Dodder (Cuscuta) is a dangerous weed that can cause tremendous damage to cultivated plants growing in the garden. If earlier only one species of this weed was included in the Povilikov family, today breeders have about 200 varieties of dodders. She prefers to coexist next to crops of fodder, melons and vegetables. Among other things, the weed is a threat to potatoes, flax, ornamental shrubs and trees. Dodder has an adverse effect on the development of plants and slows down the course of metabolic processes inside tissues, as a result of which the plant loses strength and dies.
Dodder is a unique weed that does not have leaves and roots and is a long elongated stem that wraps around the entire plant. The color of the stems can be yellow, red or light green. With the help of peculiar suction cups, they attach to the vegetative parts of the plant, infect tissues and suck out juices. Diseased plants almost always die. According to experts in botanical research, this weed can determine the location of its prey by smell. Small dodder flowers form spherical inflorescences of white, pink or green color. After ripening, the weed fruit looks like a rough seed pod, capable of maintaining germination properties for a long time. Dodder seeds outwardly almost indistinguishable from the seeds of its occupied cultivated plants. For this reason, there is a huge risk of sowing a quarantine pest with other flowers.
Dodder is characterized by rapid growth and can cover large areas. For example, one weed seed is enough to form a lesion with an area of more than 6 square meters. Stems with increased turgor pressure in the tissues retain their stability for a long time in case of damage and do not dry out. Forage grasses in which weed residues are present quickly rot and are unsuitable for animals. Dodder is considered a carrier of viral diseases. It contains toxic alkaloids that cause massive cases of cattle poisoning.
Preventive measures play an important role in the fight against this weed. These include pre-treatment of seeds prior to planting, as there is a risk of pest contamination of seeds. If you manage to find traces of weed in the garden, then try not to use the seeds collected near this place. Such sowing material can negatively affect the harvest, so the best option would be to purchase high-quality seeds in stores selling goods for summer cottages and gardens.
However, the main reason for the infection of plants is the diseased soil, in which the seeds of this parasite gradually accumulate. To get rid of them, it is necessary to regularly plow a piece of land to the depth of a shovel handle to accelerate seed germination. After the first shoots appear, the weed is easy to find and destroy. At this point, you can plant wheat or oats so that the soil is properly cleaned. On such crops, dodder will not be able to parasitize. Another way to stimulate weed growth is to water the soil abundantly in spring or autumn. Dodder needs food and is not adapted to develop separately from other plants. When there is no suitable nutrient nearby, the weed dies over time.
If the dodder has filled a fairly large area of the site, then all the plants will have to be mowed and burned. Only in this way can the garden be protected from further occupation by a pest. Don't wait for the weed to bloom. In the west, special gas flamethrowers are used to combat the dodder for infected vineyards and fields. In our area, this technique is rarely used for its own reasons.
It is not recommended to apply fresh manure as fertilizer to the soil; it is better to use humus. When composting manure, weed seeds die.
If all the measures related to preventive and agrotechnical measures did not lead to the desired result, it is worth trying to remove the dodder with pesticides. The area, cleared of weed shoots, is watered with a solution of ammonium nitrate and ammonium sulfate with the addition of ethylhexyl salts. However, keep in mind the fact that other plants may die along with the pest. Unfortunately, it is impossible to cope with it with other fungicides, for example, copper sulfate, kerosene or sulfuric acid.
Herbicides can only resist young dodders. After flowering, the weed increases its resistance to chemicals. An important point is the fact that the treatment with herbicidal solutions must be carried out after watering or rain. This will speed up the absorption of toxins.
Reitar, Zenkor Liquid or Gezagard are often used as drugs that effectively fight against dodder parasitizing on fruit and vegetable crops. Carrots are processed using Reitar and Stompa, taken in equal proportions. Foreign-made preparations, for example, Titus and Targa, are considered an excellent remedy for weeds of this type. In any case, for the complete recovery of plants and the release of the site from the pest, it is best to look for an integrated approach to solving this problem, while simultaneously applying chemical and agrotechnical measures.
Traditional methods and recipes will not be able to cope with dodder, so you should not waste time, but use more effective means of struggle.
One of the most common weed species in our latitudes is considered to be:
LADY-WEED-PARASITE! HOW TO FIGHT THIS QUARANTINE PLANT.
Ministry of Education and Science of the Russian Federation
Municipal educational institution
secondary school №16
Parasites. Are they needed on Earth?
Completed: student of grade 5b
Supervisor: teacher of chemistry and biology
2.5 Disease-causing bacteria 10
2.6 Biological pest control 11
The purpose of this work is to collect as much information as possible about parasites (concept, methods of nutrition, classification), to find out what role parasites play in nature: positive or negative? Find the answer to the question "Are parasites needed on Earth?"
