Weeds are propagated with the help of special devices. Weed plants. Weeds and their importance in agriculture
The widest distribution of weeds is primarily due to their enormous fertility. While, for example, one cereal plant, even with the best cultivation, is capable of producing on average only about 2000 grains, the fertility of most weeds is immeasurably higher, as can be seen from the following data showing how many seeds or fruits it produces one weed.
Further, weeds are endowed with special and varied adaptations for dispersing their seeds over as wide a space as possible.
One plant produces fruits or seeds
Rye brome (Oromus secalinus)....... 1 420
Doll (Agroslemma githago)......... 2 500
Gray mice (Selaria glauca) ........ 5 520
Cornflower (Centaurea Cyanus/....... 6680
Buckwheat (Polygonum convolvj/us L.) 11 200
White Dawn (Lychnis alba) ......... 14690
Field sow thistle (Sonchus arvensis)....... 19000
Krgstovnik is ordinary. (Senecio vulgar is) ... 20,000
Common flaxseed. (Linaria vulgaris)..... 32 300
Budyak (Cirsium aruense)........... 35 550
Mullein (Verbascum lychnitis)......... 40 000
Odorless chamomile (Matricaria in odor a) .... 54000
Shepherd's purse (Capsella bursa pastoris/ .... 73 OEE
White quinoa (Chenopodium album) ...... 100000
Wormwood (Artemisia Absinthium) .... 102000
Chernobyl (A. vulgaris).......... 143000
Shnritsa (Amarantus retroflexus) ........ 500 000
Walker (Sisymbrium Sophia)........ 730 OEE
In some weeds, this dispersal is achieved by a special arrangement of their fruits, which scatter seeds, as, for example, in peas, etc.; in wild oats, due to twisting and unwinding of awns, from changes in air humidity, grains can not only crawl, but even burrow into the ground. It is known how strongly the grains of wild oat are stuffed into the corners of the sacks or into parts of the machines, and from here they can also fall into other grain, poured into the same sacks or cleaned on the same machines.
At the same time, weed seeds can be carried by water, wind, animals, etc.
With the help of water, weed seeds can not only spread over the surface of the earth, as, for example, during rains in hilly areas, but also penetrate deep into the soil, when, for example, after a severe drought that forms many cracks in the ground, heavy rains come . In irrigated areas, weed seeds and even whole parts of plants are dispersed by irrigation water.
First of all, the wind can roll over the surface of the earth not only individual fruits and seeds, but even entire bushes of weeds, forming the so-called. "tumbleweed", as it is observed in our steppe regions, where, picked up by the wind, numerous bushes of kurai, kachima and many others rush through the fields in autumn. All this usually accumulates near any obstacles encountered on the way, near ditches, hedges, in ravines, etc. That is why the borders and various other abandoned places differ among us in many weeds.
Even more often, the fruits or seeds of weeds are picked up by the wind and carried through the air, due to the lightness of the seeds, or due to the various hairs and tufts that are provided, for example, with achenes:
sow thistles, budyakov. dandelion and more etc. All these flying seeds at the same time stick to the dress, ...
High fertility.Most of the weeds have an increased ability to reproduce. According to acad. A.I. Maltsev, some weeds are capable of producing a huge amount of seeds. If in crops one plant of winter rye is able to form 120â?”200 grains, fiber flax â?” 60â?”100 seeds, then one rye brome plant can produce 1420 seeds, blue cornflower â?” 6820, thistle field â?” 19 thousand, odorless chamomile â?” 54 thousand, mari white up to 100 thousand seeds, curing up to 200, and one well-developed plant of upturned amaranth can produce up to 500, striated goluvka up to 730 thousand. According to seed productivity, all young weeds are divided into 3 groups. The first group includes weeds that form on average from 50 to 600, up to a maximum of 15 thousand seeds. These are common cockle, gray foxtail, wild radish, bindweed mountaineer, etc. In height, they are plants of the middle tier. The second group consists of weeds that give an average of 600 to 1500 seeds with a maximum productivity of up to 100 thousand seeds. These include field yarutka, field mustard, shepherd's purse, gray hiccup, etc. The third group includes weeds, the average fertility of which is from 1.5 to 5 thousand seeds, and the maximum is up to 1 million seeds. This includes black henbane, white gauze, upturned amaranth, Canadian small-flowered, etc.
However, their fertility depends on the growing conditions. Weeds reach the highest fertility on fertile lands in cultivated crops, along roads, irrigation canals, and on uncultivated lands with good moisture, light, temperature and food conditions. Late weeds develop well in row crops.
Unfriendly seed germination and uneven ripening. Weed shoots appear from early spring to late autumn. This is facilitated by various temperature and light conditions, varying degrees of soil moisture, seed diversity (the phenomenon of heterocaria). Weeds such as common wild oats, white gauze, bindweed herb, etc. in early spring sprout in early May, and in a cold long spring - in the second half of May. Seedlings of more heat-loving weeds (chicken millet, upturned amaranth, gray foxtail) appear in late May - early June, and the seeds of winter weeds germinate only in the second half of summer. The extended period of seed germination is explained not only by their different attitude to external conditions, but also by the polymorphism of the seeds. For example, on one plant of white mari there are three types of seeds: large, medium and small. Some of them (large ones) germinate in the year of maturation, others (medium ones) - in the second year, and small ones in the third year and later.
Acad. A.I. Based on a review of works by a number of authors, Maltsev concludes that for the seeds of most weed species, the optimal depth for seed germination is 0-5 cm, for some species - up to 10 cm. Above 10 cm, most species do not germinate, as they usually have small seeds.
V.P. Tomilov found that the greatest number of seedlings of wild oat was obtained at a seeding depth of 5-10 cm. Seedlings from seeds embedded deeper than 20 cm did not break through to the surface.
Field germination of small-seeded weeds depends very much on the depth of incorporation. According to N.Z. Milashchenko and I.N. The cousin from a depth of 3-5 cm gave rise to 67.2-66.5% of the foxtail seeds, from a depth of more than 5 cm, the seedlings did not reach the surface and all died. Shoots of weeds from a depth of 10-15 cm appear with a great delay and look more weakened, oppressed.
