weeds: it’s time to use the alternate term for...

Popular Article

Weeds: It’s Time to Use the Alternate Term for Weed

R. Gowthami 1*, K. V. Raghavendra2, N. M. Lepakshi3 R. Shashank4 and M. Dhananivetha5

1Ph. D. Student, Agricultural College & Research Institute - Madurai, Tamil Nadu Agricultural University, Coimbatore, India 3University of Agricultural Sciences, Bengaluru, India

4Government Science College, Bengaluru, India *Email of corresponding author: [email protected]

Introduction Life on Earth mainly depends on plants and it is very important for survival of human beings. Weeds are the plants, which grow where they are not wanted. Weeds can also be referred to as plants out of place. There are approximately 250,000 species of plants worldwide, of those about 3% or 8000 species behave as weeds. Our human activities create weed problems since no plant is a "weed" and “useless” in nature. Though we may try to manipulate nature for our own good, nature is persistent. Through the manipulation process, certain weeds are controlled, while, other more serious weeds may thrive because favorable growing conditions for them also have been met. Weeds are naturally strong competitors and those weeds that can best compete always tend to dominate. Both humans and nature are involved in plant breeding programs. The main difference between the two programs is that man breeds plants for yield, while nature breeds plants for survival. Weeds, thought found to cause considerable damage in various ways they are not regarded as absolutely useless and many advantage have be attributed to them. Many weed plants have health benefit and have the numerous mechanisms to survive extreme field conditions. It has the ability to grow faster and utilize the resource in effective manner. Therefore we are having the chance to cultivate and convert some weeds species to crop by this we can earn the market in international level.

Popular Kheti Volume -3, Issue-3 (July-September), 2015

Available online at www.popularkheti.info © 2015 popularkheti.info

ISSN: 2321-0001

Weeds, thought found to cause considerable damage in various ways they are not regarded as absolutely useless and many advantage have be attributed to them. Many weed plants have health benefit and have the numerous mechanisms to survive extreme field conditions. It has the ability to grow faster and utilize the resource in effective manner. Therefore we are having the chance to cultivate and convert some weeds species to crop by this we can earn the market in international level. While the term "weed" generally has a negative connotation, many plants known as weeds have millions of beneficial medicinal properties.

Popular Kheti ISSN: 2321-0001 179

Popular Article

While the term "weed" generally has a negative connotation, many plants known as weeds have millions of beneficial medicinal properties. Hence weeds are also called as "Beneficial Plants or Herbs”, “Treasure of Phytochemicals”, “Ethno-botanical Plants”, “Folk Medicine” and “Antioxidant Bowl”, “Mine of Useful chemicals”

Beneficial Properties of Weeds

Weeds as fodder: A large number of weeds are consumed by milch animals as fodder. Most weeds are preferred by cattle and weeds like Rynchosia aurea, R. capitata and Clitoria terneata are very good fodder legumes and also filed bind weed (Convolvulus arvensis). Weeds help the poor landless farmers who do not have enough land to cultivate fodders for their animals and weeds consumed as green vegetables and some weeds have good palatable taste. Many weeds are good quality forage crop as they meet most of the recommended values for cattle maintenance. Less utilized tropical plants represent a potential food source with high protein content and good nutritive value.

Weeds as green and green leaf manure: A large number of weeds have profuse leaf growth and they can be incorporated in the soil as green manure, hence it adds considerable amount of organic matter and plant nutrients. Excellent compost can be made out of many weed plants. Weeds add about 5 to 15 tonnes of green matter per hectare depending upon weed species and their growth. Calotropis gigantea, Tephrosia purpurea and are largely used as green leaf manure for paddy lands. Cassia hirusta and indigenous cassia tora are good leguminous green manure plants. 1. Weeds as fuel: Many weeds have profuse growth and after drying this weeds can be used as fuel. Rural people make benefit by making charcoal out of it and are marketed. All most all broad based leaves can be used as fuel after proper drying. 2. Weeds as soil binders: Many of the broad leafed weeds and grassy weeds acts as soil binders by preventing soil erosion during heavy rainfall. Cynodon dactylon, Agave americana, Panicum repense are an excellent soil binder; keeps bunds in position and prevents soil erosion in high rainfall regions and hilly slopes. The roots of the weeds bind strongly with soil in the root zone and do not allow the soil to erote from one position to another. 3. Weeds check water Erosion: Weeds growing on desert lands, waste lands and sloppy fields lower wind and water erosion and also help for protection of the environment. Cynodon dactylon and Agave americana prevents water erosion and help in maintaining soil fertility. 4. Weeds as leafy vegetables: Many weeds are used as food for human consumption either a part or whole plant. It is used as vegetable by poor people. Weeds are also called as famine foods, poor people food, poor man’s vegetables. These GLV are used since ancient periods as source of food as they contain many nutrients and minerals which are helpful in maintaining human health. Leafy vegetables