Recently, the topic has become very relevant: "What role do parasites play in nature: positive or negative?"
2.1 Parasites concept.
Parasites (from the Greek parásitos - parasite, parasite) are organisms that feed on other organisms (called hosts) and, for the most part, harm them. Parasites are subdivided into: zooparasites (protozoa, helminths, arachnids, insects, etc.) and phytoparasites (bacteria, fungi, some higher plants, etc.). Viruses are also referred to as parasites.
Parasites belong to different taxonomic groups of animals (excluding echinoderms, most chordates) and plants (they are absent only among bryophytes, ferns, and gymnosperms).
The hosts of parasites can be bacteria, actinomycetes, plants and animals of all taxonomic groups.
Parasites cause weakening and depletion of the host organism, and often its death. For the passage of the cycle of development of parasites, a change of 2-3 hosts is sometimes required.
Parasites arose in the course of the historical development of organisms from free-living forms. The adaptation of parasites to certain living conditions led to the simplification of their organization, the development of special fixation organs, the enhanced development of the genital organs, anoxybiotic respiration, which makes it possible to exist in an oxygen-free environment, etc.
Many parasites are the causative agents of a number of diseases in humans, animals and plants.
2.2. Plants are parasites
In Indonesia, in the dense jungles of Sumatra, you can find plants with giant flowers reaching almost a meter in diameter. The weight of one flower is about 6 kg. It is similar in color to raw meat and emits a rotten smell. Flies hover over the flower, attracted by its "scent". They aid the plant in cross-pollination.
An unusual plant is called Arnoldi's rafflesia. Its flowers are the largest known in the world. The short, thick stalk of the rafflesia sits directly on the roots of the cissus vine (a close relative of the vine). Thick roots of the liana stretch along the soil surface. In addition to blossoming flowers, numerous buds are visible on them. It is easy to mistake these flowers for the flowers of the liana itself. But flowers never appear on the roots. Where, then, is the body of the plant to which the flower belongs? Where are his shoots with leaves, where are the roots? There is none of them. In the roots of cissus, partly in its wood and between the bark and wood, there are strands of cells alien to the liana. These are rafflesia cells. With them, she sucks nutrients from cissus. A rafflesia flower develops at the upper ends of the strands. Rafflesia is a parasitic plant. It has no roots, no green leaves, where the process of photosynthesis would take place. It feeds on cissus.
It is clear that for the host plant such cohabitation with the parasite is not in vain: the roots, on which the parasite settled, eventually die off. In the fleshy fruits of rafflesia, a huge number of seeds ripen. An elephant or other large animal, passing through the jungle, can step on these fruits, then the rafflesia seeds stick to its feet.
If the animal then again steps on the cissus root somewhere, the seeds of the parasite plant will fall on it and germinate. The sprout from the seed will make a hole in the bark of the cissus and give rise to cell strands that will develop between the living cells of the host plant and suck out nutrients from them.
Another parasitic plant is widely known - dodder. Its very name says that it wraps around the host plant. There are many species of dodilia, and they parasitize on various plants, mainly herbaceous, both wild and cultivated. Clover, alfalfa, flax and hops are especially affected by dodder. The suction cups at the ends of its shoots grow into the tissues of the host plant and suck out water and nutritious juices from it. The dodder has no roots or green leaves. On its shoots, only numerous pale pink flowers collected in glomeruli develop.
All types of dodders found in our latitudes are annual plants. In the fall, their shoots die off. New plants grow from seeds the next year. Seeds that have fallen to the ground and left for the winter germinate in late spring, when other plants have already more or less developed, otherwise there would be no suitable food for the parasite.
Disturbing the metabolism of host plants, dodder greatly weakens them, retards growth and development, often causing death, the yield of plants and the quality of products decrease (the taste properties of fruits, the quality of flax fiber deteriorate, the sugar content in beets decreases, etc.).
Grasses cut for hay, infected with dodder, slowly dry out, mold, lose their nutritional value, and when fed to animals, they cause diseases. Dodder is also a carrier of viral diseases of cultivated plants.
At the same time, dodder in nature is a powerful medicinal plant. Some types of herb are used in folk medicine as a choleretic, seeds - as a diaphoretic, antihelminthic and laxative.
In the forests of our latitudes, the plant-parasite Petrov cross is often found. It develops and parasitizes on the roots of broad-leaved trees - linden, ash, hazel. But you can see it only in early spring, when it appears from the ground for a short time. A low pink-white stem with a one-sided raceme of crimson-red flowers emerges on the surface of the earth. The stem soon dies off, but the parasite plant continues to live underground in the form of a perennial fleshy scaly rhizome weighing up to 5 kg.