Ways to spread weeds Weeds are spread most often by seeds and less often by vegetative organs. Ripened seeds are scattered during the rocking of plants by the wind, when mowing, sharp cracking of fruits, moving the mowed mass of weeds. Spherical bushes of some weeds (saltwort, stag, white amaranth, eryngium) cut off from the ground after the seeds ripen roll across the field with the wind, the seeds stick with mud to shoes, animal hooves, wheels Vehicle. The resettlement of weeds can also occur with poor cleaning of the working bodies of machines, with poorly cleaned seed material, unripe manure and bird droppings. The presence of various adaptations in seeds allows them to spread over considerable distances (Fig. 4). The spread of seeds and fruits of weeds is carried out either with the help of special devices in plants â?” autohorn, or with the help of various agents â?” aplohorno. In autochora plants, the dispersion of seed primordia occurs with the help of various devices, driven by mechanical forces. So, in field mustard, field cabbage, wild radish, levkoy icterus, odorless chamomile, seeds and fruits are scattered around mother plants under the influence of gravity â?” autobarochornally. Mechanical scattering of seeds, due to the tension that occurs in the drying integumentary tissues of fruits, is observed in the cicuta stork, field violet, narrow-leaved pea and other weeds. With the help of wind â?” anemochornoâ?” Seeds of common dandelion, wild boletus, common ragwort, small-flowered canadian and many other weeds from the Compositae family are spreading. They are equipped with feathery bats, thanks to which they can be transferred to the surrounding fields and distant territories even with a weak wind (Fig. 4). The seeds of thistle, dandelion are equipped with bats, with the help of which they are carried by the wind. Seeds and berries of many weeds are spread with the help of animals, birds, insects, i.e. zoochory. Fruits or inflorescences of Velcro blackberry, with the help of which they cling to animal hair, human clothing, bird feathers and are transferred to neighboring fields and new habitats.
Vegetative propagation of perennial weeds. In the soil, along with seed primordia, there are also roots of perennial weeds (rhizomes, bulbs, nodules, etc.), capable of vegetative propagation and called breeding roots. The high ecological plasticity of these weeds is determined both by the quantitative abundance and the high regenerative ability of the propagation roots. In many of them, a significant part of such roots is also located in the subsurface layer, often penetrating to a depth of 1–2 m or more. As a result, a large part of the root system is inaccessible to soil-cultivating tools, the working depth of which usually does not exceed the thickness of the arable layer. In the roots of reproduction are stored plastic substances in the form of carbohydrates, the content of which, depending on the type of plant and the growing season, ranges from 5â?”12 to 35â?”54 %. They form a large number of adventitious (adnexal) kidneys. When the roots are damaged by tillage tools, some of these buds awaken and form new plants instead of the destroyed ones. During processing, the propagation roots in the arable layer are torn and crushed into fragments. various lengths. Under favorable conditions, these segments are able to take root and even form independent plants. The reproduction roots of field sow thistle, couch grass, Tatar lettuce, field horsetail are characterized by high survival rate, while the survival rate of such roots in creeping mustard, field thistle, field bindweed is very weakly expressed.
With a decrease in the size of root segments, their ability to regenerate decreases. Nevertheless, the propagation roots of a number of perennial weeds (field sow thistle, couch grass, etc.) are capable of regeneration even with a fragment length of 1–5 cm.
Moreover, strong crushing of the roots of perennial weeds stimulates the awakening of a large number of adventitious buds on their segments. As a result, the regenerative capacity (determined by the number of shoots formed per 1 m2) of propagation roots increases by 1.5–2 times or more.
Therefore, occasionally held in clean couple tillage or careless inter-row cultivation of row crops leads to a strong overgrowth of these fields with weeds.
With a decrease in the length of the roots of reproduction, and, consequently, with a decrease in the reserves of plastic substances, their survival rate decreases sharply. Therefore, the crushing of the roots and their subsequent embedding into the soil to a depth of at least 20–25 cm almost completely exclude the regeneration of perennial weeds from the arable layer from segments of their propagation roots. This is the basis for the mechanical destruction of perennial weeds, called suffocation method. With minimal and zero technologies, to destroy such weeds, one has to resort to chemical methods of control.
The survival rate of fragments of propagation roots sharply decreases with an increase in soil density (above 1.1 g/cm3), a decrease in soil moisture (below 15–20%) and temperature (below 5–10 °C).
High ecological plasticity is observed in perennial weeds and in unfavorable periods of their life. With deep mechanical damage to the roots, excessive soil compaction, prolonged drought, the root system of creeping mustard, wild thistle, field thistle, Tatar lettuce, and horsetail falls into a dormant state for 2–3 years. With the onset favorable conditions the preserved part of the root system resumes the regeneration of underground offspring, from which full-fledged plants are then formed. This explains the often unexpectedly abundant appearance of perennials on plowed fields, the presence of which in crops in previous years was practically not observed.
All this determines the high viability and stability of perennial weeds, if they are controlled without taking into account their biological and ecological characteristics.
Seed longevity. If cultivated plants, in particular cereals, seeds during storage remain viable for up to 5 ... 10 years, then for most weeds, once in the soil, they are viable for several decades. Due to the hard shell, the seeds long time remain viable, regardless of soil moisture. Shell hardness is a biological property that is inherited. This property is most characteristic of some species of the legume and mallow families. With mechanical damage to the waterproof shell, seed germination is accelerated.
The longevity of seeds is also explained by the presence of dormancy. For example, wild oat seeds remain viable for 4-5 years, white mari - 20, field mustard - 7 years, wood lice - 10-15 years.
Distinguish between deep and forced rest. The first is related to the physiological state of the seed and the structure of the shell. The second is due to unfavorable external conditions(lack of moisture, air, heat, light). The destruction of seed coats contributes to their faster exit from dormancy.
Biological and forced dormancy of seeds. One of the characteristic features of most weeds is â?” unfriendly seed germination. If their seeds germinated as amicably as in cultivated plants, then it would be much easier to deal with them. The main reason for unfriendly germination is â?” the presence of a period of biological rest, when physiological and biochemical processes are weakened. Such a period in the life cycle of seeds is determined by a number of reasons: water and air impermeability of seed coats, high osmotic pressure of cell sap in seed coats; physiological immaturity of the embryo; the presence in different parts of the seed of inhibitory substances, the so-called inhibitors, which delay its germination; the isolation of protoplasm, the elements of which have not yet been included in the metabolism of the whole organism. From a general biological point of view, the dormant period of weed seeds is a way of adapting the body to maintain viability in adverse conditions, one of the ways of self-regulation of life processes in the body. A long dormant period in weed seeds is especially great importance to save the look.
The rest period can be broken under the influence of light, variable temperatures, high frequency currents, mechanical or chemical destruction of the shell. In order to bring viable weed seeds out of the dormant period, it is necessary first of all to provide air, heat and water access to the embryo and reserve nutrients. Some factors (frost, periodic changes in temperature and changes in the humidity of the environment) open access to air, heat and water, since under their influence the permeability of the seed coat increases. Frost has an effect only on the wet shell, because it increases the activity of enzymatic processes in swollen seeds. The favorable effect of the alternation of frosts and thaws in winter periodâ?” one of the most important reasons high energy germination of weed seeds wintering in the soil in spring. Frost has little effect on dry seeds, so in spring they germinate slowly and in smaller numbers.
