Content
On each personal plot there is a struggle against weeds... They litter the soil, take nutrients from cultivated plants. But there are weeds that are being fought on a national scale. These weeds are especially harmful and are called quarantine weeds. Weed infestation adversely affects agriculture:
- Reduces the amount of the crop or leads to its complete death;
- Reduces the productivity of pastures;
- It litters and degrades the quality of the harvested grain, reduces the quality of harvesting, disables the harvesting equipment, leads to additional costs for cleaning the crop from seeds of harmful plants;
- Promotes infection with viruses and bacteria that are dangerous for cultivated plants, the development of pests of agricultural crops;
- Leads to disruption of the composition and structure of the local plant community, displacement of previously growing grasses, which negatively affects the fauna of the region;
- Causes damage to livestock, since some types of weeds are toxic to livestock;
- Causes allergic reactions in humans.
The development of interstate trade relations leads to the transfer of plants from one habitat to another. It is difficult to predict how the "outsiders" will behave, but as practice shows, in a new place weeds are more aggressive than in the usual growing environment, because in their homeland, they have natural enemies: pests, diseases, other biofactors, and in new places these plants do not have natural enemies. To protect farmland from contamination with dangerous weeds, quarantine measures have been developed in many countries of the world to reduce the risk of contamination of the area. Taking into account that weed seeds can be transported with imported grain, seeds and breeding animals, quarantine control is carried out over the transportation of these goods, and quarantine weeds are being controlled within the country.
Quarantine weeds growing in Russia
The following quarantine weeds grow on the territory of our country:
- Dodders.
- Creeping gorchak.
- Artemisia ragweed.
- Ambrosia is tripartite.
- Perennial ragweed.
- Thorny nightshade.
- Three-flowered nightshade.
The article will present photos of harmful herbs and methods of controlling quarantine weeds.
Dodders
We can say that all varieties of dodder are the most dangerous parasitic weeds. They are extremely prolific and resilient. Originating from tropical latitudes, dodder has spread almost all over the world, successfully adapting to new conditions for itself, forming new subspecies. There are thick and thin-stemmed forms. More than 30 species of dodder grow on the territory of Russia. The most dangerous and widespread are field dodders, clover dodders, hop-like, flaxseed, short-flowered peppercorns and leman dodders.
Danger of dodder
Dodder has no root system. They feed on dodders, attaching themselves to the host plant with suckers. The suckers (haustoria) penetrate deeply into the tissue of the cultivated plant.The stems of the weed are almost devoid of chlorophyll, filamentous, curly, covered with leaflets, scales and small numerous flowers. Perennial and annual grasses, trees, shrubs, and vineyards are used as the host plant for dodders. Sucking out all the juices, dodders disrupt the metabolism of the "host", the plant is weakened, lags behind in growth and development. Quite often, entire arrays of cultivated plants infected with the parasite die. Hay obtained from weed-infected grasses loses its nutritional properties, quickly grows moldy, contributes to disease and death of animals. Dodders, penetrating into plants, carry viral diseases.
Dodder spreads mainly with seeds of cultivated species with insufficient cleaning. If hay contaminated with dodder gets into the cattle feed, then the weed seeds will fall with manure on the areas fertilized by it. Dodder seeds are similar to those of host plants, it is the result of parasitic adaptation, and it complicates the seed cleaning of cultivated grasses.
Control methods
The main way to counter the spread of dodder is preventive measures:
- cleaning seeds;
- soil approbation;
- crop approbation;
- quarantine measures;
- phytopathological examinations;
- cleaning the arable horizon;
- stimulation of dodder germination with the destruction of these seedlings;
- provocative autumn and spring watering;
- exclusion of crops affected by dodder from crop rotation for 5-6 years.
Creeping mustard (pink)
This perennial root sucker weed grows in vineyards and orchards, in pastures and meadows, along highways, on railroad slopes and in vacant land.
The harmfulness of bitterness
The plant has a powerful root system, its main vertical root penetrates into the soil more than ten meters deep and has a branched system of horizontal roots. Propagated both by seeds, their germination in the soil is 3-5 years, and by rhizomes. Bittersweet is spreading with poorly cleaned seed, with straw and hay.
The root system of bitterness grows very quickly, depriving cultivated plants of moisture and minerals and reducing their yield by half. One weed plant for a year, grows into a clump of 5-6 m in diameter, and its intertwined roots do not give any chance to cultivated plants. Light-loving bitterness does not form seeds in shaded areas, the growth of its root system slows down, but retains the ability to grow explosively when favorable conditions occur.
How to fight
Preventive measures, including:
- seed cleaning;
- the use of manure composted for 3-4 months, only in this way the seeds of bitterness will completely lose their germination;
- inclusion of grain waste contaminated with weed seeds, only milled or steamed, into livestock feed.
mechanical methods:
- systematic mowing of weed foci before the beginning of its flowering on empty lands and in fields;
- before harvesting the main crop, mowing bitterness clumps, followed by burning the mowed mass of the plant.
agrotechnical methods:
- pruning of the root system and darkening of the weed clumps;
- a combination of black steam (20-25% of the area) with crops that suppress bitterness with their powerful green mass (rye, oats, barley, alfalfa);
- stubble plowing, autumn plowing and autumn rise of black fallow;
- the use of chemical agents (targeted herbicides) and biological agents, such as fruit flies, bitter nematodes, and kidney gall midge.
