Weed control is carried out on every household plot. They litter the soil, take nutrients from cultivated plants. But there are weeds, the fight against which is carried out on a national scale. These weeds are particularly harmful and are called quarantine weeds. Weed infestation adversely affects agriculture:
- Reduces the amount of the crop or leads to its complete death;
- Reduces productivity of pastures;
- Clogs and degrades the quality of the harvested grain, reduces the quality of harvesting, disables 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;
- It leads to a violation of the composition and structure of the local plant community, the displacement of previously growing grasses, which negatively affects the fauna of the region;
- Causes damage to livestock, because 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 “strangers” will behave, but as practice shows, weeds are more aggressive in a new place than in their usual growing environment, because at home they have natural enemies: pests, diseases, other biofactors, and in new places these plants have no natural enemies. To protect farmland from contamination by 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 movement of these goods, and quarantine weeds are controlled domestically.
Quarantine weeds growing in Our Country
The following quarantine weeds grow on the territory of our country:
- Dodder.
- Gorchak creeping.
- Ambrosia polynnolistnaya.
- Ambrosia trehrazdelnaya.
- Ambrosia is a perennial.
- Prickly nightshade.
- Nightshade three-flowered.
The article will present photos of harmful herbs and methods for combating quarantine weeds.
dodder
It can be said that all varieties of dodder are the most dangerous parasitic weeds. They are extremely prolific and viable. 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 Our Country. The most dangerous and common are field dodder, clover, hop, linseed, short-flowered pepper and lehman dodder.
dodder danger
Dodder lacks a root system. Dodder feeds by attaching itself to the host plant with suckers. Suckers (haustoria) penetrate deep into the tissue of a cultivated plant. The stems of the weed are almost devoid of chlorophyll, filamentous, curly, covered with scale leaves and numerous small flowers. As a host plant, dodder use perennial and annual herbs, trees, shrubs, vineyards. Sucking out all the juices, dodder disrupts 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-infested grasses loses its nutritional properties, quickly becomes moldy, and contributes to disease and death of animals. Dodder, penetrating into plants, carry viral diseases.
The distribution of dodder occurs mainly with the seeds of cultivated species with their insufficient cleaning. If hay infected with dodder gets into the livestock feed, then the weed seeds will fall with manure on the areas fertilized by it. Dodder seeds are similar to the seeds of the host plants, this is the result of parasitic adaptation, and it complicates the cleaning of cultivated grass seeds.
Methods of struggle
The main way to counteract the spread of dodder is preventive measures:
- seed cleaning;
- soil testing;
- approbation of crops;
- quarantine measures;
- phytopathological examinations;
- cleaning of the arable horizon;
- stimulation of dodder germination with the destruction of these shoots;
- provocative autumn and spring watering;
- exclusion for 5-6 years from the crop rotation of crops affected by dodder.
Gorchak creeping (pink)
This perennial root weed grows in vineyards and orchards, pastures and meadows, along highways, on railroad slopes and wastelands.
Harmfulness of bitterness
The plant has a powerful root system, its main vertical root penetrates the soil more than ten meters deep and has an extensive system of horizontal roots. Propagated by both seeds, their germination in the soil is 3-5 years, and rhizomes. Gorchak spreads with poorly cleaned seed, with straw and hay.
The root system of the mustard grows very quickly, depriving cultivated plants of moisture and minerals and reducing their yield by half. One weed plant during the year grows into a curtain of 5-6 m in diameter, and its intertwined roots do not give any chance to cultivated plants. Light-loving mustard does not form seeds in shady areas, the growth of its root system slows down, but retains the ability to explosive growth 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 mustard will completely lose their germination;
- inclusion in livestock feed of grain waste contaminated with weed seeds, only ground or steamed.
mechanical methods:
- systematic mowing of weed foci before it begins to bloom on empty lands and in fields;
- before harvesting the main crop, mowing clumps of mustard, followed by burning the mowed mass of the plant.
agrotechnical methods:
- pruning the root system and darkening weed curtains;
- a combination of black fallow (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 moths, mustard nematodes, 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 a massive aerial part of the weed oppress cultivated plants. During the growing season, ragweed literally sucks water and minerals out of the soil, dries up and depletes the soil, obscures cultivated plants, displacing them from fields and pastures. During its flowering period, the weed releases a huge mass of pollen, causing severe allergic reactions. Ambrosia blooms from July to October. An annual plant reaches a height of 1,8 m, the taproot goes deep into the soil by 4 meters. Ambrosia propagates by seeds, the number of which from one bush can reach 40 thousand. High germination is also observed in unripened 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.
Methods of struggle
Traditionally, agrotechnical, biological and chemical, and the most effective method is the correct agricultural technology. Crop rotation, care of crops, prevention of re-inoculation of the soil with weeds. When destroying ambrosia in summer cottages and adjacent territories, the weed should be destroyed with the root, because. after mowing, several new ones grow in place of one stem. Combining agrotechnical methods with the use of herbicides permitted on the territory of the Federation, it is possible to contain the spread of ragweed.
Ambrosia trehrazdelnaya
Annual plant, spring weed of large size, its stem becomes stiff by autumn. It has many similar properties with ragweed, differing in early maturation, larger seeds and their buoyancy, due to which the onset of infection occurs in low-lying, flooded areas. Distribution, harm and methods of dealing with this weed are the same, but this type of weed is best destroyed by chemical means, because. it has more leaf surface.
Ambrosia perennial
Perennial, root weed. The main root of the plant is taproot, has numerous processes from which new above-ground shoots grow. Often found in pastures, meadows. Not displaced by perennial grasses, plant rhizomes are resistant to frost. This weed is difficult to eradicate, causes a decrease in the yield and quality of cultivated plants, and reduces the productivity of pastures. this weed is not eaten by livestock.
Methods of struggle
Destruction of weed rhizomes with herbicides, prevention of clogging of seed, mowing or weeding before it is seeded. With heavy weed contamination, the field is taken away under clean fallow, this is a kind of quarantine method. In autumn, 2-3 peelings are carried out, and 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. In the next season, winter wheat is sown.
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, it bears fruit from August to October. About 180 berries ripen on each plant, each of which contains from 50 to 120 seeds, which acquire germination after wintering and retain 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, move 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 builds up 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. Weeds crops, pastures, vegetable gardens and orchards. The branched root system of the weed deprives cultivated plants of nutrition and water. Yield loss in infected areas is 40-50%.
Straw, in which nightshade thorns have fallen, is not even suitable as bedding for livestock. Nightshade serves as a host plant for potato moth, Colorado potato beetle and some viruses.
Methods for combating this weed include a complex of agrotechnical and chemical measures.
Nightshade triflorum
Came from North America, distributed in central Europe. In Our Country, it was found in Altai and in the Omsk region. Herbaceous weed is an annual plant with high seed productivity. On one plant, 10-14 thousand seeds ripen, and their germination capacity lasts for 9 years. Forms large bushes with hard branches. This weed is able to give adventitious roots from the stems and take root easily. A weeded plant left on the ground easily re-roots. Nightshade seeds are sticky, so they stick to various objects and spread over long distances. The weed is poisonous, has an unpleasant putrid smell.
Methods of struggle
Prevention: cleaning of seed and fodder grain, the processing of which must be carried out according to technology that deprives the seeds of germination. To bring to the fields should be rotted manure, 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 may be used.
Conclusion
When destroying weeds in your area, pay attention to whether you have grown any quarantine weed that can nullify all your efforts to grow cultivated plants.