In addition, there is a forced rest. Compelled(secondary or ecological) peace in seeds and fruits, it is usually caused by the absence of a favorable combination of external environmental factors that promote their germination (lack of moisture, excess heat, lack of light, the presence of plant inhibitors produced by other species, etc.). Unlike cultivated plants, the seeds of which must have a high germination rate, weed seeds have a very extended germination period. The prolongation of the germination period is also preserved in weed seeds that are constantly in the soil.
Many of the weed fruits that have fallen into the soil find themselves in unfavorable conditions and die. A significant part of the remaining fruits is able to remain viable in the soil for a long time and this causes clogging of crops of subsequent crops for several years to come.
Seeds of most cultivated plants usually remain viable for no more than 4–7 years and if stored indoors under optimal conditions. The seeds and fruits of many weeds do not lose their viability even after many years of being in the soil.
The unusual longevity of weed seeds is evidenced by the data of an experiment established by W. Bill as early as 1879. at Michigan College (USA). It has been established that the seeds of medium stellate, field mustard, shepherd's purse, upturned amaranth, yellow sweet clover remained viable after 30 years of burial in the soil, and the seeds of field bindweed, curly sorrel, black mustard did not lose their germination capacity even after 50 years under these conditions.
Diversity. In some weed species, seeds or fruits formed in one inflorescence differ in morphological and physiological characteristics. (diversity, or heterocarp). This increases the ability of the species to establish itself in the developed territory and to be introduced into new agrophytocenoses. So, in white mari, seeds of three types are formed: large, flat, greenish-brown light tones, which germinate in autumn in the year of formation; medium in size, round-convex, with a thin shell, greenish-black germinate in the second year; very small, round-oval, thick black germinate usually in the third year and later. In the wild oat panicle at the ends of the branches, spikelets are formed with grains of different types according to biological characteristics. In the upper part of the spikelet, small dark-colored grains are formed, easily crumbling, their dormant period is up to 16–22 months. They form seedlings from a depth of no more than 10–12 cm, and the plants are similar in rhythm of development to late spring ones. The grains from the lower part of the spikelet are the largest, light-colored, crumble later and therefore clog the seed of the crop. The rest period of these grains is about two to three months, at the end of which they sprout together under favorable conditions, giving seedlings from a depth of 18–25 cm, and develop as early ripening plants. In the middle part of the panicle, grains are formed that are intermediate in morphological and biological characteristics.
In weeds from the aster family (compositae) (spring ragwort, large goat-beard, etc.), seeds that form at the center of the inflorescence (basket) have a shorter dormant period than those located at the edge.
Different-time ripening of seeds and fruits. In the process of natural selection, young weeds have developed the ability to finish life cycle somewhat earlier than in cultivated plants. This leads to the fact that already in advance (before optimal time crop harvesting), a significant part of the weed seeds formed on plants crumble to the soil. In addition, it excludes the possibility of directly removing these seeds from the field, as is easily possible with weed seeds that fall, for example, into the bunker of a combine when threshing grain crops.
So, in the crops of winter crops, one and a half to two weeks before they are threshed, the plants of wild radish, shepherd's bag, field yarut completely die off, and a large proportion of their seeds fall into the soil. A few days later, the seeds of odorless chamomile, blue cornflower, field larkspur, rye bonfire, field broom, etc., already ripened on separate branches, begin to crumble onto the soil. The period of grain ripening in wild oats is very extended, and by the phase of full ripeness of wheat, when they start threshing the crop, almost half of the seeds formed entered the soil.
In the steppe regions of Russia, some weeds, such as barnyard grass, cockerel millet, gray bristles, upturned amaranth, Russian saltwort, are strongly suppressed in grain crops and almost do not form seeds. However, after the threshing of grain crops and with favorable nutritional and water regimes in the unshaved stubble and a short daylight hours they rapidly go through the life cycle and after 2â?”3 weeks form an additional 40â?” 60 million seeds per 1 ha, replenishing the stocks of weed diaspores in the soil. These weeds are called stubble.
Numerous studies have established that in the arable layer of soil in individual fields there are seeds of 10â??25 different types of weeds, with a total number of 120 million to 3â?? 4 billion per 1 ha.
Considering the huge potential stock of seeds and fruits of weeds in the soil, it is necessary to conduct systematic weed control. This is one of the most urgent tasks in agriculture in the near future.
Other biological features. In some weeds, the seeds do not lose viability after passing through the intestines of animals and birds, for example, small seeds that are not mechanically damaged by ruminants or are completely eaten by various birds. The seeds of some weeds are not destroyed after processing cereal crops or grinding grain into flour, especially with coarse grinding.
There is a group of weeds that are characterized by diversity (heterocarpy), and this feature is hereditary. These include white gauze, wild oat, brilliant quinoa (has three types of seeds), ragweed wormwood (six), medicinal dandelion (two), millet, bird knotweed, ragwort, etc. These seeds differ in size and color, have a different period of biological dormancy, their germination is different, despite the fact that they were formed on the same plant or even inflorescence.
Some weeds are characterized by mimicry, i.e., the external similarity of their or individual organs, in particular seeds, with cultivated plants. This biological feature makes it possible to easily spread with seed. To separate such weed impurities, cleaning is required on special grain cleaning machines.
Biological features of weeds and their distribution
The greatest efficiency in weed control can be achieved by knowing their biological characteristics and distribution conditions. Many weeds, constantly growing in the same crops, have acquired morphological and biological characteristics similar to cultivated plants, which greatly complicates their extermination. For example, in the crops of spring crops, spring weeds are found due to the similarity in their development, and in the crops of winter crops, winter and wintering weeds are found.
weed plants less demanding than cultural ones. They are more cold hardy and drought tolerant. In addition, weeds reproduce very well. For example, wild radish can produce up to 12 thousand seeds, field sow thistle - up to 19 thousand, pink thistle - up to 35 thousand, shepherd's purse - up to 70 thousand, amaranth - up to 500 thousand, while grain crops produce an average of 100 grains with one plant.
Seeds of many weeds are able to be stored for a long time, and then sprout. For example, the seeds of such weeds as amaranth, shepherd's purse, wood lice and some others retain their viability for 10–15 years, being at rest, mustard - 7 years, field yaruka and plantain - 9 years.
