Lawn care is a constant process, and if we notice that something is not going on with it, then we cannot do without special knowledge. Lawns have a lot of enemies: weeds, moss, some insect pests. Moles, voles, even birds - rooks, sparrows. But still the biggest trouble is caused by diseases of the lawn or grasses that grow. The cause of the diseases are various types of fungi.
It is not always easy to diagnose a lawn - often the symptoms of one disease manifest themselves differently in different types of grass. They may be modified due to different environmental conditions. The matter is further complicated by the fact that on the lawn of different types of grass is possible the simultaneous course of various diseases. In addition, the symptoms are sometimes caused by other causes, such as drought, lack of or excess of certain nutrients, accidental splashes of garden or household chemicals, as well as urine of cats, dogs.
содерж to content ↑Weed control on the lawn
Weeds are not only harmful by spoiling the look of the lawn. They suppress the development of lawn grasses, taking away their water and nutrients. Rhizomes, leaves, even the seeds of some weeds produce toxins that inhibit the development of other plants. Such toxins exist in wheatgrass, creeper, field thistle, field bindweed.
Weeds are dangerous by the fact that they are often foci of various fungal diseases( large plantain, field mustard).Many of them become intermediate hosts for insect pests( wheat grass, dandelion, common ground spider, wood louse).Therefore, a very important aspect of lawn care is to prevent the appearance of weeds, and if they have already grown, then wage an effective fight.
Prevention measures: cleaning lawn grass seeds before sowing from weed seeds;cleaning the soil removed under the lawn from seeds, rhizomes of weeds( leaving the area under steam), weeding the areas adjacent to the lawn to prevent the growth of weeds there. When the grass lawn has become dense, powerful, he himself is able to resist clogging.
If weeds still appear on the lawn, then small areas can be weed manually. But the vast surface of the lawn has to be treated with selective herbicides that do not act on monocotyledonous plants( for example, systemic herbicides — 2.4 D( Dichlorophenoxyacetic acid), which destroy one-year, perennial dicotyledonous plants).Best results are obtained with the spring application of herbicides two weeks after the application of nitrogen fertilizers. Herbicide kills weeds, and fertilizer stimulates the growth of lawn grass.
When moss appears, which often happens when the soil is too acidic, wet, the lawn is harrowed in spring( or raked) or turf bayonet( pierced with forks), and iron sulfate is added - its amount is 10% of the dose of mineral fertilizer. In the summer you can spend a weak liming of the places where mosses appeared.
содерж to content ↑Lawn diseases - which are and how to fight themmoldIn the first case, small, gradually increasing spots( up to 30 cm in diameter) appear on the lawn, brown or orange at the edges, lighter in the center. Affected lawn plants usually look moist or slimy, and white or pink fungal mycelium glues dead leaves along the edges of the spots. The appearance of this disease is favored by wet weather, excess nitrogen in the soil, uncleaned or tightly compacted mowing.
In the case of snow mold, immediately after the snow has disappeared spots are white, due to the mycelium of the fungus, sometimes with brown-orange edges. These spots appear under the snow.
Various bluegrass species are particularly affected by these diseases. It is necessary to fight mainly with the help of proper agrotechnology, it is impossible to leave tall grass in winter, as the fungus is introduced in the winter into the dead plant tissues. Fungicides are also used, the most effective are systemic, but if the spots have already appeared, then the fungicides will not help here.
содерж to content ↑Dollar spot of lawn
The spores of the fungus Sclerotinia homoeocarpa cause a disease with the funny name “dollar spot” or a less harmonious synonym for “sclerotic”.It appears as white or straw rounded spots with a diameter of about 5 cm( silver dollar size).The development of lawn disease is favored by a lack of nutrients, especially nitrogen, as well as wet weather. Dollar spotting can occur throughout the summer, but most often it occurs at the end of the growing season. For the prevention of disease, liming acidic lawn soils, timely application of nitrogen, phosphate potassium fertilizers is recommended. If stains have already appeared, they should be removed along with a clod of earth. Particularly susceptible to fescue red, as well as bentholes, bluegrass.
содерж to content ↑Ophiobolus - lawn disease
The causative agent is the fungus Ophiobolus graminis( synonym - Gaeumanno-myces graminis).Round yellow or orange spots with a diameter of up to 1 m appear on the lawn. The center of these spots is gray, because the grass dies there, and weeds grow in its place or there remain disease-resistant grasses. This disease is especially susceptible to the field shoots, bluegrass annual. The development of the opiobolus is favored by wet weather, an excessively alkaline lawn soil. Fungicides, as a means of struggle, are not effective, so it is better to try to prevent its development - avoid over-wetting, use sulfur or ammonium sulfate on excessively alkaline soils to increase acidity.
содерж to content ↑Red mold or rust on the lawn
The causative agent is the fungus Corticium fuciforme( synonym. Laetisana fuciformls).This disease is called “gelatinous red mold”, “autumn rust”, “leaf rust”.Spots up to 35 cm in diameter appear on the lawn. This disease can appear throughout the summer, but most often at the end of the growing season. She provokes a combination of hot weather with a lack of nutrients, especially nitrogen. Rusty red fescue, pasture ryegrass suffer from leaf rust. The use of systemic or contact fungicides, the application of nitrogen fertilizers helps to control the situation, but you have to be careful with this, since an excess of nitrogen contributes to the development of other diseases of the lawn, for example, spotted fusarium.
содерж to contents ↑Tifulez or gray snow mold
Typhula idahoensis mushroom is the causative agent of “gray snow mold,” typhulosis. It resembles pink snow mold, appears when snow melts are delayed, as well as in too damp shaded areas. Struck herbage covered with grayish-pink mold. Control measures include treating the lawn with fungicides or rakes, applying phosphate fertilizers.
содерж to content ↑Powdery mildew and mucous mold
Dirty, or mucous mold( Didymium crustaceum) and powdery mildew( Erysiphe graminis) are not as dangerous as the diseases already mentioned. The main measure against them is regular mowing. Dirty mold can be simply washed off with a strong jet of water, and against powdery mildew, apply a spraying of copper-soap mixture( 20 g of copper sulfate + 200 g of liquid soap + 10 l of water).
There are several types of fungal diseases that affect lawn grass seeds before or immediately after germination:
- Mushroom Rhizoctonia solani - is the causative agent of brown spot, affects the bases of sockets, root plant necks. The disease manifests itself as dark brown or scarlet spots on young shoots. There are other similar mushrooms, for example, Pitium, Drehslera. To avoid the death of seedlings, a good preplant preparation of the soil is necessary, the correct sowing density, suitable dates are not too early in spring or not too late in autumn, because dampness contributes to the development of these diseases. For confidence, you can conduct pre-sowing seed treatment with a special formalin.
- "Witch rings" - some species of cap mushrooms tend to grow chains, sometimes it looks like rings. It can be different types of mushrooms, but the most dangerous for lawns is the mushroom Marasmius oreades. Its rings can exist for hundreds of years, expanding every year by 30 cm, that is, the spot diameter is constantly increasing. These mushrooms form a large mass of mycelium, deprive the grass of food, moisture, but, nevertheless, their fruit bodies themselves become organic fertilizer. Therefore, on the outer edge of the witch's ring, withered shoots are always visible, and inside it - bright fresh greens of newly grown, fertilized grass. Caring for a lawn when detecting “witch rings” is as follows: remove turf in the affected areas of the lawn, replacing the soil with a healthy one, or pickle the soil with formalin.