Peter's cross is interesting because it never has green leaves. He just doesn't need them. It sticks to the roots of some trees and shrubs and takes the necessary nutrients from there. That is how he lives. The main part of the plant is a highly branched powerful rhizome, which is located underground and penetrates to a considerable depth. It is from the rhizome that aerial white-pink shoots that bear flowers grow in spring. Thin roots also grow from the rhizome, which, at the point of contact with the roots of the host plant, form special thickenings - suckers. Leading a parasitic lifestyle, Peter's cross could never rise to the surface - it is always provided with food. But life consists not only of food, it is also necessary to leave offspring. And Peter's cross is forced to get out of the ground.
Its flowers contain nectar, they are eagerly visited by bees and bumblebees, which produce pollination. Pretty soon, fruit-boxes with black seeds, the same as those of the poppy, are formed from the flowers.After ripening, when all the seeds have already spilled out, the earthly life of Peter's cross ends, its shoots dry up. Not a trace remains of them. And the Peter's cross itself goes underground again for many months. And maybe for years to come. Sometimes Peter's cross does not come out of the ground even in spring.
Great harm to forestry, gardens and parks is caused by tinder fungi, which destroy the wood of trees. Spores of tinder fungi enter the wound on the bark of the tree, germinate and form a mycelium.
The mycelium spreads through the wood and destroys it, making it rotten. Trees affected by tinder fungus become fragile and easily destroyed in their trunks, hollows are formed, and the life of the tree is significantly reduced. Several years after infection with the fungus mycelium, fruiting bodies appear on the bark of the tree. They are hoof-shaped and are usually very hard. There are small tubes on the underside of the fruiting body. It is in them that disputes ripen. To prevent fungi from tinder fungus infection, trees need to be protected from branch breakage and bark damage.
The lifespan of a tree affected by tinder fungus is greatly reduced, since hollows appear in the trunks, they become fragile and easily break.
Chaga is a perennial fungus of the tinder family, parasitizing on tree trunks. Chaga can usually be found on the trunks of old birches, sometimes it affects such trees - alder, elm, maple. Only birch chaga has a useful property. Like other mushrooms, chaga reproduces by spores. Falling into a crack in the trunk of a birch, the spores germinate and produce many hyphae, the so-called mushroom filaments, which feed on the sap of the plant. Gradually, the number of mushroom threads becomes more and more, an uneven black growth forms on the bark of the tree, which is called chaga. Chaga can live on a birch for 10-15 years without forming a spore. For medicinal purposes, chaga is collected from live birches. Old crumbling and decaying chaga is not suitable for treatment. Chaga has to be distinguished from another fungus growing on a birch - a false tinder fungus. Its main difference from chaga is in the shape of the mushroom body.
Chaga has three layers: the outer one is black, with a bumpy surface, the middle one is brownish-brown, rather dense, at the break the granular inner is reddish-brown, loose, with yellow veins. On the lower surface of chaga, in contact with the tree trunk, there is no spongy layer, which is typical for other fungi - tinder fungi. What is chaga useful for? Chaga is very popular in folk medicine and has been written about it since the sixteenth century. For treatment, it is used both internally and externally. Chaga is rich in minerals, macro and microelements.
Chaga has general tonic, tonic, antioxidant, immunomodulatory, anti-inflammatory, analgesic, antispasmodic, laxative properties. Chaga mushroom is used for diseases of the gastrointestinal tract. Chaga preparations reduce pain and improve the general well-being of cancer patients. Chaga is used as an anti-inflammatory agent in dentistry.
How are the inhabitants of water arranged?
From the proposed set of features, select only those that correspond to a given plant. (In a more complex version, determine the name of the plant based on these characteristics.)
1. A plant floating in the water column. 1.Long roots. 2. Well developed root hairs. 3. Delicate transparent oval leaves. 4. Flowers are collected in spikelets. 5. Pollen is carried by the wind. 6. The stem is strong, thick. 7. The stem is thin, weak. 8. Roots are poorly developed.
2. A plant floating on the surface of the water.
1. The stem is flat, rounded. 2.Leaves are long. 3. Leaves are scaly. 4. The flowers are large, bright. 5. The rhizomes are thick. 6.Roots are thin, short. 7. The leaf cover is thick, leathery. 8. The stem is covered with a thin skin. 9. Flowers without petals. 10. The upper side of the stem is green, the lower side is reddish.
