Слайд 2PLAN
1. The concept of the weeds
2. The dangers of
3. Classification of weeds
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and their common types
4. Smallest annual weeds
5. Ephemeral
6. Winter weeds
7. Biennial weeds
8. Perennial weeds
9. Umbilical vascular weeds
10. The root system of fringe weeds
Слайд 3The concept of the weeds
Weed plants growing in the fields of culture
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that is detrimental to the quality of their products to reduce the amount of plants. Cultural crop rotation and other cultural crops is encountered, it is called the polluting plants. Crop growing faster than weeds, spend a lot more moisture and nutrients..
Слайд 5The dangers of
Shade crop of weeds growing on the top floor, which
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slows down the process of photosynthesis in the leaves, accompanied by the deterioration of agricultural machines, which will cause the class. agricultural machines in their class can cause deterioration of the work.
Слайд 6Classification of weeds and their common types
Nearly 300 species of weeds. Patrolling
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the classification based on several criteria: power plants method, duration of survival, reproduction method. The method of power-minded, semi-minded and not-minded weeds off.
Слайд 7Smallest annual weeds
Life expectancy are divided into 2 groups: one year, a
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lot of the year. One-year survival of weeds process lasts from 1 to 2 years. Their increasing appearance of new growths and early summer, depending on the length of the stages of development of these ephemeral, late summer, winter and the year is divided into two.
Слайд 8Ephemeral
Ephemeral stages of growth and development in a very short (1.5-2 months)
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plants. They can be several generations per season. In this group, the most harm to black oats.
Слайд 10Winter weeds
For the development they need to lower the temperature of the
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winter season. Despite the terms of new growths, the plants will spend the winter, and fruit in the summer of next year. With winter cultural crops grow and mature at the same time the family. Representatives: rye, barley field.
Слайд 11Biennial weeds
Plants to complete within two years of their life. First formed
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in the root system and leaves the stork. Representatives of this group meñdwana black, white and yellow camel alfalfa, etc.
Слайд 12Perennial weeds
They grow a few years. Оnly members of the surface of
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the soil in the winter dies. Winter roots will continue to grow next year. They can grow and go through the veins through the family. Representatives of the main field ivy, creeping repens, fiber spurge, etc.