Weed control is difficult because of the unevenness of their seedlings. Germination of their seeds can continue for a long time. For example, one quinoa plant produces three types of seeds, the first of which germinate in the year of ripening, the second - the next spring, and the third - only in the third year after they crumble. Such non-simultaneous germination of weed seeds is explained by the fact that the seed coats unevenly transmit moisture. Some types of weeds, in addition to propagation by seeds, are able to propagate vegetatively, i.e., rhizomes, root shoots, above-ground layering from stems, bulb segments, etc. The reproduction of weeds is also facilitated by the fact that they easily crumble, are freely carried by the wind to large territories, as well as the fact that many animals are involved in seed dispersal. Many weed seeds are brought to agricultural areas by melt water. The breeding grounds for weeds are uncultivated areas, roadsides, railroad tracks, etc.
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The biological characteristics of weeds are very diverse. Many weeds have a very high multiplication rate.
So, one white amaranth plant can produce up to 6 million seeds. The high fertility of weeds leads to the fact that up to 800 million or more viable weed seeds per 1 ha are concentrated in the arable soil layer, while a person sows, for example, 4-6 million seeds of grain crops. The multiplication factor of some representatives of weeds can be judged from the data of A. I. Maltsev, S. A. Kott and other researchers, given in Table. 12.
The fertility of weeds is tens and hundreds of times higher than the fertility of cultivated plants.. The high multiplication factor of weeds provides them with successful competition in the struggle for existence.
Features of weed seeds are: the ability to not lose germination for a long time, unfriendly germination, extended dormant period. Numerous experiments indicate that the seeds of many weeds, being in the soil at great depths, may not lose their viability for a long time.
Some weeds form groups of seeds, to varying degrees prepared for germination. So, white mari has seeds of three groups: 1) large brown, germinating in the first days of seeding; 2) smaller ones with a thick shell of black or greenish-dark color, germinating in the second year; 3) very small, almost round, shiny, black, germinating in the third year.
Seeds of many weeds are difficult to separate from the seeds of cultivated plants, for example: chaff seeds - from wheat seeds, rye rump - from rye, wild oat - from oats, clover dodder - from clover, etc. As a result, when cleaning the seed material, they remain not isolated from the seeds of a cultivated plant and are brought to the fields during sowing .
Seeds of some weeds, having passed through the animal's gastrointestinal tract with food, do not lose their viability and, having fallen on the fields along with unrotted manure, give new generations.
The seeds and fruits of many types of weeds have adaptations for carrying them over long distances. So, in a dandelion, thistles, the seeds are equipped with flyers, parachutes, with the help of which they rise high into the air and are carried by the wind over long distances.
Seeds of such weeds as burdock, Velcro have hooks, hooks with which they are attached to containers, human clothing, animal hair and spread across the fields. In the process of barter at the end of the last century, white amaranth was brought to us from the United States, which became widespread as an annoying weed in Krasnodar Territory, Rostov region and in many steppe and forest-steppe regions of Ukraine.
Weeds as representatives of wild flora in the process of long evolution in the struggle for existence have acquired many different properties and adaptations to different ecological regimes. They are distinguished by great frost resistance, the ability to tolerate drought, lower temperatures during the growing season, etc.
Weed seeds germinate best when they are shallowly planted (0.5-5 cm). This feature should be taken into account in order to provoke them to germination and subsequent destruction by methods of tillage.
Many perennial weeds have a high ability of vegetative reproduction..
The ability to simultaneously abundantly form reproductive organs (seeds and vegetative buds) is a great obstacle to the destruction of perennial weeds: rhizomatous (wheatgrass, pinworm, pigtail, field horsetail, etc.), root weeds (pink thistle, yellow thistle, mustard, rape, etc.) . For example, the amount of seeds obtained from a clump of 1 m2 occupied by pink thistle can completely inseminate and clog an area of 10 hectares, and a 15-day-old seedling of field thistle (yellow) can form new offspring when it is cut.
Sow thistle (yellow, pink), couch grass with their powerfully growing root systems greatly dry out the soil, and pink mustard root systems release substances harmful to many plants, and grain crops die near its clumps. It is very common in the Central Asian countries, in the Caspian steppes, in the south of Ukraine.
WEEDS, CLASSIFICATION AND MEASURES FOR THEIR CONTROL
1. Harm and harmfulness of weeds
2. Biological features of weeds
Weeds are called such plants that are not cultivated by man, but clog crops with. - x. crops and other areas.
Weeds - plants that are cultivated species, but not cultivated in this field and infesting crops of the main crop.
In the production of varietal seeds, weeds include all plants of the same species that do not belong to this variety.
Some weeds are so adapted to the living conditions of cultivated plants that they exist as their companions. These weeds are called specialized.
Weeds are highly resistant and adaptable, developing properties similar to those of cultivated plants: winteriness, springiness, height of stems, and the ability to behave like annual forms.
1.1 Harm caused by weeds
Harm is the damage caused by weeds to crops. It consists in a shortage of crops and a decrease in the quality of agricultural products.
Yield losses caused by weeds are large. On a global scale, they are estimated at 20.4 billion dollars, which is 14.5% of the crop.
Weeds complicate and complicate the care of cultivated plants, reduce the productivity of agricultural crops. machines and implements, resulting in a deterioration in the quality of work in agriculture, and an increase in fuel consumption. The clogging of irrigation canals leads to huge water losses and increased swimming.
Harm from weeds is expressed, first of all, in the inhibition of the growth and development of cultivated plants, as a result of which the yield decreases, its quality deteriorates. This is due to a number of reasons. Many weeds consume 5-7 times more nutrients than cultivated plants.
From the very beginning of the growing season, many weeds outstrip cultivated plants in growth and shade them heavily.
Quite varied and indirect Negative influence weeds on cultivated plants.
Many of them serve as the center of distribution of wreckers and diseases of page - x. plants. Pests often appear first on wild and weed plants, and then move on to cultivated plants.
The influence of weeds on cultivated plants reflect the thresholds of weed damage
Phytocenotic threshold of harmfulness (FPV)- the number of weeds at which they do not cause damage to cultivated plants.
Critical Harm Threshold (CPV)- such an abundance of weeds that causes statistically insignificant yield losses. Under such conditions, losses do not exceed 3-6% of the actual yield, and weed control is not advisable.
Economic threshold of harmfulness - (EPV)- the level of contamination at which, under specific conditions, the use of herbicides is economically justified.
The economic thresholds of weed damage should be included in the lists of chemical plant protection products permitted for use in agriculture as one of the mandatory regulations for the economic justification of the use of herbicides.
In order to implement a rational system of weed control, it is necessary to know about the phases and periods of high sensitivity of crops to weeds growing in crops. The duration of the period during which cultivated plants react negatively to weeds is called herbacritical.