Botanical name Family Botanical name Family Achyranthes aspera L. Amaranthaceae Commelina communis L. Commelinaceae Allmania nodiflora (L.) R. Br. Amaranthaceae Digera muricata (L.) Mart. Amaranthaceae Alternanthera sessilis (L.) R. Br. Amaranthaceae Eclipta alba L. Asteraceae Amaranthus blitum L. Amaranthaceae Emilia sonchifolia L. Asteraceae Basella alba L. Basellaceae Oxalis corniculata L. Oxalidaceae Boerhavia diffusa L. Nyctaginaceae Phyllanthus amarus L. Euphorpiaceae Cardiospermum helicacabum L. Sapindaceae Portulaca oleracea L. Portulaceae Cassia fistula Fabaceae Raphanus sativus L. Brassicaceae Celosia argentea L. Portulaceae Sesbania grandiflora (L.) Pers. Fabaceae, Centella asiatica (L.) Urban Apiaceae Solanum nigrum L. Solanaceae Chenopodium album L. Chenopodiaceae Solanum trilobatum L. Solanaceae Cleome gynandra L. Cleomaceae Sauropus andragynus (L.) Merr. Euphorbiaceae Cleome viscosa L. Cleomaceae Trigonella foenum-graecum L. Apaiaceae


Gothami et al., 2015, Pop. Kheti, 3(3): 179-183

Popular Article

are naturally available important constituent of nutraceuticals and are also called as pot herbs, greens, vegetable greens, leafy greens or salad greens. The leafy vegetables are said to tone up the energy and vigour in human being. Many of the weeds are rich in minerals and it acts as dietary component in rural lifestyle. 5. Weeds as medicinal plants: Weeds are highly valued in traditional medicine systems and have been used by rural people to address many of our today’s major health problems. There are about 120 weed species in India used as medicinal purpose. Weeds receive more attention because 80% of the world population continues to rely mainly on traditional medicine systems. Many weeds possess phytochemicals which have been shown as a promising alternative to the synthetic drugs and have been used by rural people to address many of our today’s major health problems. Weeds as medicinal plants

Botanical name Ailments Mode of administration Abutilon indicum Piles Root extract is taken orally twice a day for two weeks Argemone mexicana Blood pressure Root extract is taken orally Cleome gynandra Wounds Leaf paste is applied twice a day for wound until cure. Cleome viscosa Gastric problems Decoction of seeds is taken daily once for 7 days. Crotolaria juncea Blood purification Leaves are used to purify blood Cynodon dactylon Dysentery Extact from the whole plant is taken orally Cyperus rotundus Stomach -ache. Tuber paste is applied twice a day for two days Datura metal Ear ache Seed powder mixed with warm coconut oil and applied to ear Oxalis corniculata - Leaves are consumed as vegetable Phyllanthus niruri Jaundice Root extract is taken in empty stomach for 2 - 3 weeks Tridax procumbens Wounds The leaf paste is applied on wounds and cuts

6. Weeds have economic importance: Weeds also plays a major role in rural development, by using some weeds we are having chance to develop many small scale industries and self help groups to make useful materials and in other hand it gives employment for rural people. The weeds has commercial value are listed below.

Botanical name Economic importance Cypreus pangorei Stalks yield good material for making mats Cyperus corymbosus Stalks yield good material for making mats Cyperus corymbosus For preparation of bouquets Cymbopogon citrates Citronella oil C. Martinii Used for manufacturing aromatic oil. Lantana camera Interior decoration Agave sp. Used for fencing purposes Agave sp. For fibre extraction Cyperus rotundus Useful in manufacturing of agarbattis Calotropis gigantea Silky hairs of seeds are used for stuffing pillows and fibre manufacture Chrozophora rattleri The plant yields a dye. Saccharum squarrosus Used for fencing purposes Argemone mexicana The seed yields a valuable painters oil Abutilon indicum Stems yield fibre which is suitable for preparation of ropes Jathropha gossypifolia Excellent biodiesel crop Typha angustata For making screens Euphorbia hirta Used for latex extraction Lantena camera Flowers are used for local decoration Euphorbia pulcherima Leaves are used for the preparation of flower bouquets Vicoa indica Used for indoor decorations



Popular Article

7. Weeds used for reclamation of problematic soils: Some weedy species are pioneers of degraded landscapes where the soil is worn-out or nearly destroyed. Such weedy species are necessary to the healing process of the landscape, as their decaying organic matter improves the quality of the soil and the sets the stage for the succession of non-weedy plants – alfalfa, red clover. The application of powder of the weed Argemone maxicana @ 2.5 tonnes/ha is useful for reclamation of alkali soils. 8. Weeds have Nematicidal Properties: Several weed species exhibits nematicidal properties for the management of root knot nematode. The reduction of nematode population may be attributed to the production of nematicidal substances like terthienyl, triterpenoid and other alkaloids by weeds. Fresh leaf extracts of Datura stramonium, Calotropis procera, Verbesena enceloides, Parthenium hysterophorus, Morus alba, Phyllanthus amarus, Eichhornea crassipes, Ricinus communis, Jatropha curcas, Azadirachta indica, Tinospora cordifolia, Clerodendron multiflorum, Catharanthus roseus and Adhatoda vesica . 9. Weeds are used for Religious Purpose: Some weed species plays an important role in religious point of view. These weeds were used for worshiping different gods and it was believed as sacred.

