Many so called 'weed plants' are having medicinal value!

Many natural plants are now rarely found due to their elimination considering them as weeds.

If they become extinct, environmental balance will be disturbed and scope for future research and use of them as medicine will be lost forever.

Weed flowers also add colour to otherwise colourless landscapes and hopefully they don't inhibit native plants :)

Agree with the observations and concerns. The approach to address the problem had accordingly changed from weed eradication to system-based weed management.

Weeds represent the major problem among all pests for it,s effects on agricultural production .Weeds control was too difficult due to it,s growth habits and numerous methods of propagation and survival under different environmental conditions .It,s caused a large losses in agricultural products through reducing quantitative and qualitative characteristics of the yield,besides its competition with main crops for growth elements(Nutrients,Light

I think weeds are menace to crop field so need not necessarily to have removed from other wastelands as all weeds are not harmful to us

Hi

I think these plants play important role by adding oxygen for human beings besides adding biological enrichment to the soil.

regards

I agree with Nilay Norah but his answer still lacks the clarity on the query.

No doubt from field having crops it is a necessity to get rid off them but do other places need chemical application having long term persistent effect.

Similarly one thing is clear if we eliminate any species completely,any new invasive sps may come to occupy the place as per law of ecology.

Dear Ali

We are basically deciding whether to go or not to go.

You have given your views on both the aspects i.e losses or benefits but still the question remains for you to be answered in a clearly.

Thanks Kulvir Singh for your response. As has been discussed, the concept or approach to eradicate has changed to managing the population below threshold level.

some weeds we can use him in medical tretment and eals we can use him as acver for soil to save him from wends and rain but mostly the weeds make losing in the crop by competition on source of life like water and o2 and feeding like macroelemtes

Dear Nilay

I know that elimination is not the way but eradication is.

However my question is altogether different in asking if it is necessary to eliminate them even on from waste lands or roadside.

Ali also is responding wrt field conditions only to which I don't have any objections.

I again repeated the question in this response on which your specific comments are requested.

Sometimes the presence of weeds been necessary especially on arid areas where no cropping presence and in semi desert regions .On the other hand eradication of weeds represent an impossible work because weeds resistance most eradication methods .

In wasteland, the management of weeds may be required if they pose threat to human and animal health. Otherwise, the abundance and diversity may be beneficial.

I think the answer is one of what scale you are considering and what assets you are trying to protect (as well as ones perceptions).

In crop management, aiming for eradication, will help prevent yield losses, and any other impacts (incl. harvest difficulties, weeds being hosts to insect or pathogen pests,....).

We should try and prevent these same weeds spreading back into our crops otherwise our previous efforts may be partly in vain. How far away, on roadsides and in non-crop areas, we should try and eradicate these weeds will be influenced by how far they can spread.

Ecologically, weeds are just a category of plants that 'we' perceive to have more negative than positive impacts. Having said this some very useful plants can be weedy, and some very weedy plants can be useful, hence we have conflict.

Please do see

http://caws.org.au/awc/2012/awc201211951.pdf

for some more of my thoughts about conflict species.

dear Stephen Johnson

i appreciate your feedback.

Initially, two important points should be emphasized.

1. Yes they are plant, and for sure they have positive contributions as mentioned! But the question related to the weeds (the plant that is objectionable or interferes with the activities or welfare of man), not any plant.

So, for being a weed; its harmful (negative) effects must be more than its benefits (positive effects) in a specific area (as mentioned by Stephen)... If not, then we can't accept the plant (weed) in that area as weed which have to be control and/or eliminate/eradicate... So I think there is no conflict, but definition have a vital importance.

2. We need information related to the weed/weeds mentioned in the question for a proper answer!

----

Now;

In general, no need to eradicate or eliminate common weeds, especially in waste lands. But if they have potential to invade new areas (agro-ecosystem, natural ecosystem, bare lands, wastelands etc…) and/or cause any potential economic, ecologic and health problem (based on risk analyses), it is needed to control/manage the weeds even in the wastelands. But still eradication may not be the option.

However, if the weed/plant is a new noxious species, an invasive plant, a parasitic plant etc for the ecosystem/area/region/country etc, eradication programs may be needed to apply even in the wastelands.

Best

Huseyin

Agreed

Hi Kulvir,

I appreciate all the answers above but i think your question is not really based on agronomy/weed science but on ecology.

In that perspective, the interpretation would be little different.

First of all we must consider what is weed? It is a plant in the wrong place. Thus even a highly valued plant can be considered a weed if growing in a field of another plant type. Principally, one wheat variety growing in field on another wheat variety is also a weed. So the perspective of question is very important.

Therefore, if such plants are growing on waste land, ecologically they must not considered as weed. In a wasteland, it serves as a purpose of holding the soil and supporting the microflora. It helps in preventing soil erosion. Could provide food for animals.

Again one must consider that it should not be a plant like congress grass, which in most of the cases is harmful.

Another important thing, most of the oxygen is produced by the sea weeds and algae, thus contribution of the weed plant fraction in the oxygen generation would be less if not negligible. Because, plant type should also be concidered to decide the net gain in carbon dioxide conversion to oxygen. (plant do not photosynthesize for 24 hours).

It would have been better to describe about which plant types you are talking about, the varieties or species.

I hope it would help.