To obtain the maximum crop yield with minimal control costs, it is necessary to destroy weeds in crops by the beginning of the herbacritical period.
Carrying out extermination measures within these periods gives the maximum effect.
After the culture enters the herbacritical period, weed control measures give a smaller economic effect.
2. BIOLOGICAL CHARACTERISTICS OF WEEDS
Biological features include: fertility, methods of distribution, biological dormancy of seeds, longevity, vegetative propagation
Fertility
The widest and fastest spread of weeds is facilitated, first of all, by the abundance of their seeds and fruits. Whereas, for example, a single cereal plant, under the best field conditions, can produce only about 2,000 grains on average, the fertility of most weeds is much higher.
Depending on fertility, all weeds are divided into three groups:
The first group is weeds that make up the middle tier in crops; they are capable of producing from one to 15 thousand seeds.
The second group is weeds that produce up to 100 thousand seeds and belong to the upper and lower tiers in crops, that is, they spread independently.
Distribution methods
Weeds have a wide variety of adaptations for dispersing seeds over as large a space as possible.
The distribution of seeds and fruits of weeds is carried out with the help of special devices - autohorn, or with different agents - hello-horno.
autochoir seed dispersal can be carried out using various mechanical forces. So, field mustard, wild radish, odorless chamomile seeds scatter around mother plant under the influence of gravity. Mechanical scattering of seeds is carried out due to the drying of the fruit valves (field violet, narrow-leaved peas, etc.) and boxes (common cockle, field mustard, self-seed poppy, black henbane, etc.
The common cockle has an upright box and the seeds are poured out in parts as the stem is shaken and bent by the wind.
Animals spread weeds (zoochory) already due to the fact that the seeds they take as food, usually with food, are not always digested and go outside without losing their germination, and together with manure fall into the field
The seeds of many species of weeds have special outgrowths in the form of anchors, hooks, serrated spines, bristles, awns, with which they cling to animal hair and bird feathers. These include blackberry Velcro, common dope, tenacious bedstraw, large burdock, gumai, round syt, wild oat, common barnyard, types of fires, goiter cocklebur
A person can create a number of conditions conducive to the spread of weeds.
Insufficiently thoroughly cleaned seed, lack of proper crop rotation and tillage, misuse fertilizers, all this indirectly contributes to an increase in weed infestation of agricultural crops. cultures.
Many weeds are introduced by humans from one country to another. It is obvious that in this way the Canadian small-flowered, fragrant chamomile, introduced in the 40s, white amaranth, which appeared in the 80s of the last century, clover dodder, discovered in 1915, came to us from America in this way. All of these species show extreme rapidity of distribution.
Biological dormancy of seeds.
Under "peace" understand the lack of germination of a viable seed in the presence of favorable conditions (water, oxygen, temperature). Seed dormancy is an important adaptive property that allows plants to bypass unfavorable periods of the year. In this regard, a reserve of seeds is created in the soil, which contributes to the preservation of the species. ^ There is natural and forced rest.
Natural or organic dormancy is associated with the properties of the seed itself: underdevelopment of the embryo, hard seed, air and water resistance of the peel and integuments, the action of inhibitors, etc.), as well as the incompleteness of physiological and biochemical processes in the seeds.
Forced rest- non-germination of seeds in the absence of the necessary conditions (moisture, temperature, light, etc.)
The dormancy period is disturbed under the influence of variable temperatures, magnetic and gamma fields, ultrasound, mechanical disturbance of the seed coat as a result of tillage.
Seed longevity
In the absence of favorable conditions for germination, the seeds of cultivated plants lose their germination capacity in a short period. The seeds of weeds retain their germination for a long time in soil, water, silage, manure, compost.
Longevity is understood as the ability of seeds to maintain life in certain narrow conditions.
The longevity of seeds is affected by their degree of maturity, place of growth, agricultural background, method of harvesting and storage, composition of seeds, property of the shell and processes taking place in the seeds. Seed longevity is hereditary. Illumination is also of considerable importance. In the vast majority of cases, germination can take place in complete darkness, but for the seeds of cereal weeds, light is essential. Seeds of white mistletoe, mullein germinate more actively when illuminated.
On the other hand, there are a number of plants whose seeds do not germinate at all in the light, such as dodder species.
Vegetative propagation of weeds.
In addition to seed, many weeds have a pronounced ability for vegetative reproduction with the help of underground organs - root offspring. , rhizomes, bulbs and tubers, as well as with the help of above-ground stem organs. The most malicious are perennial root-weeds (creeping mustard, various types of thistle, field bindweed, etc.) and rhizomatous weeds (creeping couch grass, pig fingered, gumai). In the roots of reproduction, plastic substances are deposited in the form of carbohydrates, their content varies depending on the type of plant and the growing season and ranges from 5-12 to 35-54%.
3. Classification of weeds
On the territory of Russia there are more than 1000 species of weeds, including about 400 species of poisonous ones. To facilitate the study and fight against them, weeds were classified, that is, grouped into groups according to similar living conditions. The classification is based on the following features:
Method of plant nutrition;
life expectancy;
method of reproduction;
According to the method of nutrition, weeds are divided into types:
host plant to which they attach.
Types are divided into subtypes by life expectancy
Juveniles: annuals and biennials;
perennial
Annuals have a life cycle of one year, biennials require two growing seasons. Perennials grow in one place for several years.
Annuals are divided into biological groups:
Ephemera;
Wintering (annual dicots);
Spring early;
Late spring (dicotyledonous, monocotyledonous)
Biological groups are determined by similar periods of germination, duration of vegetation and maturation.
Biological groups in the perennial subtype are determined by the development of the root system and its type
Taproot;
Fibrous;
Bulbous;
Rhizome;
root shoots;
There are special weeds that have a developmental biology similar to cultural biology: in terms of germination time, mode and life expectancy, etc. d.
There are hard-to-separate weeds - the mass of their seeds, shape and size are close to the clogged crop. These include: wild oat, Tatar buckwheat, rye bonfire.
Classification of weed control measures
The classification of weed control measures is based on two features (A. M. Tulikov)
1. By the type of object to which this or that technique or method is directed. Weeds, their seeds, fruits, rhizomes, shoots, etc.
2. By the type of means by which weeds and sources of their distribution are destroyed.
According to the first sign, they distinguish agrotechnical method of struggle, which is divided into preventive, extermination and quarantine measures.
According to the second feature, physical, mechanical, chemical, biological, phytocenotic, ecological, organizational and complex ones are distinguished.