3. A plant floating on the surface of the water.
1. The stem is long, thick. 2. The stem is covered with bark. 3. Leaves are thick, serrated along the edges. 4. Leaves accumulate air inside. 5. Roots are thick. 6. The leaf blades are dissected. 7.Stem is shortened. 8. Fruits ripen under water. 9. Seeds with lionfish. 10. Forms rosettes of leaves on elongated shoots. 11. Leaves pubescent.
4. A plant that sticks to the bottom at a depth of 4-5 m.
1. Leaves are floating, oval. 2. Leaves without petioles. 3. Stems are long, thin. 4. The petioles of the leaves are long. 5. There are many air ducts in the petioles. 6.Roots are long and thick. 7.Rhizomes are thick, horizontal. 8. Roots almost without root hairs. 9.Leather dissected leaves. 10. Flowers are bright, yellow, on long pedicels. 11. Seeds with feathers. 12. Fruits can swim for a long time.
5. A plant attached to the bottom at a depth of 1 m, near the coast.
1.The first submerged leaves are long, narrow. 2. Above the water, leaves on petioles with a plate in the form of an arrowhead. 3.Roots are thick, long. 4. There are many air passages inside the plant. 5. Leaves are pubescent. 6. The plant is perennial. 7. Fruits are small, they swim for a long time. 8. Fruits quickly get wet and sink. 9. Floating leaves are petiolate, with oval leaf blades. 10. Leaves are covered with thin skin.
Answer: 18.104.22.168.7.9.10 - arrowhead
6. Grass growing on the bottom in shallow waters.
1. Leaves are narrow, tough. 2. The rhizome is thick, hollow inside. 3. Leaves are large, dissected into small lobules. 4. Stems are erect, hollow. 5. The plant is covered with long hairs. 6. Fruits are juicy. 7. Torn off pieces of rhizomes float for a long time. 8.Plant without hairs.
Answer: 22.214.171.124.8 - poisonous milestone
Adapting to life in the forest
1. Plant from the first layer of the forest.
1.The trunk is thick. 2. The stem is thin, green. 3. The trunk is covered with bark. 4. Leaves are small. 5. Leaves resemble needles. 6.The crown is wide, spreading. 7. Crown branches extend from the trunk high above the ground. 8. The shape of the root system depends on the soil. 9. The stem is short.
Answer: 126.96.36.199.7.8 - Scots pine
2. A plant from the second (shrub) layer of the forest.
1.The trunk is thick. 2. The stem is highly branched. 3.The crown is wide, spreading. 4. Leaves are small, light green. 5. Leaves are pubescent. 6. Leaves with wide leaf blades, dark green. 7. Leaves are turned edge to sunlight. 8.Leaf mosaic. 9. Flowers are greenish, small. 10. Flowers are white, in corymbose inflorescences.
3. A plant from the herb-shrub layer.
1.The plant is not tall. 2.Leaves are long, narrow. 3. The leaves are covered with a waxy bloom. 4. Leaves are dark green. 5. Leaves are thin, wide. 6.Leaf mosaic. 7. Stems are thin. 8. Stems lignified, branched. 9. Fruits with lionfish. 10.Long rhizomes. 11. Fruits are juicy, dark, with a waxy coating.
Answer: 188.8.131.52.184.108.40.206 - blueberry
*four. A plant from the herb-shrub layer.
1.Leaves are narrow. 2. The stem is thick, covered with bark. 3. Leaves are wide. 4. Leaves are light green, with a waxy bloom. 5.Leaves are dark green, large. 6. The stem is green, straight. 7. The stem breaks easily. 8. The stem forms many shoots from the base. 9. Apical inflorescences. 10. Flowers are small, inconspicuous, without perianth. 11. The flowers are visible from afar, blue. 12. The perianth is wrong. 13. Flowers without nectar. 14. Flowers give off nectar. 15. Petals turned into nectaries.
Answer: 220.127.116.11.18.104.22.168.15 - wrestler
Determine the habitat according to the adaptive characteristics given in the task. An easier option is to choose the correct answer from several suggested in brackets.
1. The plant has a weak thin stem, delicate transparent leaves, thin roots, almost without root hairs, covered with a thin skin, without stomata. (sandy desert, lake, rocks, forest). Answer: lake.
2. A plant with a thin, erect stem, narrow leaves with a waxy bloom with leaves located edge to the sun with long roots. (forest, lake, rocks, steppe meadow). Answer: steppe meadow.Get full text Prepare for the exam Find a job Pass the course Exercises and training for children
3. The plant is low, with dark green wide leaf blades, leaves are bare, long rhizomes are white, flowers collected in inflorescences. (forest, meadow, pond, bog). Answer: forest.
