I. Occurrence of weeds
1, fast growth: the use of light, water and fertilizer than crops, the ability of strong growth of the asexual reproduction of the weeds very fast, compared with earlier partial mature crops.
2, more solid, continuous strong resistance, floor: It can produce 1-3 generations, tens of thousands - hundreds of thousands of seeds, ripe seeds fall off the general is likely to result, causing soil infection. Weeds take up space in the short term, covering the ground, because a greater amount of seed per plant. As thousands of times to generate weed seeds, weed control measures are effective even if a few thousand plants per acre of farmland weeds in the year left, can produce tens of millions or even hundreds of millions of seeds, next year's still a serious place.
3, seedlings mature mixed: weed seeds, crops mature earlier than the maturity stage is also inconsistent, usually flowering side, while strong, mature side, with the maturity of the field scattered with the loss, breeding several generations a year. For example, small pigweed in the Huang-Huai River Basin in late April each year to early May flowering, fruit ripening in late May until October still flowering and fruiting. Therefore, these weeds in the wheat field, Akita, vegetable fields and orchards, such as different field or have occurred in different seasons.
4, the weed seeds are ripening more features, some are flowering weeds are removed, the fertilized ovules can develop into seeds. Some post-weed, barnyard grass, such as rice paddies, fruit ripening rice generally higher than 10 to 20 days in advance. Wild oats in wheat, Alopecurus, sophia mature wheat and other weeds usually fall off before the fruit has matured. Most of the seedling weeds is not neat, such as shepherd's purse, pigweed, chickweed and other weeds in addition to January the coldest and the hottest August 7 does not occur, the emergence of flowering all the year round. Digitaria sanguinalis, Setaria viridis, Eleusine indica, Eragrostis, iron, amaranth, and black nightshade, etc. 4 August emergence could grow corn, cotton, soybean, peanut and other autumn crops and vegetable fields and orchards of the main weeds. Each field in a pouring rain one drop of water or weed emergence will have a peak, it is easy to form grass weed shortage of farmland and difficult to remove the main reason, but also to Control in inconvenience.
5, long life (sleep): cress seeds life of 40 years, field bindweed can survive for 50 years.
6, plasticity, and stress resistance: the ability to survive under adverse environmental conditions and adaptation is more prominent, have a greater priority than the crop type.
7, a variety of reproduction and pollination ways: asexual reproduction by seed or root, stem, bud propagation, different flowers can be both self-pollination, by wind, insects, animals, people can be pollinated.
8, a variety of modes of transmission: the seed by wind, insects, animals, livestock, water, agricultural machinery, irrigation, farmyard manure mixed with crop seeds, grain.
Mimicry of: such as millet and rice, and millet Setaria similar morphological and physiological behavior, labor and machinery than grass is very difficult.
Second, the harm of weeds
1, and crop competition for fertilizer, light, water, space: weeds have developed root system, stem node prostrate on the ground can take root, strong absorptive capacity, seedling stage of fast growth, photosynthetic efficiency, the product quickly to the new leaf photosynthesis conductivity distribution, and rapid vegetative growth to reproductive growth transition, with a special performance of the crop interference, capture water, nutrients and sunlight is much greater capacity than the crop. Has superior growth characteristics and prominent environmental adaptability.
2, lower crop yield and quality: poison mixed with wheat after wheat, ground into flour poisoning effect on people, people if eaten can cause dizziness, coma, nausea, vomiting, diarrhea, cramps, severe cases can cause death. Livestock poisoning from eating a certain amount of feed wheat, the same can cause poisoning or death. With barnyard grass in rice will reduce the grain quality, the meter rate. Overgrown orchard fruit color and quality is also affected.
3, impeding agricultural operations: if the wheat in Galium aparine, sophia, Cephalanoplos profusion of barnyard grass in rice, amaranth Monochoria more grass and water, the crop is easy lodging of grain weight, reduce the yield. Rice lodging, the harvester can harvest. Soybeans, corn in large velvetleaf, serious weeds, harvesting grass easily blocked failure. In addition, if the harvest is mixed with more difficult to dry grass, prone to mildew, resulting in losses.
