Weed plants

Weeds are plants, the growth of which seriously hinders the crops of crops. Weeds multiply easily. These plants belong to poisonous herbs, they are found on all continents, but there is no benefit from them.

Not all weeds were originally so. So, for example, if a sunflower that does not belong to weeds plants, sprinkles its seeds, then some of them will sprout in spring and will contaminate crops of cultivated plants. Most often, it is the sowing of winter crops, which are sown in this place after the sunflower.

Weed plants, the number of which has already exceeded a few thousand, cause serious damage to the agricultural sector, and this harm is diverse. They absorb water from the soil in huge quantities, their roots poison the soil with harmful substances. Consuming a lot of water, they differ in rapid growth, respectively, deprive the light of cultural plants, while reducing yield. Sometimes crops even die.

To the serious losses in harvesting leads to the presence of curly weeds such as the bindweed of the field or Highland Highlander. Under their weight there is lodging of agricultural crops, which means that their harvesting will be difficult - and part of the crop will remain in the fields.

Suffer from weeds (buckwheat, sow, etc.) and harvesting machines, their parts are clogged with grass, which leads to a decrease in productivity. At the same time, weeds can reduce the quality of the harvested crop. This is due to an increase in the humidity of the seed and grain when the juicy parts of the weeds fall into the harvested crop.

One can not help but mention one more misfortune. Sometimes seeds of poisonous weeds get into the grain, and then it leads to poisoning of domestic animals, and sometimes a person. Weeds can reduce the yield and nutritional value, and sometimes completely displace fodder varieties of grass from farmland. Weeds leading to siltation of canals for irrigation, in addition, reduce their throughput. And in the hot season, they become a source of fires. Especially dangerous the abundance of weeds becomes in the so-called strip of alienation of oil pipelines or gas pipelines.

Classification of weed plants is made by several criteria: the place of growth, the features of reproduction, distribution and renewal.

By the peculiarities of reproduction, there are three biological groups: perennial and 2 groups of juvenile (seed and vegetative). The group of seed youngsters includes plants that reproduce, propagate and renew with the help of a seed, a fetus or a seed rudiment. They are both annual and biennial.

Weeds-annuals are divided into subgroups. In the subgroup of early spring crops, which are the main pests for early spring crops, quinoa, oats, hemp. A subgroup of late spring crops, littering millet and actively interfering with the development of later spring crops include weeds, which are called bristle, shirits, etc. The subgroup of winter weed plants perfectly tolerates winter, bearing fruit after a year. This group of plants causes major damage to winter crops. A shepherd's bag, a field yakut , can be classified as a wintering group.

Two-year-old weeds live for two years: in the first year of life vegetative organs from the seed appear, and the plant fructifies and dies in the second year of life.

A separate group consists of weed-parasites, they can include a dodder, a broomrape, a late tooth or a large bug. Dodder sucked to the stem of alfalfa, clover or other plants, broomrape is fed from the roots of tomatoes, alfalfa or tobacco, and the last two weeds belong to the semi-parasites.