Warning- measures to prevent the penetration of weeds into the fields. These include:
Seed cleaning. To avoid getting weed seeds,
kov with seeds of cultivated plants in the field, they are thoroughly cleaned
on grain cleaning machines, units and complexes;
timely and proper cleaning harvest. With timely
When harvesting by direct combining of cereals, seeds and fruits of weeds crumble less than during two-phase harvesting. In this case, the main mass of weed seeds enters the harvester bunker, and only a smaller part enters the soil;
High-quality preparation of animal feed involves steaming chaff, straw, grain waste;
Proper storage of manure. Eaten with feed and passing through the digestive tract of animals, weed seeds can remain viable for a long time. With a loose method of storing manure, the viability of seeds is reduced. Composting manure with peat or phosphate rock also reduces the germination of weed seeds.
Certain quarantine measures carried out on a national scale. These include antiweed quarantine, the purpose of which is to prevent the importation of weed seeds from other countries that are not in our country ( external quarantine) or preventing the spread of dangerous weeds from one area to another ( internal quarantine). A special service has been organized that controls the seeds of agricultural crops coming from abroad or from one region to another. crops and other goods with which weed seeds can be imported.
Seed material with quarantine weeds is not allowed for transportation or sowing. A list of typical weeds for each area is available from the Quarantine Inspectorate.
Fighting activities aimed at the direct destruction of seed and vegetative primordia in the soil, as well as vegetative weeds.
It is possible to destroy the reserves of viable seeds in the soil pro methodvocations and deep embedding. Its essence lies in the fact that during the absence of cultivated plants on the field, favorable conditions are created for the germination of seeds, and after the emergence of seedlings, they are destroyed by one or another method of tillage.
On the territory of the Stavropol Territory provocation method they are used 2-3 times after harvesting annual legume-cereal mixtures for green fodder, winter cereals, spring barley, peas and corn for silage in the system of basic and pre-sowing tillage. As the first method, post-harvest stubbing is widely used, which crushes plant residues and destroys weeds from the late spring group, preventing them from seeding. The depth of peeling depends on the climatic zone of our region, in arid regions it should be 6-8 cm. When moving to zones of sufficient and excessive moisture, the depth of peeling increases and reaches 10-12 cm.
The effectiveness of the provocation method lies in the constant destruction of weeds as they appear. This is achieved through cultivation.
Mechanical removal- it is used to clean the soil from rhizomes with great strength (pig, wheatgrass, etc.). The rhizomes located in the upper layer are removed from the soil with spring or rod cultivators and harrows, along and across. Then the extracted rhizomes are collected and burned.
Depletion method consists in the fact that by repeated pruning of the above-ground organs of weeds, the reserves of plastic substances in the roots and rhizomes are depleted, due to which they multiply vegetatively. At the same time, allowing weeds to germinate, replenishment and
accumulation of plastic substances due to photosynthesis. In the system of autumn
Works use 2-3 peelings with increasing depth and deep plowing.
Strangulation method consists in crushing the roots and rhizomes into as small pieces as possible by means of appropriate processing. The crushed segments more quickly consume the plastic substances accumulated in them and the furrows closed to the bottom by deep plowing with plows with skimmers die.
Drying- the use of exposure to sunlight on pre-crushed rhizomes of weeds during steam or early autumn processing. Rhizomes are placed closer to the soil surface by appropriate methods, where they dry out after 15-30 days.
Freezing- consists in extracting perennial weeds to the soil surface during deep plowing of underground organs in late autumn, in order to lose their viability when exposed to low temperatures. It is used in areas with little snow frosty winters.
Under species control means the suppression or destruction of weeds with the help of insects, mites, nematodes, bacteria, fungi, viruses for which the affected plant serves as a source of nutrition. This method has an advantage in terms of environmental protection, because it allows you to destroy weeds without the use of chemical plant protection products.
A classic example of the use of insects for weed control is ragweed leaf beetle, imported from Canada. The beetle has been acclimatized in 10 areas Stavropol Territory, including in Shpakovsky, Trunovsky, Kochubeevsky, Krasnogvardeysky, Ipatovsky and Petrovsky.
Phytocenotic measures control measures are developed on the basis of studying the relationship between cultivated and weed plants in agrophytocenosis.
Direct or contact influence between plants agrophytocenosis is expressed in the following forms:
Competition - the struggle of cultivated and weed plants for the use of life factors. Cultivated plants, being the dominants of agrophytocenosis, have the highest productivity, and, consequently, greater competitive ability. Moreover, continuous sowing crops have a greater competitive ability than tilled crops.
CHEMICAL MEASURES FOR WEED CONTROL
Along with agrotechnical measures, the use of chemicals - herbicides is now widespread. As early as the end of the 19th century, copper sulfate, sulfuric acid, sodium nitrate, calcium cyanamide and other substances began to be used for this purpose. These chemicals are called herbicides (from Latin words herba - grass and ceado - to kill)
herbicides- chemicals used for the destruction of weeds in agricultural crops. cultures.
However, at that time they were not widely used due to insufficient selective action and high consumption per unit area, and some of these substances were poisonous to humans.
Feature of currently used chemicals in that they are in their own way chemical composition and structure are close to the elements of protoplasm or other important metabolic products of plants. Such drugs freely penetrate into plant tissues, disrupt normal physiological processes and lead to their death.
ACTION OF HERBICIDES ON PLANTS
Herbicides are selective, that is, they are toxic to certain groups of weeds. It depends on the differences in the morphology and anatomy of monocots and dicots.
Dicotyledonous plants are more susceptible to herbicides due to the fact that they have an open growing point at the top of the stem, large, horizontal leaves, which in most cases are not covered with a wax coating. This promotes better penetration of herbicides into the plant. In dicotyledonous plants, secondary tissues, which cause an increase in the thickness of the stem and root, arise due to the continuous formation of new cells from the combial layer and cause an increase in cell division, which absorb a huge amount of nutrients for their growth, which leads to disruption of physiological processes, rupture vascular system, stopping the supply of nutrients and water to the leaves. As a result, growth stops and the plant dies. Preparations from the 2.4D group are quite effective in the fight against dicotyledonous weeds. They act on the physiological processes occurring in plants as growth substances.
In grass weeds in the early phases, the growth point is hidden in the leaf sheath, leaf blade narrow, has a wax coating and is located almost vertically in relation to the ground. The herbicide solution almost does not remain on the surface and does not penetrate well through the dense waxy layer of the cuticle. Yes, and they do not have a cambial layer, the growth of the stem and root in thickness occurs due to an increase in existing cells. Resistance to 2,4D herbicides is explained by their lack of cambium. In the fight against these weeds, herbicides from the simtriazine group, as well as dual, astix, titus, harmoni, are effective.