4, the breeding of pests and diseases (intermediate host): If the mass poisoning of plants, some weeds virus transmission by insects infected with the virus, then the insects spread the virus on to weed crops, and thus become pathogenic virus disease occurred in one of the important ; aphids in the thorn vegetables, shepherd's purse and other winter weeds; barnyard grass is planthoppers and leafhoppers in the middle of the host.
5, the impact of human and livestock health: Toxic wheat flour led to more than 4% of people were poisoned or even death; livestock poisoning from eating a certain amount of feed wheat, the same can cause poisoning or death. Therefore, the drug was listed as the national wheat quarantine. Cattle eat feed with wild oat seeds, often caused by the mouth, esophagus and gastric mucosal inflammation; ragweed pollen can cause allergic symptoms were sensitive.
6 of water conservancy facilities and river navigation: the canals, slowing water flow, sedimentation, and provide habitat for the rodent nesting conditions for the dam damaged.
Third, the classification of weeds
Weeds: Africa is the cultivation of agricultural plants, agricultural plants more harm than benefit. There are 50,000 kinds of weeds in the world, of which there are 5,000 agricultural weed, China has 580 kinds of agricultural weeds.
According to characteristics of breeding and occurrence of
Annual weeds (278 species): seed germination, vegetative growth, flowering, death within a year, propagated by seed, such as wild oats and Amaranthus retroflexus.
Students can be said for two years more years old (59 species) weeds: the first winter in the vegetative growth to seed the second year of flowering and seed breeding. Such as shepherd's purse, cress.
Perennial weeds (243 species): flowering and fruiting times, such as taxi, Equisetum, alligator grass.
Vegetative organs: seeds, taproot, rhizome, tubers, rhizomes, corms, bulbs, stems and leaves section block.
According to morphological features:
Broadleaf weeds (77 subjects): generally refers to dicotyledonous weeds, there are some monocotyledonous weeds, two leaves, large leaves, leaves with raw angle, flat leaves, vein network, a few have petioles parallel leaf veins; Stem round or four-prism, as a circular arrangement of vascular bundles within the stem, with the formation of layers, secondary tissue was well developed; root for the taproot.
1) Compositae (77 species): capitulum, spent two types, internal to tubular flowers, outside the ray florets.
2) Cruciferae (25 species): often the root leaves, flowers bisexual, racemose, 4 sepals, 6 stamens
Piece, symmetrical students. 3) Chenopodiaceae: leaves alternate, without stipules, flowers are not significant, intensive, small nuts.
4) Polygonaceae (27 species): internode expansion, alternate, simple leaves, petiole often extended into the base of the stipules membranous sheath care, small flowers, flower clusters issued from the sheath, achene.
5) Amaranthaceae: nutrition body with red pigment, Leaves opposite or alternate, without stipules, small flowers, not significant, group health, or spikes, small nuts.
6) Lamiaceae (28 species): a rectangular stem, leaves simple, opposite, whorled cymes, irregular gender flowers, small nuts.
7) Convolvulaceae: wound herb, and some are latex, axillary cyme, spends a great shape, funnel-shaped corolla, ovary superior, capsule.
Weeds (66 species): monocotyledonous weeds, a cotyledon, leaf narrow, veins parallel, erect leaves, no petiole, leaf sheath at the side of the longitudinal split; Stem round or flat, stem vascular bundles within the overall spread no cambium, fibrous root system is.
Sedge weeds (35 species): a single cotyledon, leaves narrow and large veins parallel to the growth of leaves erect, without petiole, leaf sheath closed into a tube; stem flat triangular or triangular, each a cylindrical, non-section, stem Solid, not a hollow section, the root system is fibrous.
According Habits:
A, land of weeds: (abbreviated)
B, forest weeds: (abbreviated)
C, grass weeds: (abbreviated)
D, aquatic weeds:
Submerged weeds: If Sagittaria pygmaea;
Floating weed: as Potamogeton, Qingping; algae: water sponge;
Emergent weeds: water sedges, reeds and so on.