Botanical Name Religious purpose Calotropis gigantean flower Ganapaty pooja festival and used as a garland for hanuman Calotropis gigantean leaves During worshiping snakes during maghamasa Cynodon dactylon For worshiping hanuman Cynodon dactylon Ganapaty pooja festival Clitoria ternata Used for worshiping shiva as the flower indicates shanku Ocimum sanctum Garlands for Hanuman Ocimum sanctum Used for Krishna pushpabhishekam Saccharum spontaneum Used in all temples homam Gloriosa superba For worshiping lord Lakshmi Gloriosa superba For worshiping Gowri hence commonly called gowri

pushpa in kannada Calotropis gigantean flower As a garland for Hanuman All leaves including non- weed species For lord Ganesha during ganesha festival Ecbolium viride Used for worshiping Saraswathi Leucas aspera Used for worshiping Lord Shiva Ruellia tuberosa For worshiping gods

10. Weeds as Trap crops: Sometimes the weeds are more attractive to the crop pest than the crop itself. In that case pest population on the host can be decreased due to the dilution effect of the weed and acts as a trap crop. 11. Weeds as a biopesticides: About 2000 plant species are reported to contain compounds with pest control properties. Although the efficacy of extracts from most of these plants is poor compared to commercial synthetic pesticides, they can still contribute substantially to pest control when their use is integrated with other measures and often have the advantage of low human toxicity. 12. Weeds as biofungicides: Some of the weed plant extracts which are active against insect pests are also active against fungal and bacterial pathogens. Datura stramonium has been shown to provide some control of both Alternaria leaf spot (Alternaria macrospora) and bacterial blight (Xanthomonas campestris pv. malvacearum) on cotton. Hence weeds can be used as biofungicides. 13. Weeds as source of genes: Some of the weeds have been cultivated in the past as crops and others are progenitors of, or closely related to, wild progenitors of crop plants. Some are sufficiently close genetically to their crop relatives that introgression is common and contributes to the diversity of the crop species population, while selection for uniformity in crop species results in a loss of genes, and the consequent increasing instability of agroecosystems. Weed relatives of crop species may remain as a



Popular Article

reservoir of genes and should be conserved as they may be needed in the future and can be used in breeding programme to transfer desirable genes from weed species to cultivated species. Saccharum spontaneum Used for thatching purpose and breeding sugarcane varieties for

including hardiness. 14. Weeds as hosts for beneficial insects: Weeds provide a habitat for beneficial arthropods where they can and physical shelter, the polyphagous species can and alternative hosts, a diverse flora may provide pollen, nectar or water and perhaps a more favourable microclimate than is available within the cropped area, especially if it is a monocrop. Some predators and parasites are particularly dependent on certain weed species to maintain their populations. 15. Weeds for beautification of landscape: At present landscape beautification attaining a important position in the places lie hotels, restaurants, offices, companies etc. Most of the weeds are good ornamentals. For example Lantana camera is introduced as an ornamental crop. Stems of Cyperus rotundus and Cynodon dactylon are extensively used in preparation of lawns. 16. Weed as indicators for problematic soils - Weeds are useful as indicators of good and bad soils. The presence of these weeds indicates the condition of the soil, so that reclamation measures can be taken out before growing the crop.

E. Colonum Occurs in rich soils Cymbopogon Poor light soil Sedges Found in ill-drained soils.

17. Weeds for carbon recycling through carbon sequestration: Field of exposed soil always suffers a net loss in organic matter and releases carbon dioxide, while a field covered with crops and/or weeds takes up carbon dioxide. This concept of carbon sequestration is an added advantage of sustainable and organic farming.

18. Weeds as grain protectants: Grain storage plays an important role in preventing losses which are caused mainly due to insect pests, pathogens and rodents. Several weed plants can be used as grain protectants during storage like Lantana camera, Calotropis gigantean.

Conclusion Apart from the competitive nature of weeds with crops for soil, water and nutrients, they also possess several beneficial properties which help in reducing cost of cultivation, increases additional income to the farmers etc. But unfortunately these weeds are being destroyed during cultural operations in different crop fields and this may lead to the possibilities of losing the weed species. Even though these weeds affect the main crop in several ways, the rural folk can protect these weeds for future generation by collecting and preserving by following different preservation methods and also they can maintain in uncultivated and agriculturally not suitable fields. Conservation of weeds also helps in phytoremediation, reduced erosion, increased infiltration of rain water which recharges ground water table, enhance carbon sequestration. Hence these weeds can become an additional source of income for the farmers and at present the term weed should be changed to Beneficial Plants.



weeds: it’s time to use the alternate term for...

Documents