Well Abhijeet

I am talking about only weed plants growing on waate.Nothing about a weed in crop land.Thanks

it will not always be necessary to eliminate them, research could be carried out

about taking advantage of them, that is to say using the old refrain if you can not with the enemy join

A weed in non-agricultural land is not a weed. Weed is a human construct. There are species of plant that grow in agricultural lands that we do not want there and we call such plants weeds. The same species also grow in other places. Such species growing in non-agricultural areas may contribute seeds that then land in agricultural areas. They may also harbor pests (insects or diseases) of agricultural crops. Yet they can also harbor natural enemies of all sorts and they provide nutrition to pollinators that may be useful to the agricultural crop during times when the agricultural crop is not useful to the pollinator.

Thanks for the update Timothy.

I agree with you, however what is your opinion wrt Parthenium hysterophorus in context of my question.

There may be certain more weeds like that which donot have any use at all.

Please share your feedback.best regards

That is a case where the question depends on the weed being a non-native. They may still provide pollen and nectar to pollinators, and might provide some benefits in terms of holding soil. However, they are doing so by displacing more useful species. It is highly recommended not to import invasive species into places where they are not native. The only benefit such weeds have is to give employment opportunities to academic and industry workers who may devote substantial portions of their career attempting to solve/manage the problem.

I agree with Timothy A Ebert. The term "weed" is a human concept indeed! Avery interesting book chapter titled: Weeds guardians of the soil, the authors (Peter Tompkins and Christopher Bird) wrote that despite the bad connotation given to plants that overgrow and choke out more desirable plants: "Weed could also mean herb-derived from the Latin 'herba'-a class of plants having savory, aromatic, or medicinal value. This dichotomy suggests that weeds, like people, can be foes or friends, depending on how or in what circumstances they are viewed (pg. 163). The book reference is:

Tompkins, P. and Bird C. 1989. Secrets of the Soil. New Age Solutions for Restoring our Planet. Harper & Row Publishers.

Abhijeet Singh makes a very good point with the weed concept distinction between agronomy and ecology. Agronomically weeds are controlled to avoid yields losses however an eradication of these is difficult to achieve because weeds are opportunistic, r-strategist, often perennial plants. Thus, their control as predicated by IPM approaches aims at controlling their population sizes so that they may not compromise the economics of the cultivated crop. Weeds (in my opinion) provide valuable ecological services to agriculture like for example pollination as they offer diverse nectar sources to insect species that pollinate also cultivated crops. In addition to this "weeds" patches become refugia for beneficial insect species like parasite and/or parasitoid species that control populations of insects that damage cultivated crops.

Weeds must be eradicated wherever they are. If they are not destroyed on wastelands they will generate seeds that can easily repopulated our fields

To best of my knowledge,pollen of parthenium is causing respiration issues to even non asthmatic people.

I have never seen any kind of honey or nectar collecting insects on flowers of this nuisance weed.

Hence I have confliction for this particular weed wrt second statement of Timothy.

Let us invite opinions.

Thanks to all respondents.

I think no unless they are extremely harmful, because weeds provide several beneficial services.They contribute to soil fertility by adding organic matter and nutrients to it. Weeds protect the soil against erosive forces like wind and water. Moreover, they bring deep seated nutrients on the soil surface. Several of the weeds have medicinal value. They are also helpful in management of pests. Some weeds are wild relatives of crop plants which can be used in the further improvement of the crop plants.

http://www2.hawaii.edu/~theodore/Images/weeds_as_resources_africa.pdf

Article Weeds of major economic importance in rice and yield losses ...

Article Weeds of the major cereal crops and their economic Gujarat, India

Most weeds are annuals, and r-strategists are mostly annuals. K-strategists would be perennial.

In entomology there is a concept of an economic injury level. This is a level of pest where the cost of treatment exceeds the damage the pest will cause. Fields are scouted to monitor pest abundance and a treatment is applied only if the pest abundance exceeds the injury level. I would suspect there is a similar concept for weeds. In rare cases the economic injury level is zero.

Dear Arvind

Your views are generally good but I am specifically interested in your view on parthenium grass and it's effects.

Does it qualified any of good points.

Let us deliberate.

Parthenium hysterophorus invades disturbed land, including roadsides. It infests pastures and farmland, causing often disastrous loss of yield, as reflected in common names such as famine weed. In some areas, heavy outbreaks have been ubiquitous, affecting livestock and crop production, and human health. Allergic reactions to the pollen and plant dust of parthenium weed are causing major health problems.

But like many weeds and pests that have been introduced into new areas, it is very bad in the new area but an essential component in the food web in its native area. The phrasing of the question is key. As a generic question about the value of weeds the answer must be that they have an ecological role. In a question about a specific weed that has been moved out of its native area then the answer may be that it has no value. Likewise, as long as eradication efforts are confined to the non-native environment all is good. If those efforts result in extinction then you will cause great harm to the ecosystem where the weed is native while saving the ecosystem where the weed was introduced.

Very interesting question....

True, it is always necessary to manage the weed plants...

Why we are called plant as weed?...because that plant might be suppressing the crop or competing for nutrients, light, water, space and other natural resources in question...it means plant is directly or indirectly influencing crop growth and productivity... two words are accurate to define weed that is place and time...if any of the plant growing out of their place usually in economic crop field and out of time means during the crop growth cycle...eradication may or may not be a suitable word as suitable word is management....

If phalaris minor is growing in fallow land where no crop is bring taken for cultivation then phalaris minor though called as weed but at this situation it is not desirable to control it as it is not involving in crop performance....