E, environmental weeds:
F, parasitic weeds (weeds heterotrophic): If the dodder, some or all of these weeds have been lost in photosynthetic capacity of self-synthesis of organic nutrients, and parasitic or semi-parasitic lives.
Fourth, the major grass weeds (66 species):
Alopecurus (wooden club grass):
Identification points: height 15-40CM. Clustered bar, base geniculate, sheath shorter than, the film quality of seed, panicle, lime green, orange and yellow flowers.
Features: seed propagation, the more annual or annual herbs. November -2 ,4-6 months for the seedling fruit month period.
Distribution and Damage: Fit was born in moist soil, mainly in the South provinces.The main rice crop damage of wheat, canola and other crops.
Wild Oats (oat grass):
Identification points: height 30-120CM, solitary or clustered, sheath longer than the internode, leaf sheath relaxation, ligule membranous transparent. Panicles, long 25MM, Health 2-3 flowers.
Features: seed propagation, the more annual or annual herbs. Autumn, spring emergence, April heading, May maturity, fast growth.
Distribution and Damage: distribution of the country, the most serious hazards in Northwest China, was born in appropriate fields of dry crops, the most serious crop damage.
Hard grass:
Identify key points: the base of stalk upright or lying, the high 15-40CM, section more swelling. Sheaths smooth, ridges, closed lower, longer than the internodes; leaf tongue dry membranous. More intensive and tight panicle, spikelets stout, upright or flat.
Features: seed propagation, a year or biennial herb. Seedling emergence in autumn and winter or spring, flowers and fruits of the 4-5 month.
Distribution and Damage: distributed in Anhui, Jiangsu, Henan and other provinces.Salinization of the land is in large quantities.
Crabgrass (Sicko grass):
Identification points: stem bunch, expand or tilt base, racemes 3-10, length 5-8CM, the upper alternate, near the lower whorls.
Features: seed propagation, annual herb, 4-6 months seedlings, flowers and fruits from June to November period, seeds mature edge off edge, strong reproductive ability.
Distribution and Damage: The Qinling Mountains, the Huaihe River line north of the region's largest and autumn crops to weed fields. Quantity and distribution occurs in the dry weeds are a first.
Setaria;
Identify key points: the high 20-60CM, clustered, erect or inclined, base occasionally branches, panicle compact cylindrical.
Features: seed propagation, annual herb, more cold-resistant infertile. April-May emergence, 5, 7-mid to late September the formation of the peak gradually matured, after the germination of dormant seeds.
Distribution and Damage: autumn mature fields of dry crops important weeds.
Eleusine indica;
Identification points: crickets, also known as grass, dense and deep roots, hard pull.Stalk arisen.
Features: seed propagation, annual herb. Early May peak of emergence appear for the first time, and then a second time September 7-October peak of maturity.
Distribution and risk: the Yellow River and Yangtze River south of the region for many machines, dry crop fields ripe for the fall against heavy weed.
Leptochloa chinensis;
Identify key points: the high 30-90CM, stalks clustered, erect, or geniculate base tilt.Leaf sheaths glabrous, shorter than the leaves of the more; leaves flat, apex acute, panicles, spindle and branches rough; more purplish spikelets.
Features: seed propagation, annual herb. May-June emergence after another 8-November flowering, mature, results.
Distribution and Damage: distribution throughout South Africa. Cooked dry for the wet autumn crop fields and paddy field weed.
Barnyard grass:
Identify key points: the high 50-130CM, leaf stripe, stem erect, leafless tongue.Panicle, branches of ear-shaped racemes, and students or students with the spindle.
Features: seed propagation, annual herb. Type of weed is a late spring, the normal rate of emergence of weeds generally heading in early July, flowering, mature fruit in August.
Distribution and Damage: Born in paddy fields, dry place in good conditions, more adaptable, the most serious hazard for the agricultural weed.
Bermudagrass:
Identification points: underground rhizomes. Ground creeping stems, leaf sheaths with ridges, the sheath mouth with soft hair, Ligule short, fibrous hair. Linear alternate leaves, spikes.