4. The leaves of the plant are small, densely covered with white hairs. The stem is thin, strong, long roots with numerous root hairs. (lowland swamp, forest, flood meadow, steppe). Answer: steppe.
5. Plant low leaves small roots branched, winding, strong stems curved, creeping, strongly branching at the surface of the substrate, easily form adventitious roots. (forest, rocks, eternal snow, low-lying swamp). Answer: rocks.
6. Shrub with small linear dense leaves, intensively emitting essential oils, their edges are slightly bent down, the stems are highly branched, the adventitious roots easily form the superficial root system. (forest, meadow, raised bog, lake). Answer: a raised swamp.
7. Herbaceous plant leaves with long petioles, collected in a rosette on leaf blades, long glandular hairs, emitting droplets of sticky juice, wintering buds are laid above the previous ones; new roots are formed above the old ones. (lowland swamp, raised bog, lake, meadow). Answer: raised swamp
* Correct errors in the text and answer the question:
1. Researchers of the seas and oceans have discovered an interesting phenomenon: algae growing at different depths differ in color. Brown algae swim closest to the surface, green algae a little deeper, and at the greatest depths red and black algae. How can this be explained?
Answer: Closer to the surface - green, then - brown and the deepest - red algae. Water absorbs light in the red-orange part of the spectrum, therefore, in plants growing at great depths, brown (fucoxanthin) and especially red (phycoerythrin) pigments predominate, capable of absorbing blue and green rays of light. The almost black color of some red algae is due to the concentration of pigments.
2. Only a few plants can live on salt licks. Here they lack moisture. Such an inhabitant of them, like salicornia, sometimes forms single-species communities. It has a powerful root system that penetrates deep into the soil, with the help of which this shrub extracts water.
Answer: ... Salicornia has a poorly developed superficial root system, with the help of which this herbaceous plant obtains water.
3. Mosses are very short plants. Their weak roots cannot suck in water from great depths, and their small size helps to save it, which is why there are so many of them in arid regions.
Answer: Moss has no roots, only rhizoids. Moss sucks in water over the entire surface, so they prefer damp places. In arid regions, mosses actively grow only during humid periods, and during a drought they can dry out very much, but do not lose their viability.
4. Scots pine is a shade-tolerant plant, so it can often be found under the canopy of other trees. It is undemanding to the soil, and grows both in sands and in swamps.
Answer: Scots pine is light-requiring, but its undergrowth can withstand significant shading.
5. In early spring, before the leaves appear, aspen blooms. Its flowers, which form a large amount of pollen and nectar, attract the first insects. The ripe seeds then hang on the mother trees for a long time, gradually crumbling.
Answer: Aspen flowers are inconspicuous, pollinated by the wind, do not form nectar. The seeds, equipped with fluffy hairs, are blown away by the wind, and they do not hang on the plant for a long time.
6. Small seeds of such plants as violets, celandine, corydalis do not have parachutes and cannot fly. They have only small white outgrowths on the sides of the seed. Why do they need them and how do these seeds spread throughout the territory?
Answer: The outgrowths are nutrient-rich and attract ants. They carry the seeds.
1. Which of the two populations is more likely to survive? One consists only of seedlings, and the other includes not only seedlings, but also young and adult plants?
Answer: The second population has more chances to survive, according to the consequences of the law of tolerance.
2. At the edge of the pine forest, numerous pine seedlings appeared. From year to year, the number of growing pines became less and less, although no one touched them. Explain what happened here. What mechanisms led to a decrease in the number of individuals of the species?
Answer: The number of trees in the forest naturally decreases with age (self-thinning of the stand), since at the same time their size increases and the need for water, minerals, and light increases. Weaker, slower growing seedlings die.
3. The Botanical Garden received Scots pine saplings of the same age from three places - from the Kola Peninsula, from central Russia and from the Caucasus. The receiver put them all in one place, confusing the receipts. Is it possible to distinguish between these groups of seedlings and the trees that have grown from them by their appearance? How exactly?
Answer: You can. The pines from the north are the shortest, with smaller needles and a shortened crown shape. As you move south, the needles lengthen, the growth rate increases, and, consequently, the height of the trees. The crown of the southern forms is higher, vertically elongated, and dense.
Protection of Nature (correct biological errors in the text)
1. The yellow lady's slipper is a widespread plant. It is most often found in forests, in fields and on the shores of water bodies. The plant has a large yellow shoe-like flower. It is pollinated by various types of insects.
Answer: This is a rare orchid found in forests and sparse groves. Pollinated by bees.
