Diseases of sunflower, as well as pests, cause considerable damage to the economy. As a result of diseases of sunflower, the yield is reduced by several times or the whole sowing may perish. Therefore, knowledge that will help to distinguish between the main diseases of the sunflower and know the measures to combat them is important when growing sunflowers.
- How to cure a sunflower from gray rot
- White Rot Treatment in Sunflower
- Ways to treat broomrape on a sunflower
- Downy mildew
- How to cure a sunflower from fomoz
- Fomopsis sunflower
- Bacteriosis wilt
- Treatment of septoria
- Black spots on sunflower
- Sunflower altenaria
- Dry rot of baskets
How to cure a sunflower from gray rot
Gray rot stem - this is when the sunflower stalk rots completely from the bottom to the top. The disease is possible at any stage of development - from freshly sprouting to ripe sunflower. Humidity contributes to the development of the disease, as the disease is fungal, and almost all fungi (but there are exceptions) love moisture.With gray rot, the stem becomes covered with a yellowish-gray bloom, which eventually becomes dark brown, and then sclerotia (dense areas) of black color appear on the surface. In this case, the lowermost leaves dry on the stem, and the upper ones begin to wilt.
The defeat of mycosis in the harvest stage passes to the cap and is characterized by oily secretions and dark gray bloom on the basket, and after 8-12 days sclerotia are found in the seeds. Control measures against rotting: maintaining crop rotation and preventing damage by dressing before planting seeds, for example, with TMTD in 80% concentration. In addition, prophylactic treatment of crops after germination and before maturity is carried out with the following compounds: Vesuvius, Glyphos super, Dominator, Clinique Duo, Chistopol, etc.
White Rot Treatment in Sunflower
Sunflower is sick of it at any stage of growth. The disease is characterized by the formation of a cotton-like or flocculent milky-white plaque in the lower part of the stem and roots, the affected areas then become brown-brown in color.
The stalk at the root softens, breaks, the foliage fades, the sunflower dies.But it can affect only the stem without roots - in this case the brown rot is noted in the middle part of the stem, which then cracks in the middle. The most common form of white rot is when the disease develops in the ripening phase of the sunflower. Then brown patches are formed on the basket, covered with whitish cotton-like bloom with the formation of sclerotia. And at a later stage, the seeds fall out and instead of a basket there are putrid formations in the form of cords.
The treatment is not carried out, the affected plants are destroyed. And the most effective measure to combat white rot - its prevention. For this, all agrotechnical measures for growing sunflower, seed dressing before sowing and spraying as the plants grow with the same compositions as for gray rot are observed.
Ways to treat broomrape on a sunflower
Sunflower contagion (top) is a weed infestation of crops, as a result of which parasites-weeds destroy sunflower, taking away nutrients and moisture from it.
This disease of sunflowers, as broomrape, is characterized by the germination of weedy crops in sunflower roots and the appearance of haustoria - processes in the form of threads,which suck out of the plant and consume instead its intended mineral and organic matter. Prevention and treatment of broomrape - planting crops next to the sunflower that are not sensitive to grass-parasite - corn, soybeans, flax, and sowing sunflower varieties that are resistant to the parasitic weed. This helps to avoid diseases of the roots of sunflower.
Also an effective measure against broomrape is the flyom of a phytomiza, the larvae of which eat the broomrape seeds and which is specifically released at the flowering stage of the weed parasite.
Downy mildew
Sunflower mildew, the causative agent of which is a fungus, does not in fact often infect a plant. More common is powdery powdery mildew of sunflower, which is also provoked by fungi. The disease occurs in both the early and late phases of sunflower development. In the first case, this is a period of 2-4 pairs of development of true leaves of the plant, and the signs will be as follows: a stalk thickened along the entire length with corrugated leaves, on the underside of which is a milky white scurf, and on the top there may be a pale greenish scurf.
Young plants either die, or form underdeveloped seedless baskets. At the late stage there are whitish spots on the foliage below and brown-brown on top, the stalk on scrapping inside is beige-brownish (instead of white), with no visible thickening of the stalk and lesions of the baskets.
There is no treatment as such. If the sunflower does not fully recover, then the agrofungicides - Alpha standard, Amistar-extra, Dezal, Derozal, Carbezim, Ultrasil-duo, Efatol, used for powdery mildew - will only hinder the development of mycosis. Therefore, it is desirable to carry out preventive measures when planting seeds (fungal treatment) and to use sunflower varieties with increased resistance to the causative agent of downy mildew.