Characteristics: Perennial herbs, seeds less, small low germination rate, mainly by stolons. Hi light shade intolerant, hi wet than drought, the roots grow new shoots from April 4-May spread rapidly expanding, interwoven into a network which covers the ground; June began to heading, flowering, fruiting, mature and fall off in October.
Distribution and Damage: distributed in the provinces south of the Yellow River Basin and area. Orchard, farmland major weeds. Stem with soil or plant roots revival, it is difficult Control in.
Indiscriminately grass:
Identification points: stem bunch, not branched, high 15-90CM, sheaths glabrous, much longer than the internode, leaf width strip. Panicle, narrow, sparsely branched, erect or inclined students.
Features: seed propagation, a year or biennial herb. Emergence before winter, 4-May 5-June flowering maturity.
Distribution and risk: mainly in the Yangtze River basin. Is an important rice weeds in wheat fields. Has become a weed in some areas.
Fifth, the main broad-leaved weeds
Commelina communis: common name orchid food, late spring annual weeds, herbs, adaptable, both wet and drought-tolerant hi. Seed longevity of 5 years, distribution of the country, in the Northeast in May, the mid-germination seedling emergence, weed in soybean fields, because nine years of drought, it is difficult to ensure the control effect of soil treatment, resistance to strong effects in soybean fields in NortheastPharmacy: Clomazone (Clomazone), Lysimachia Dan (Bentazon), Tiger (fomesafen), Po income (broad-leaved bulk soil treatment), Flumetsulam and so on.
Sonchus: perennial weed roots, roots developed in early May in the Northeast seedling germination, weed in soybean fields, July 8-September flowering in late seed maturation, rhizome propagation based. Against soybean, corn, wheat and other upland crops distributed throughout the country.
Thorn thistle: commonly known as Cephalanoplos, perennial weed roots, with slender rhizomes. Emergence in the northeast early in May, is the weed in soybean fields, 7 months, 8-September flowering in late seed maturity, root development, soil depth 2-3 m, and grow at different depths away a number of horizontal roots, the studentsMost root to shoot, root to shoot propagation. Distributed in the country, against soybean, wheat and cotton.
Equisetum: commonly known as the phalanx grass, Equisetaceae, herbaceous perennial. Propagation-based roots, spores can reproduce, 4 to 5 month old spores stem, soon shed spores mature, dead spores, Health and Nutrition 5 stems in mid to late September, nutrition stem death; fern weeds, place emphasis on acid soil , leaf degradation, the lower part of the joint into the sheath, mainly in the Yangtze River, north of harm wheat, soybeans, corn, fruit orchards and so on.
Elsholtzia: commonly known as wild perilla, Labiatae, annual seed multiplication, the Northeast May 7-August for the emergence of the fruit. Are distributed throughout the country to the northeast, Qinghai, Inner Mongolia and other places as much damage soybeans, wheat, orchards.
Small quinoa: known as gray vegetables, seed breeding, early spring annual weeds germinate in the Northeast in mid -5 of mid-April; two generations a year in Henan, the first generation of March the blade, May blossom, the end of May to early Junegradually mature fruit, the second generation with different phenological autumn crops of different, usually 7 to August germination, flowering in September, October ripening; fertility is strong.
Buddha Block: commonly known as the canopy grass, annual or biennial herb, seed multiplication, October emergence, for the summer crops field weeds on wheat, rape and other hazards heavier.
Shepherd's Purse: Cruciferae, annual or more annual herbs, seed propagation, most of the autumn emergence, seedling winter, early summer, mature shattering, mainly living in moist fertile land, intolerant of drought. Located in the Yellow River, Yangtze River, endangering wheat, vegetable, orchard. Effects Pharmacy: Starane (20% fluroxypyr EC), fast off spirit.
Galium aparine: also known as Lala vine, salad calamity, Solanaceae, annual or more years old, seed propagation, germination fall more, a small amount occurs in early spring.
Alternanthera: also known as water, peanuts, Amaranthaceae Alternanthera, perennial or annual herbs, mainly in winter stems and leaves, shoots mainly asexual reproduction, distribution, the southern provinces of China; infestation of rice, vegetables, cotton, orchards and lakes, a moist The main regional crops refractory weeds.