Features of plant nutrition
By the structural features, determine the food specialization of the plant and name it.
1. Roots are short, thin. Leaves on long stalks. On the leaf blades, they have many long reddish glandular hairs that secrete a sticky liquid. When touched, the leaf blades can curl up.
Answer: The insectivorous (predatory) plant is the sundew.
2. Part of the leaf is turned into a bright jug filled with thick juice. The edges of these jugs are bent inward and seated with bristles. Above there are reddish grooves, between which sweet fragrant juice. The edges and inner walls of the jugs are very smooth.
Answer: The insectivorous (carnivorous) plant is nepentes.
3. An aquatic plant without roots, with thinly dissected leaves. At the ends of the leaf lobules, there are sacs with valves that can slam shut and reopen. The edges of the sac opening are seated with bristles directed inward.
Answer: A carnivorous plant that feeds on aquatic invertebrates is pemphigus.
4. Thin yellowish stem. Leaves are invisible, in the form of scales. There are no roots that attach the plant to the soil. There are special roots that penetrate the tissues of other plants.
Answer: The parasitic plant is dodder.
5. Yellowish or reddish plant. The roots easily penetrate the roots of other plants. Only very large bright inflorescences are well developed. Lots of seeds.
Answer: Plant-parasite (broomrape).
Man affects nature
Describe the environmental consequences of human actions.
6. Since autumn, a lot of dry yellow grass has remained in the glades and around the houses. Young greenery cannot penetrate through it. It is best to set fire to old grass and make sure that nothing from it catches fire. Thus, we will give room for the germination of fresh greenery.
Answer: Such burning (fell) is very harmful. The fire kills many small animals, shoots and seeds of many plants, and burns out the humus-rich topsoil. The soil loses the accumulated moisture faster and slows down the falling precipitation worse. In this case, plant growth is delayed.
7. In the spring, fires are usually allowed, setting fire to the old, last year's grass. They say it accelerates the growth of young grass, and in addition, fertilizes the soil with ash. Is it so?
Answer: Spring fell does not accelerate the growth of new grass, but slows it down - destroying the aboveground parts of plants and damaging the underground organs of many of them. The resulting ash is a small compensation for the burnt fertile layer.New humus is no longer formed this year, since all the old grass and fallen leaves have burned out.
*eight. To avoid massive encephalitis diseases, they decided to destroy ticks in the suburban forests. To this end, dry grass and leaves were burned out in forests, bushes and along roadsides. --- Pests destroyed crops in local gardens.
Answer: Burning dry grass and litter in spring only slightly reduces the number of encephalitis ticks. - But many predatory insects, shrews and other inhabitants of the forest and meadow litter are destroyed. The already built ground nests of birds burn down, and there is nothing to make new ones, all the building material has burned out. - Making nests on a fire, open from all sides, is an unsafe business. Birds leave such places. - New grass regenerates here more slowly, because the fire kills seeds, buds and barely appeared shoots, and the underground parts of plants and fungi are damaged. - The species diversity of both animals and plants is decreasing. Local trees and shrubs are weakened (the bark of the trunks and the crown is burned). - Various consumers of bark, wood, leaves flock to the places of fires, to weakened plants. In the absence of predatory animals, they reach large numbers, destroying the forest. - And finally, when moving to the surrounding gardens, these insects damage cultivated plants. Applying pesticides against pests, a person aggravates the situation even more.
To the genus dodil - Cuscuta, flowering parasitic plants are the most dangerous for cultivated plants, combining great vitality with high fertility. Dodder comes from tropical America and Africa, from where it spread to the north and south, gradually adapting to new conditions and plants and distinguishing new species (up to 100 species are described).
Not to be confused with the loach, although they are related.
In our country, there are more than 30 types of dodders. All of them are objects of internal quarantine. The most widespread and harmful: dodder field - Cuscuta campestris, dodder clover - C. trifolii, dodder hop - C. lupuliformis, dodder linseed - C. epilinum, dodder short-flowered pepper - C. breviflora, dodder of leman - C. lehmaniana. These are aerial parasites, the body of which has turned into a filamentous or cord-like, curly, yellowish, greenish-yellow or reddish smooth or warty stem, devoid of chlorophyll, with barely noticeable traces of leaves in the form of scales. Plants are rootless, feed on and attach to the host plant with the help of suckers - haustoria, which are formed in places of contact with the feeding plant and deeply penetrate into its tissue. The suction of nutrients occurs due to the higher osmotic pressure of the parasite's cell sap.
the initial period of development, seedlings receive nutrients from seed reserves. The sprout can “crawl” for a short distance due to the movement of nutrients from its base to the top. Such an independent existence can last 16-25 days, while there are known cases when the length of the seedling reached 30 cm or more.