CLASSIFICATION OF HERBICIDESHERBICIDES
CONTINUOUS ELECTORAL
ACTION ACTION
CONTACT SYSTEM
SOIL BY GETTING
ACTIONS FOR THE BODIES OF THE WEEDS
Herbicides of continuous action destroy all types of weeds and cultivated plants. They are used in the fields during the absence of crops, as well as for the destruction of weeds on roadsides, irrigation canals, parking lots of agricultural. techniques where it is impossible to apply agrotechnical methods to improve them, etc.
Herbicides of selective action destroy some plants in certain dosages, but do not damage others. They are applied to destruction of weeds in crops of page - x. cultures.
According to the nature of the action on the organs and tissues of the plant, herbicides are divided into contact and systemic.
Contact herbicides damage only the aerial parts of plants in places of direct contact. The roots are not damaged. These include: dual, raglan, nitrafen, lasso.
Systemic herbicides penetrate into plant tissues and can move within them. Cause disruption of cell growth and division, tissue proliferation,
deformation of stems and leaves, the formation of aerial roots.
According to the method of application, herbicides are divided into ground and soil. Aboveground herbicides are mainly applied by spraying.
Soil preparations include preparations that are applied by introducing into the soil. Many drugs act both on above-ground organs and through the roots of plants. The introduction of herbicides according to the methods of processing can be continuous, row, tape and focal.
With continuous processing, the drug is evenly sprayed over the surface. Row and band application is used in the fields of tilled crops. Spot application is used to destroy curtains of quarantine and especially malicious weeds.
According to the terms of processing, they distinguish: presowing introduction of a herbicide into the soil with incorporation by cultivators or harrows. This is how eptam, treflan, tri-allat are introduced: post-sowing introduction into the soil without incorporation or with simultaneous incorporation (simazine, prometrin); pre-emergence spraying of the field a few days before the emergence of seedlings of cultivated plants (potatoes, corn, carrots, etc.), but when weeds emerge (2,4-D, 2M-4X), post-emergence spraying of winter and spring cereals, corn as a result, which affects the above-ground organs of weeds; post-harvest processing is necessary to destroy weeds remaining or sprouting after harvesting. For this, soil and leaf herbicides are used, which lose their activity by the time of sowing the next crop.
Herbicides have the following physical forms:
Powders that are soluble in water (dalapon) and form a stable in water
chivy suspensions (simazine);
Aqueous solutions (banvel) and water-soluble concentrates (am. Salt (2,4-D) emulsion concentrates that give stable emulsions of various
Concentrations (carbine, propanide)
Granules containing 10% herbicide, filler and adhesive
patel (triallate)
The main method of applying herbicides is spraying. The dose of a technical preparation per 1 ha, if it is not indicated in the manufacturer's documents, is determined by the formula
Dt \u003d 100 Do / A; where
Dt - dose of technical preparation, kg/ha;
A - the amount of active substance in the preparation,%.
The effectiveness of herbicides application depends on environmental factors.
With an increase in air and soil temperature, the sensitivity of plants to herbicides increases, since at a higher temperature, the absorption and movement of herbicides in plants is much faster. Most herbicides used in the seedling phase are maximally toxic at a temperature of 14-25°C, and at a temperature of 8-10°C they are weak. At low temperatures, mainly when processing winter crops, esters of 2,4-D effectively act on weeds, the effect of which is less dependent on temperature.
On hot days, spraying of crops with herbicides is carried out in the morning and evening hours, and on cold days during the day.
The wind disrupts the uniform distribution of the liquid over the area, increases evaporation and drift. Droplets with a diameter of 100 microns or less are carried away at a wind speed of 3.6 m/s. With an increase in droplets, the drift decreases, and when their diameter reaches 325 μm, it stops. Therefore, optimal working conditions for spraying crops are created in calm weather.
The activity of soil herbicides depends on the moisture and temperature of the topsoil. The introduction of certain herbicides (simazine, pyramine) into dry soil promotes detoxification, as a result of which the risk of damage to crops sown in the next year increases. crops sensitive to this herbicide.
At high humidity soil and heavy rainfall, some herbicides penetrate into the lower layers of the soil, and weeds will germinate in the upper layer, freed from the herbicide.
Rain falling immediately after herbicide treatment washes the preparation from the surface, thereby reducing its effect. In addition, the herbicide washed into the soil can have a toxic effect on the protected plants, penetrating the roots, which are more sensitive to herbicides than the above-ground organs. This must be taken into account when planning the work.
APPLICATION OF HERBICIDES IN CROPS OF BASIC CROPS
On grain crops, herbicides in the form of salts and esters, derivatives of 2,4-D and 2M-4X, are widely used. In crops of winter and spring wheat, winter rye, barley, millet, sorghum, herbicides 2,4-D are used with a consumption rate of 1.2-1.6 kg/ha in the tillering phase of the crop before the start of the tube. These include dezormon (60 g / l), dikamin (600 g / l), luvaram (610 g / l), banvel (480 g / l) - 0.15-0.3 l / ha, astix (600 g /l).
To combat perennial weeds, doses are increased by 15-25%. Against resistant species of weeds to this group of herbicides (medium chickweed, odorless chamomile, tenacious bedstraw, field violet, highlander species), as well as perennial cereal species, preparations of the 2,4-D group are used in a mixture of dicamba, picloram or chlorsulfuron - lontrim (360
g/l), trezor (596 g/l), dialen super (564 g/l), grodil (750 g/kg), lintur (659 + 41 g/kg), granstar (350 g/l), harmoni (750 g/kg), phenphys (310 g/l), octigen (419 + 75 g/l), starane (200 g/l), cowboy (17.5+368 g/l).
Doses of application of these herbicides on grain crops do not exceed 0.2-0.9 kg/ha.
Promising herbicides include lintur (690 g/kg/ha, diphesan (362 g/lml/ha), aurora (500 g/kg/ha, topic (80+20 g/l) - 0.3-0.4 l/ha, grunch (600 g/kg/ha, secateurs (187 g/kg/ha, satis (60+120 g/kg/ha.
These new generation herbicides are highly effective.
In crops of grain legumes, soil-acting herbicides treflan (240 g/ll/ha, gezagard (500 g/kg/ha) are used before sowing or the soil is sprayed before sowing crops with immediate incorporation. For vegetative weeds of soybeans, beans use trophy ( 900 l/ha, 5 l/ha, bazagran (480 g/l) - 1.5-3 l/ha, frontier (900 g/l) - 1.1-1.7 l/ha, triallat (425 g/ha) l) - 1.6-3.2 l / ha.
Fusilad-super (125 g/ll/ha, pivot (100 g/l) - 0.5-0.8 l/ha, nabu (117 g/ll/ha) are used in pea crops.