Six main Cyperaceae weeds:
Cyperus rotundus: also known as sedges, perennial herb, underground tubers, or nuts breeding, to grow a few roots, extend and grow tubers, the roots and tubers, breeding fast. June-July 8-October flowering seed. Located in the South, East, Southwest and other places, against peanuts, cotton, soybeans, vegetables, orchards, and other pests, or planthopper host. Shaped sedge: Cyperus spike the ball, also known as, seed breeding, annual herbs, seeds, small and light, can be scattered with the wind, with water rafting, or with the seeds, spread of animal activities; occur commonly, especially in low-lying paddy fields serious harm.
Cattle blankets: also known as ox hair grass, creeping underground rhizomes with a very thin, rhizomes and seed propagation, burning the body, although small, highly reproductive, spreading rapidly; distribution of the country, seriously affecting the growth of rice for weed.
Ying Lin: also known as small water onion, seeds and roots fan plants, perennial herbs, seeds spread by water; distribution of the country, against heavy weeds in paddy fields.
Flat bar standard grass: also known as Tri-grass, perennial paddy weeds, roots and seeds to reproduce, life 5 - 6 years, almost all over the country, is a rice field weed.
VII Weeds measures:
1, agricultural measures
A crop rotation: cropping system, crop rotation; rotations, crop rotation and the rotation period of different combinations on weed communities in different degrees; human impact of the succession of weed communities.
B deep plowing farming: plowing (turning ridge, flat turn with; deep plowing, shallow plowing alternate), V turn, turn autumn, autumn plowing.
C Selected varieties: a variety of weed seeds vary widely, that is the same weeds in different ecological conditions, seed size is also inconsistent. People mainly use the weed seed size, weight, there is no Mount Mount, smoothness, different floating ability, mechanical, wind, sieve, water and workers in the seizure, removal of the weed seeds, leaving no seeds, no The full robust grain pest species, as used to reduce the spread of harmful weeds, reduce pests and diseases, increase crop yield.Others in the field for chip select, plant ear election or elections, specifically the selection criteria for disease-free ear of robust, without any weed seeds, after singles by species as a seed to give full play to the advantage of two to reduce the complexspread and damage the grass. For example, to prevent the spread of the spread of wild oat, wheat and wild oat take full advantage of different seeds, and wind sifting election, removing a large number of wild oat seeds and other seeds, to prevent the spread of the spread of weeds. In the post-harvest seed for soybeans, soybean dodder seeds are often mixed in the seed, the use of dodder seeds of soybean and soybean of different sizes, with the screening method can clear out the soybean seed Dodder, Cuscuta reduce the spread of soybean spread strains up to 80-90% control efficiency. Soybean Seed plots, a long weed velvetleaf, you can unplug the velvetleaf (immature seeds), and finally closed breeding fighting reserved. Featured weed plant and seed varieties, is an important method to reduce weed infestation.
D Composting: the eradication of organic fertilizers important means of seeds.Organic fertilizer is the main fertilizer sources in rural areas as farmland, but also the root causes of the spread of weed spread. Complex when the sources of raw materials as manure, not only straw, leaves, green manure, garbage, etc., but also with weeds manure, contains a lot of weed seeds inside, without a lot of seeds in high-temperature composting again into the field, to complement and increased the number of weeds, not composting and fertilizer containing weed seeds occur leading to serious Weeds One of the reasons, in the production of this issue should be high priority, high-temperature composting to kill weeds is to prevent the weed seeds an important part of hazard.
E high-density planting: In the Weeds Control in the measures, often using plant height and density of shading effects to control and eradicate weeds, namely, "the grass seedlings bully" and "high-control grass", "to close off grass. "
Stalk crops such as corn, sorghum, sugar cane, most of the height of weeds in these crops lower than 80% to 90% of the weeds growing in the lower part of these crops.Stalk crops compete with weeds in the process, the occupied space, is the absolute advantage in crop photosynthesis, growth flourish. The weed grows in the lower part of stalk crops, occupying less space, light is poor, few see the light, photosynthesis was inhibited, so that weeds are very little nutrients, resulting in weak growth or death of hunger.