If the parasite does not meet a plant suitable for infection, it dies.
The attachment of the parasite to the host and its feeding are carried out with the help of haustoria, which are formed on the filamentous stem of the dodder from the side adjacent to the stem of the host plant. The substances secreted by the suction cups soften the epidermis, which facilitates the penetration of the parasite into the tissue of the feeding plant. If conditions are acceptable, the inside of the suction cup expands to form a wedge-shaped fluke.
The emergence of seedlings is extended for several years.
In the fight against dodder, preventive measures are of great importance. Sowing is carried out with seeds cleared of dodders. They carry out approbation of crops on the vine, phytopathological examination, quarantine measures. Sowing with seeds contaminated with dodder is prohibited according to state standards.
The main source of contamination of crops with dodder is the soil, in which large reserves of parasite seeds accumulate. Therefore, for sowing, they choose non-contaminated areas (according to field approbation data) or clean the soil. Cleaning of the arable horizon is carried out either by planting dodder seeds to a great depth using plows with skimmers, or by stimulating their germination with subsequent destruction of seedlings by surface treatment. In areas of irrigated agriculture, seed germination is stimulated by provocative autumn and spring watering.
From the crops of alfalfa and clover, which are most often infested with dodder, the parasite spreads to other crops, primarily those that follow them in the crop rotation. Therefore, on infected fields, the affected crops are excluded from the crop rotation for 5-6 years.
If the dodder appears in the crops of perennial grasses (clover, alfalfa), they are mown before the beginning of flowering or seeding of the dodder. Timely mowing is especially effective against field dodders, 95% of whose stems are located at a distance not exceeding 5 cm from the soil surface, and with a low cut they can be easily removed from the field along with hay.
This plant has no roots or leaves. Only a filamentous or thin cord-like stem, equipped with haustoria, a kind of suction cups. Which the parasite inserts into the stems and leaves of the victim plant and feeds on its juices. Dodder blooms with small (about 2 mm) inconspicuous flowers, forming spherical inflorescences.
Fruit capsules with 1-3-4 irregularly rounded seeds. Each parasitic plant is capable of forming up to 100 thousand seeds. Moreover, unripe seeds are able to germinate faster than mature ones. And the germination of seeds that have fallen into the soil can last up to ten years. Seeds that have passed through the gastrointestinal tract of animals do not lose their germination. And a germinated seed in search of a plant-"breadwinner" can cover a distance of 25-30 cm. One involuntarily suspects they have intelligence.
Dodder bush can produce up to 100 thousand seeds
By sucking juices from the host plant, dodder weakens it. As a result, not only productivity and yield decreases, but sometimes the complete death of crops. The parasite can serve as a carrier of viral plant diseases.
Dodder is dangerous not only for plants, but also for animals. If a plant entwined with a parasite gets into the hay, it can cause severe poisoning in the animal that has eaten it.
Message Mimoza »14 Jun 2016 00:17
You are very "lucky" to have been brought to the site of a quarantine pest - dodder. This is a parasitic plant, carefully monitor the plants and carefully remove it, it digs into the stems with suckers and sucks the juices from the plants.
her shoots look exactly like this, and then she will simply live on the owner, having no roots from the earth.
Very carefully you need to remove and destroy it, and not let it creep, and not give the opportunity to bloom
I can't imagine, however, how to remove it from young shoots, I had it on raspberries and currants, everything was much easier, in one season I exterminated it, but along the road I see how it periodically covers the grass with a yellow cloud
Message ROSSI »14 Jun 2016 00:34
Message Pavel »14 Jun 2016 08:25
Message Kot vasya »14 Jun 2016 09:39
In Ussuriisk, a few years ago, a poster was hung in the quarantine service warning about the danger of this quarantine plant.
By the way, the povelika also came to us along with the imported cattle manure. At times I won by hand sampling, fortunately, then the povelika was divorced on an area of only 30 sq. M. No more. Of course, it's hard to clean up manually, unraveling. And as it grows up, it bites into the shoots of cultivated plants and is already very difficult to separate. It is necessary to choose in the early stages, especially as long as the seeds are not given.
Message Relh »14 Jun 2016 09:54
Message Nikolay Ivanovich »18 Jun 2016 00:57
Parasites are plants that either completely lost their ability to photosynthesize (broomrape), or retain it to a small extent (dodder).