How to cure a sunflower from fomoz
Sunflower fomoz is also a mycotic disease, characterized by the appearance of red-brown and dark-brown areas with yellowish edging on the foliage.This usually occurs at the stage of 3-5 pairs of true leaves, but the plant can get sick in any phase of growth.
Subsequently, the whole leaf is affected, it fades and sags, and the defeat goes to the stem. At first, parts of the stalk are affected in the places where the leaves are attached, and then the spots expand, merge, and the whole trunk becomes brown-brown or even black. Then the disease moves to the basket, affecting its tissues and seeds.
Anti-fomoz measures - spraying with effective fungicides during the growing season (Impact-K, Derozal, etc.), strict adherence to crop rotation and agrotechnical measures, taking into account previous crops.
Fomopsis sunflower
Sunflower Fomopsis or Gray Spotting - A fungal infection of leaves, stems, baskets and seeds of plants. The disease is characterized by brown-silvery putrefactive spots on the foliage and stalks of the sunflower. After a while, the leaves of the plants dry up, wilt and twist, and the stalks in the places of rotting break.With the defeat of the baskets, the seeds are gray-brown and half-empty.
The fight against fomopsis - compliance with the rules of crop rotation and seed dressing with fungicides before sowing and processing of sunflower on the field in the vegetation stage (the preparations are the same as with fomoz).
Bacteriosis wilt
This is a bacterial disease of sunflower that can develop at any stage of the growing season, and depending on the growth phase, various signs of damage will appear. At the stage of 3-5 pairs of leaves, the stem is partially shriveled, twisted and assumes a characteristic knee-curved shape, and the leaves turn brown, dry out and curl. The lesion in the later phase is characterized by a dried brown top of the stem - from the basket and 10-12 cm down, and its root part cracks a little later, as it becomes hollow. The stem core is colored sandy brown. The basket itself shrinks, wilts, while the foliage remains normal, green and without signs of wilting.
Measures to combat bacteriosis wilt are as follows: frequent examinations of crops and at the first signs of the affected plants are uprooted and burned.
Treatment of septoria
Septoria or brown spotted sunflower is a mycosis that can develop at different stages of growth. With the defeat of this fungus is characterized by dirty-yellow, and then brown-brown spots on the foliage, surrounded by whitish-green edging. Subsequently, the affected leaves are covered with black dots and holes - dried-up areas partially fall out.
The fight against septoria is the prevention of the disease, namely spraying of sunflower during the growing season with agrofungicides (Acanto plus, etc.), autumn harvesting of residues in the fields and respect for crop rotation.
Black spots on sunflower
Black spot or embelisia - a fungal infection of foliage, stem, and sometimes sunflower baskets. More often young plants are affected in the phase of 2-5 leaves, but the already ripening sunflowers are also sick. The disease is contagious, and when it is detected in other countries, quarantine is introduced.Signs of embelisia: black and / or dark brown round or elliptical spots or black small strokes (stripes), first protruding along the edges of the leaves and going to the middle, and necrotic cracks form on the trunk on the spots.
The fight against black spot is the treatment of seeds before sowing, compliance with agricultural practices and crop rotation of sunflower.
Sunflower altenaria
Fungal disease of sunflower, characterized by damage to the foliage, stems, baskets. On all parts of the sunflower appear brown-graphite with a greenish blotch stain, different in size. Further, the spotting becomes light green with a gray-black or graphite coating. Fight against altenariosis - treatment with agrofungicides in the growth phase of sunflower crops and respect for crop rotation.
Dry rot of baskets
This is a fungal disease of sunflower baskets. There are two types of dry rot - pink and brown, respectively, by the color of the mold. Defeat and brown and pink rot occurs, as a rule, at the very beginning or middle of ripening sunflower. In the case of brown rot, baskets softened from below appear on the basket, but brown areas dense from above. Seeds with underdeveloped, sticky and sticky, can partially fall out of the basket. With pink rot, everything is the same, only the lesions start from the seeds themselves and go inside the basket, and the color of the spots is whitish at first and then pink.
Measures to combat dry rot: strict observance of the rules of crop rotation, seed dressing, spraying the field with fungicides as crops grow.
Affordable protection of sunflower from diseases should be carried out necessarily, and most importantly, in time, it is both easier and cheaper for any farm.