The cultivation of corn for grain and green fodder without herbicides is almost impossible.
Before sowing, the soil is sprayed with immediate incorporation of trophy soil herbicides (900 g/l.5 l/ha, stomp (330 g/ll/ha, dual (960 g/l)) - 1.6-2 l/ha, (900 g/ll/ha, merlin (750 g/kg) -0.1 0.16 kg/ha.
Against dicotyledons, including those resistant to 2,4-D salt, mixtures of bentazone and atrazine are used - laddock (200 + 200 g / l / ha, cambio (320 + 90 g / l - 2-2.5 g / l, as well as mixtures of esters and 2,4-D - buktril (225 g / l) - 1.25-1.5 l / ha,
pardner (225 g/l,5 l/ha, titus (250 g/kg/ha, harmoni (750 g/kg/ha.
From promising basis (500+250 g/kg/ha/circle (140 g/lml/ha), pressing (36+351 g/lml/ha.
Soil-acting herbicides hexi-Lur (800 g/kg/ha and Eptam (720 g/l) - 2.8-5.6 kg/ha) are used on sugar beet.
Against cereal weeds, crops are sprayed in the phase of 2-3 leaves of the culture and tillering in weeds with the following herbicides: shogun (100 g/l) - 0.6-0.8, furore-super (69 g/l) - 0.8- 1.2, zeleck-super (104 g/l) - 0.5-0.8 l/ha. Against dicotyledonous and some types of monocotyledonous weeds - betanal (160 g / l) - 4-6, burefen (160 g / l) - 4-6 l / ha, caribou (500 g / kg) - 30 g / ha, pyramine ( 430 g/l) - 6-8 l/ha. In the fight against perennial species, Lontrel-g / l) -0.16-0.66 l / ha is used.
Among the promising herbicides in the fight against cereal weeds are panther (40 g/l) - 0.75-1, select (120 g/l) - 0.6-0.7, nabu (117 g/l) - 1- 3 l/ha; with annual dicots - reggio (300 +50 +50 g/l, flirt (418 +42 g/l) - 5 l/ha.
In sunflower crops, the use of herbicides requires care, as crop seedlings can be damaged. Before sowing, soil-acting herbicides treflan (240 g/ll/ha, racer (250 g/ll/ha, dual (960 g/l)) - 1.6-3 l/ha, harnes (900 g/l) - 1 .5 -2 l/ha.
In the phase of 2-4 leaves, they are treated with Zellek-super (104 g/l) - 0.5 l/ha, frontier (900 g/l) - 1.1-1.7 l/ha, fuzilad-super (125 g/l, 5 l/ha.
In crops vegetable crops soil-acting and post-emergence herbicides are used for vegetative plants. When spraying the soil, treflan (240 g/l, 5 l/ha) is used. In the fight against cereal weeds, nabu crops are sprayed in the phase of 2-6 leaves (114 g/ll/ha, panther (40 g/l) - 0.75 -1 l/ha, titus (250 g/kg/ha, against annual dicotyledonous Simeron (250 g/kgkg/ha.
On perennial legumes, soil herbicides zen-cor (700 g/kg) -1.4 kg/ha, gezagard (500 g/kg) - 3 kg/ha, eradican (720 g/ll/ha) are used. In the fight against cereals weeds during the dormant period before the beginning of the regrowth of the crop or in late autumn apply kerb (500 g / kg kg / ha, panther (40 g / l) - 0.8-1.2 l / ha, against annual dicotyledonous agritoxes (500 g / l) - 0.8-1.2 l/ha, bazagran (480 g/l) - 2 l/ha, chwastox (500 g/l) - 0.8-1.2 l/ha, pivot (100 g/l ) - 0.5-0.8 l/ha.
On fallows in orchards, nurseries and berry fields, herbicides of continuous and soil action are used. For these purposes, glysol (360 g/ll/ha), glyphos (360 g/ll/ha, zero (360 g/ll/ha), roundup (360 g/ll/ha.
The basic principle of rational chemical control lies in the full consideration of the ecological situation, accurate knowledge of the ecological thresholds of weed damage. This allows you to reduce the area and frequency of chemical treatments without harming the protected crop. In order to prevent the spread of resistant weeds, it is necessary to use preparations with a broad selective action, as well as their mixtures.
The use of herbicides with optimal standards consumption of preparations and working compositions in the most stable stages of organogenesis in cultivated plants and the most sensitive in weeds, allows to achieve high biological efficiency, reduces the cost of treatment, to obtain high yields in terms of quantity and quality without residual amounts of herbicides, does not cause disturbances in agrobiocenoses s.-x. cultures and in the environment.
It must be emphasized that only with a rational combination of agrotechnical, biological and chemical control measures, taking into account the biological characteristics of weeds and plants, it is possible to clear the fields of weeds in a short time with the lowest labor and cost.
Application of herbicides in crops of major crops
Grain crops - 2,4-D with a consumption rate of 1.2-1.6 kg / ha per phase
tillering of culture before the beginning of an exit in a tube.
Desormon - 0.5-0.8 l/ha, luvaram - 0.15-0.3 l/ha, astix - 0.2-0.3 l/ha.
With perennial weeds - super dialen (564 g/l), lintur (659+41 g/kg),
Cereal legumes - apply herbicides before sowing
soil action.
Treflan - 4-6 l/ha, gezagard - 3-5 l/ha.
For vegetative weeds of soybeans, beans - trophy - 2-2.5 l/ha, bazagran - 1.5-3 l/ha, triallat - 1.6-3.2 l/ha.
Peas - fusilade-super - 1-2 l/ha, pivot - 0.5-0.8 l/ha, nabu - 1-3 l/ha.
Maize for grain - before sowing - soil-acting herbicides -
trophy - 2-2.5 l/ha, harness - 2-3 l/ha.
In crops - titus - 40 g/ha, harmoni - 15 g/ha.
Sugar beet - furore-super - 0.8-1.2 l/ha, zellek-super - 0.5-0.8 l/ha, betanal - 4-6 l/ha.
Sunflower - before sowing the application of soil herbicides
actions - treflan - 4-10 l / ha, harness - 1.5-2 l / ha.
In the phase of 2-4 leaves - frontier - 1.1-1.7 l / ha, fusilad-super - 1-1.5
Perennial legumes - soil herbicides - zenkor - 1.4 kg/ha, eradican - 5-6 l/ha, panther - 0.8-1.2 l/ha, pivot - 0.5-0.8 l/ha .
On fallows in orchards - continuous herbicides - glisol - 26 l / ha, glyphos - 2-8 l / ha, roundup - 2-4 l / ha.