Dodder (Cuscuta) is a climbing plant. When dodder seeds germinate, the root tip bends and partially sinks into the soil. The filamentous spiral seedling is elongated, and its apex rotates. The direction of travel is controlled by chemicals released by the host plant. Then the root end dries up, and the stem is twisted around the host plant. With the help of suckers, the dodder is attached to the stem and receives all the necessary nutrients from the host plant. Dodder often leads to the death of crops of cultivated plants. It is especially harmful to clover crops.
from the book Physiology of Plants by N.I. Yakushkin.
There may be several reasons. The first is the proximity of groundwater. If this is the case, it is better to plant trees on bulk hills with a height of 1-1.5 m. And not just any, but on weak or medium-sized (clonal) rootstocks: their root system suffers less from blocking.
You can determine the groundwater level by looking into pits, ditches, wells, wells nearby or by drilling your "hole" with a garden drill. It is better to do this in July. If the water is at least 1.6 m - the place is suitable for an apple tree.
In addition to very damp areas, sandy and sandy soils, poor in organic matter, are not suitable for growing a garden, they also hold moisture poorly, and in cold winters with little snow they cannot protect the roots from freezing. In this case, the planting hole should be made deeper than usual: 1.2 m deep and 1.2-1.5 m in diameter.A layer of clay should be poured at the bottom - 10-15 cm.Then, three weeks before planting the seedling, fill the hole with black soil or peat with clay soil (equally). The earth must settle before planting. By the way, on the sands it is better to plant trees on vigorous rootstocks.
Another reason for poor tree growth is poor quality planting material. The variety should be zoned in the region, the seedling should be one, two or three years old, healthy, with a well-developed root system, without necrosis in the area of the root collar and without drying tops. At the same time, it is better not to take seedlings brought from the south: they may not adapt to more severe conditions, stop growing and die in four to five years. Is this not the case with you?
Moreover, a new fruit tree should not be planted where another fruit tree previously grew, especially if it has died. If more mature fruit trees are already growing on the site, then before planting a new one, they should remove all dried branches, as well as branches with dead bark. The stumps must be cleaned and whitewashed, the stumps must be uprooted. And for a young seedling after the "housewarming" it does not interfere with whitewashing the base of the trunk before the first fork.
If the seedling has been grafted, inspect the root collar of the tree. It should be at ground level. If it is deeper, the tree grows poorly. There are several ways to lift it.
Put a lever under the lower branches (for an apple tree seven to eight years old - a long strong log) and tie it to the trunk. Under the lever, you need to make a support from logs, and at the other end hang a small barrel and fill it with sand, then the lever will strongly pull the apple tree up. In order for the process to proceed reasonably, it is also necessary to put a support under the bottom of the keg - a limiting one.
After that, you need to dig out the trunk circle a little and pour water into it from a hose. The water should wet the soil for several days in a row. Sometimes, on the second day, the barrel goes down, and the apple tree rises up. So the tree can be raised by 5-6 cm at a time.
If you are friendly with neighbors, you can call them for help. First, next to the apple tree, you need to pour a pile of soil mixed with fertilizers. Then, along the perimeter of the crown, dig in a lump with a shovel, hammer shovels under it from three or four sides and, unanimously bending the shovels towards yourself, lift the lump. Another person should immediately fill the prepared earth under the tree. Then the root ball is carefully lowered onto it. Of course, it will partly fall apart, but the main roots will remain with the earth. The apple tree will not get very sick.
You can do it easier. Remove excess soil to a depth of 10 cm within a radius of 1.5 m from the apple tree trunk, shield this hole so that water and wind do not bring the earth back, and keep it under black steam. If you are afraid of trapping the roots, you can make a water diversion groove in a lower place than the hole in the tree. But even good rain is only 20-30 mm of precipitation. Water is quickly absorbed and still has to be watered. So the outlet will only be needed for thawed spring waters.
Tell me what kind of weeds it is: yellow threads and everything braids and sticks to everything. How to deal with it?
I do not remember the name of this plant, but I know for sure that this is a parasite plant, it feeds on the plant, the only fight against it is to remove it along with the plant, just do not leave a single piece of this parasite on your site.
This is a dodder, it is difficult to fight with it. You need to choose it all clean and take it away from home or try to dry it and then throw it away. This parasitic plant has no roots, it feeds on the plant itself, braiding it sucks all the moisture, and itself grows.
Yes, it's dodder. If the dodder gets to the bushes, do not spare the branches from which you cannot peel the stems of the dodder, and be on the lookout, constantly examine the place where the dodder was, if you do not find it this year, it may appear again next year, do not forget! Dodder grows very quickly, forms a lot of seeds, is carried by the wind or birds. Dodder seeds do not lose germination in the soil for up to 10 years!