Artemisia ragweed
Came to our continent from North America and quickly spread, causing significant damage to agriculture and human health.Powerful roots and massive aboveground part of the weed oppress cultivated plants. During the growing season, ambrosia literally sucks water and minerals from the soil, dries up and depletes the soil, shades cultivated plants, displacing them from fields and pastures. During its flowering period, the weed emits a huge mass of pollen, which causes severe allergic reactions. Ambrosia bloom lasts from July to October. The annual plant reaches a height of 1.8 m, the taproot extends 4 meters deep into the soil. Ambrosia propagates by seeds, the number of which from one bush can reach 40 thousand. High germination rate is also observed in unripe weed seeds. The plant is well adapted to flooding and frequent mowing. The photo shows the size of the plant and the scale of the disaster.
Control methods
Traditionally, agrotechnical, biological and chemical, and the most effective method is correct agrotechnology. Crop rotation, care of crops, prevention of re-seeding of the soil with weeds. When destroying ragweed in summer cottages and adjoining territories, you should destroy the weed by the root, because after mowing, several new ones grow in place of one stem. Combining agrotechnical methods with the use of herbicides permitted in the territory of the Russian Federation, it is possible to contain the spread of ragweed.
Ambrosia tripartite
An annual plant, a large-sized spring weed, its stem stiffens by autumn. It has many properties similar to ragweed, differing in early ripening, larger seeds and their buoyancy, due to which the beginning of infection occurs in low-lying, flooded areas. Spread, harm and the methods of controlling this weed are the same, but this type of weed is better destroyed by chemical means, because it has a larger leaf surface.
Perennial ragweed
Perennial, root-sprouting weed. The main root of the plant is taproot, has numerous shoots from which new aerial shoots grow. Often found in pastures, meadows. It is not supplanted by perennial grasses, plant rhizomes are frost-resistant. This weed is difficult to eradicate, causes a decrease in the yield and quality of cultivated plants, weakens the productivity of pastures, because this weed is not eaten by livestock.
Control methods
Destruction of weed rhizomes with herbicides, prevention of seed clogging, mowing or weeding of weeds before seeding. In case of heavy weed contamination, the field is taken away under clean fallow, this is a kind of quarantine method. In the fall, 2-3 peeling is carried out, and the plowing of steam is carried out in the spring, after mass shoots of the weed. Subsequently, this field is cultivated several times in layers with simultaneous harrowing. The next season is the sowing of winter wheat.
Prickly nightshade
Emigrated to Europe from North America. All parts of the plant are densely covered with thorns. The diameter of one plant is about 70 cm, bears fruit from August to October. Each plant ripens about 180 berries, each of which contains from 50 to 120 seeds, which acquire germination after wintering and keep it for 7-10 years. After the seeds ripen, the plant breaks off and rolls over long distances. Weed seeds are carried by the wind, transported on the wheels of vehicles. The main root of the plant grows into the soil to a depth of 3 meters. Under favorable conditions, the ground part of the weed grows a huge green mass about a meter high. It grows on roadsides, wastelands, displacing all other grasses from there. The lack of light at the beginning of the growing season of the plant has a depressing effect on it. Infests crops, pastures, vegetable gardens and orchards. The branched root system of the weed deprives cultivated plants of food and water. The yield loss in the infected areas is 40-50%.
Straw, which has fallen into nightshade thorns, is not even suitable as bedding for livestock. The nightshade serves as a host for the potato moth, Colorado potato beetle and some viruses.
Methods for controlling this weed include a complex of agrotechnical and chemical measures.
Three-flowered nightshade
Came from North America, distributed in central Europe. Found in Russia in Altai and in the Omsk region. Herbaceous weed is an annual with high seed productivity. 10-14 thousand seeds ripen on one plant, and their germination persists for 9 years. Forms large bushes with hard branches. This weed is capable of giving adventitious roots from the stems and is easy to root. A plant removed by weeding and left on the ground can easily be re-rooted. Nightshade seeds are sticky, so they stick to various objects and are carried over long distances. The weed is poisonous, has an unpleasant cadaveric odor.
Control methods
Prevention: cleaning of sowing material and fodder grain, the processing of which should be carried out using a technology that deprives seeds of germination. Rotted manure should be applied to the fields, in which all weed seeds have lost their vitality.
Agrotechnics: flat-cut soil cultivation, crop rotation, harrowing, inter-row cultivation of row crops. Recommended herbicides can be used.
Conclusion
When destroying weeds in your area, pay attention to whether you have grown any quarantine weed that can negate all your efforts to grow crops.
