoplasmas, bacteria, fungi). The carriers of its pathogens are often planted pests (thrips, aphids, cicadas). For example, mycoplasmas cause characteristic diseases – jaundice.
As the infection spreads, the blood vessels of the plant become discolored, the leaves turn yellow and become chlorotic. Chlorosis of plants is also caused by many fungal plant pathogens of the genera Fusarium, Verticillium, and Cladosporium. Chlorotic spots on the leaves of many plants appear when they are affected by alternations, peronosporosis, and other diseases.
Non-infectious or functional, plant chlorosis develops under adverse soil and climatic conditions, as well as violations of crop cultivation technology. Plant chlorosis is often manifested with a lack of nutrients – nitrogen, proteins, as well as with increased soil acidity when minerals become inaccessible to the roots. Non-infectious chlorosis can also be caused by poor drainage of the soil, which causes over moistening of the roots, damage to the roots or too small space for them.
The main nutrients can be divided into two groups: macrocells – nitrogen (N), potassium (K), calcium (Ca), phosphorus (P), magnesium (Mg) and microelements – iron (Fe), sulfur (S), copper ( Cu), boron (B), zinc (Zn), manganese (Mn), molybdenum (Mo), chlorine (Cl). With nitrogen deficiency, the symptoms of plant starvation are manifested: growth is slowed down, the stems are thin, fibrous and solid. Large yellow-green spots appear on the leaves. As starvation intensifies, root growth stops, they turn brown and die. In the case of acute starvation, the entire chlorophyll of the leaves breaks up, and they turn yellow.
To eliminate nitrogen starvation, fertilize with urea, ammonium nitrate, plants are sprayed with urea or use a fertilizer with a high nitrogen content – master. Non-infectious plant chlorosis can most often be caused by a deficiency in the soil of minerals such as iron, magnesium or manganese.
Signs of glandular chlorosis of plants: young leaves first acquire a light yellow color between the veins, later the entire leaf turns yellow. With a severe lack of iron, the lemon-yellow color turns into white-yellow and the leaves die off. Symptoms appear more on alkaline and highly calcareous soils.
Magnesium chlorosis of plants: yellowing starts from the edges of the leaf, the green triangle remains only at its base. Chlorosis of the leaf blade, sometimes in the form of solid spots, begins on the periphery of the leaf. The leaves become brittle, sometimes twist up, later they fall, the plant weakens. Chlorotic tissue turns brown and dies. Thick veins remain green. Starvation is noted on acidic soils. Manganese deficiency:
chlorosis develops first on young leaves between the veins, and then on old ones. Veins retain a green color even with very severe starvation. Chlorotic tissue turns brown or becomes transparent, gradually the tissue is necrotic. Necrosis is usually single, local. Copper deficiency occurs primarily on young leaves, buds, and shoots. Old leaves develop chlorosis, growing leaves fall off, leaves are pale green in color, dry at the tips. Sometimes hereditary plant chlorosis is isolated, which occurs as a mutation and is inherited. This property is used in the selection of ornamental plants for breeding variegated forms.
- In order to prevent plant chlorosis, organic and mineral fertilizers are used, deoxidation of carbonate soils or liming of acidic soils, mulching and sowing of row-spacings, destroy pests that transmit the infection.
- With infectious chlorosis, preventive and protective measures are carried out aimed at eliminating the cause – the causative agent of the disease. Plants affected by viral and mycoplasma infection destroy.
- In the treatment of non-infectious plant chlorosis, the missing nutrients are introduced into the soil near the active zone of the root system, and foliar top dressing is also used.
- For plant nutrition, both complex preparations and preparations with specific individual trace elements are produced. For example, the drug Brexil (Brexil), in which trace elements are in the form of an LPCA complex (lignin polycarboxylic acid), is used for foliar feeding. And for watering use chelate forms of the drug. Brexil combi is recommended for crops grown on alkaline soils, Brexit mix – for plants growing on organic or acidic soils, multi Brexil – for crops that suffer from a general nutrient deficiency and especially need magnesium. Separately, Brexil Fe, Brexil Mg, Brexil Mn, Brexil Zn, Brexil Ca.
The use of the drug fulvital +, which contains biologically active low molecular weight fulvic acids and trace elements – Fe, Zn, Mn, Mg, Cu, S, soluble in both acidic and alkaline media, gives good results in the fight against plant chlorosis. The drug is used to treat seeds and vegetative plants (with irrigation water).
The use of humic preparations and complex fertilizers provides vegetable crops with macro- and microelements, preventing chloroses, which slow down the growth and development of plants. It should be noted that in the treatment of chlorosis, shifts do not appear immediately.
Chlorous leaves can no longer return to their previous vital activity, but the appearance of green healthy, young leaves is the first sign of an improvement in the condition of the plant. If the young leaves also turn out to be chlorous, then the plants will need not only top dressing but also watering under the root.