Induced by late sowing F: is the use of the biological characteristics of crops and weeds growth characteristics, organized and planned delayed crop planting, so that early weed unearthed, Control weeds before sowing method. Using this method can be directly targeted prevention and elimination of weeds, weeding received good results.
G management of water:
2, Plant Quarantine:
Quarantine regulations is to prevent the spread of weeds and effective communication methods. Quarantine objects such as ragweed, poison wheat, wild oats, dodder seed, sorghum and other highly hazardous to human, livestock, crops, weeds, and more frequently transferred from the kind of process, should be prepared in all aspects of quarantine and the quarantine, so that specialized seed production, processing, mechanization, quality standardization, qualification of varieties and management professional.
3, cultivation, weed: targeted, clean and thorough, simple technology, not only Control in weeds and crops but also to provide good conditions for growth. In the crop growth throughout the process can be repeated as necessary cultivation, weed,
Including: manual eradication, mechanical cultivation, weed and can promote plant growth while herbicides.
4, biological weed control: the use of biotechnology, including fungi, bacteria, viruses, insects, animals, nematodes, weeds and grass grams of grass and weeds using different strains of the role of such content.
Microbial Control in: One control soybean Paul Lu Dodder, F793 bacteria (a Fusarium) Control in melons Orobanche weed Control in such a way fungi;
Insects, animals Control in: ducks, such as rice, can eat some grass weeds in bud; use of geese in the sunflower fields, tobacco feeding parasitic weed Orobanche Tanaka; the western United States to introduce a beetle eradication of Hamas pasture grass, wing tip of a small internal volume has been found that Cyperus rotundus moth's natural enemies, can be spotted feeding on the water Potamogeton borer, living insect eats the negative mud Commelina Weed Control in insects are all methods used.
5, chemical weed control: Weed Control in short chemical herbicide. That the growth of crop and weed characteristics and laws of the type of chemical herbicides and the role of the principle of plants, the impact of various factors on herbicide and the technical requirements in the use of weed Control in the method proved herbicideweed control method is a modern method, which is to eliminate agricultural weed, crop production to ensure that important scientific instruments, has achieved remarkable economic and social benefits. Its characteristics are:
(A) weeding fast and efficient. V-type or motor with a back sprayer manual weeding weeding several times faster, respectively, compared to several hundred times a day aerial spraying herbicide spraying area of several hundred hectares.
(B) effective weed control, pesticide application in due course, one can solve weed spraying, and then people do not need to unplug. With 12.5% of Gallant Control in peanut, soybean, onion Tiandan cotyledons weeds, the control efficiency of 95% to 100%; with 45% of the fear of Control in soy beans, grass weeds up to 95% to 100% of malignant mixed Grass velvetleaf, morning glory, sedges and other effects of 90% to 95%. After application to weeds or the newborn period nipped in the bud, but also between strains of weed control is also relatively clean.
(C) yield significant results. Chemical weed control than manual weeding generally yield about 10%.
(D) of rainfall can not be overcome by manual weeding and mechanical weeding of shortcomings. Manual weeding and mechanical weeding is not carried out in the rain, rainfall after herbicide herbicides on soil moisture content just to meet water requirements, weed herbicides full effect.
(E) Chemical weed control is conducive to integrated control of pests and diseases.Timely elimination of chemical weed control weed, pest removal and cut off some of the intermediate host, wintering sites, as virus hosts, hobbies host, thereby reducing pest damage. Such as the elimination of Alopecurus, wild oats, crabgrass, chickweed, etc. to remove or cut the wheat aphid, Aphis binary intermediate hosts and yellow dwarf disease, scab virus transmission medium.
(F) is conducive to the reform of farming systems. Such as zero tillage, minimum tillage method, planting and reduce the spacing to improve air density, chemical weed control can only solve the shortage of grass, the crop from damage, this alone is difficult to implement manually removed.
(G) in favor of mechanization. Weed Control in a large area, such as when the mechanized spraying, weeding effect, fewer weeds, more conducive to mechanized harvest.
用
菊子曰写博客，就是爽！
用菊子曰写博客，就是爽！
