There are currently 6,000 different species of weeds. Those that grow in meadows are used as livestock feed. Others, growing on cultivated fields and gardens, become pests. Particular damage is caused by those weeds that are cereals.
Weed species
All weeds are divided into two types: monocotyledonous and dicotyledonous. Such a distribution is very important in the fight against them, because in order for the work to eliminate them to be effective, you need to know which of these classes this or that plant belongs to. They should not be left in the fields or gardens, since they cause significant damage to the crop, and sometimes cultural crops that cannot survive in an unequal struggle can completely die.
Difference between species
Clear differences between monocotyledonous and dicotyledonous cereal weeds are defined. They consist in the following botanical features:
- In monocotyledons, there is one cotyledon in the grain germ, and in dicotyledons, two.
- The former have a fibrous root, the latter - rod.
- The leaves of monocotyledonous weeds are always simple; in dicotyledons, they can have a different structure. Plants with a complex leaf plate between two germinal buds on the stem throw a new one.
- In monocotyledons, the perianth is only simple, and in dicotyledons, it is double.
- Plants of the first group are deprived of educational tissue in the stems and roots, while in the second it is present.
Among cereal weeds, representatives of the dicotyledonous species growing on the field of sowing crops of the same family are more common.
Species representatives
The names of cereal weeds are often associated with their appearance or some botanical differences. Here is a list of monocotyledonous pest plants that can destroy a significant part of the crop:
- batachka;
- blackberry;
- rye bonfire;
- foxtail field;
- oats are empty;
- field blouse;
- bluegrass annual, etc.
Among dicotyledonous weeds, the danger to cereals is:
- spurge;
- garden sow thistle;
- porcine fingernail;
- bristle green;
- Chaff perennial and others.
All of these plants should be fought because they greatly affect crop yields. Especially dangerous are already mature, as in the photo, cereal weeds that absorb a large amount of nutrients from cultivated crops.
Growth duration
In addition to differences in their structure, cereal weeds are divided by the life cycle. Some of them appear annually from new grain, while others are able to winter and grow from a preserved root, therefore they are called annual or perennial.
Annual cereal weeds include:
- batachka;
- blackberry;
- rye bonfire;
- foxtail field;
- bluegrass annual;
- blue cornflower;
- spurge.
The following plants are perennial:
- Gum
- wheat grass creeping;
- pasture ryegrass;
- salamalia;
- chaff perennial.
Dicotyledonous annual plants
These weeds are very common and can cause great damage to cultivated plants:
- Blue cornflower. This pest grows mainly in fields with cereal crops. The height of its stem can reach 90 cm, and the flowers have a different color - from blue to dark blue. Active vegetation begins at the end of spring, and flowering lasts from June to autumn frosts. Each flower produces more than 1,000 seeds, the viability of which (in the ground) can reach up to 10 years. Such a cereal weed often does not cause particular problems to cultivated plants.
- Spurge. This weed is quite strong due to a well-developed and strong root. Its stem with elongated leaves can grow up to half a meter. Its first sprouts are observed in late spring and it blooms throughout the summer. Despite the fact that the germination of milkweed seeds is very low, due to their number, the weed appears annually in those places where legumes, grains and forage crops are cultivated. A very serious fight should be waged against this plant, since its uncontrolled growth can lead to the complete seizure of territories with crops.
- Garden sow thistle. Another one-year dicotyledonous cereal weed, which poses a significant threat to crops, as it is quite difficult to control it. The reason for this is its strong and long root, deepening into the ground by two meters. Simply pulling out this weed is often not enough, since part of the processes of the rhizome can remain in the ground, which will lead to the early germination of a new stem.
Perennial dicotyledonous weeds
These weeds have a huge supply of nutrients, so they are able to develop rapidly. The most common of these are the following:
- Pig-fingered. The first seedlings of this plant come from grain, but in subsequent years it grows from a root preserved in the ground. It appears in the areas of crops from mid-spring, blooms in June, and begins to bear fruit from July to September. This plant is thermophilic, therefore its habitat is the southern regions of Russia and Central Asia.
- I spat for many years. This weed prefers to grow on loamy soils rich in nitrogen. Most often found on rapeseed and crops. It multiplies due to elongated root sections that germinate in the spring. Flowering begins in the middle of summer, and in the fall it sheds seeds that can be stored in the soil for up to 4 years.
Monocotyledonous annual weeds
Annual weed grass grows both in the fields and in the gardens. Frequently encountered representatives include: blackberry, batachok, foxtail field, bluegrass annual:
- Batlachok. This pest grows from spring to autumn on soil with a high carbonate content and sufficient moisture. In height, it can reach more than half a meter. The leaves are sharp and narrow, with small grooves. Seeds can remain viable for 10 years. Prefers this cereal weed to grow among winter crops, row crops and oilseeds. Its presence significantly reduces the quality and quantity of the crop, and also complicates the process of harvesting (threshing).
- Blackberry. He likes moist humus, loamy and sandy soils rich in nutrients. The blackberry sprouts in early summer from last year's seeds, which can be in the soil before germination from 3 to 5 years. This plant is rightfully considered the most malicious cereal weed. It enters into serious competition with corn crops, because it grows from May to August. Its active vegetation and a high density of seedlings negatively affect the cereal crop.
- Foxtail field. He chooses the place of growth of carbonate soils, provided with moisture. It grows from the beginning of spring until mid-autumn. On its stem, which reaches 60 cm, there are spikelets with seeds. It spreads on winter crops, row crops and oilseeds. To a large extent affects the quality of the crop and its threshing.
- Bluegrass annual. It grows on nitrogen-containing and well-moistened soil. Seeds are formed on a panicle extending from the stem. For grain crops is not particularly dangerous, but the corn crop is able to reduce.
Monocotyledonous perennials
Monocotyledonous perennial cereal weeds include the following:
- Gumai. It grows mainly on moist nitrogen-containing soils, from spring to late summer. It grows annually from last year's seeds, as well as long root processes. It has a smooth straight stalk with serrated leaves. There is no significant harm from cereals to it.
- Wheat grass creeping. This weed does not have special preferences in the soil, however, it develops more actively on land with a high humus content. It grows from spring to cold autumn. Its stem is straight and smooth with twisted leaves. It spreads on cereal crops and affects the quality of the crop and harvest.
- The ryegrass is grazing. It begins to emerge with the advent of spring on loamy soil. Perennial to this weed is provided by underground side shoots. The stem, covered with dark green leaves, grows up to 50 cm. Despite the fact that it is a valuable pasture plant, it harms the growth of cereals, potatoes and canola.
Methods of struggle
Mechanical and chemical agents can be used to control cereal weeds.
An effective way to eliminate weed grass is to remove the plants along with their root system, using special tools or manually. This method will be most effective during the period when the seeds have not yet ripened in the weeds.
In fields and other large areas, mechanical control of such plants is carried out using special equipment, which is equipped with weeds.
Also, such methods include sheltering the earth with special materials that do not allow light to penetrate. Holes are made in the protective fabric, into which cultivated plants are planted. However, this method is only suitable for gardens, since it is not possible to implement this in the fields.
Chemical methods for controlling cereal weeds involve the use of special herbicides, which, when penetrated into the soil, destroy the root system of weeds, as well as their seeds.
All funds are divided into two groups: soil and post-emergence. The use of the first herbicides is possible only at a time when there are no crops and plantings in the soil. Such funds, falling into the ground, kill weed seeds before they germinate. Post-emergence cultivate the soil after the emergence of crops. They are more complex in composition, as their action is selectively directed. Herbicides destroy harmful plants, and crops do not exert any effect.