Why its is importance to conserve genetic resources.......

Importance of Plant Genetic Resources to Crop Breeders.

Abstract

                Plant genetic resources are the gene pools of the plants and they play an important role in improving production and quality of food. For improvement of any crop it needs lot of germplasm with variation. This is used to bring the desirable changes in the cultivable cultivars. To breed the varieties with resistance against the biotic and a biotic stresses it is must to have the good source of germplasm. Due to urbanization many traditional cultivars are on the way to extinct so it has become necessary to conserve the natural varieties for future use.  Ex-situ and in- situ are two different  kinds of conservations system where plants are grown out of natural and in natural habitat respectively. Fast growing human population put forth the  challenge to produce food at higher rate. Many institutes like ICRISAT, have larger gene bank and they contribute significantly in production of agricultural crops. Despite of some limitations PGR still remain important factor in crop improvement. Besides this biotechnology is considered as a ray of hope.

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Agriculture has always been the major profession for the many people of the world since times immemorial. In order to take qualitative and quantitative production from the field the farmers have to consider many important factors viz. planting material, seed quality, land, cropping pattern, intercultural practices, crop protection methods, marketing etc. Among all these, the more importance is given to the pure and genetically fulfilled plant material. Before few centuries, the growing food to feed per capita was not an issue, but today on the eve of new millennium it is a challenge before the farmers and scientists to produce the food to feed the fast increasing population with the rate of160 people per minute. Approximately more than 90% of the population is living in developing countries where agriculture is a main profession but still there are many hurdles to achieve the desired food production. It is estimated that we need to produce food during coming 40-50 years as we had produced since the evolution of agriculture and of course we are now in the race between growing population and food production ( cropwildrelatives.com)   

                                                  Growing populations and pressure for social and economic development are leading to increasing rate of destruction and degradation of natural habitat, including forests and woodlands ( J.P. Lanly, FAO). As more emphasises is given to the  urban development rather than the agriculture, in most of the countries it is causing  loss of genetic material which is considered an important and a key element for adaption and improvement of plant species under cultivation. Besides this less resources, including financial and manpower are also overcoming a major constraints in field of production. Plant genetic resources are associated with the different levels of diversity that exist in nature, from ecosystem to species, population, individuals and genes.(R.H. Kemp, G.Namkoong and F.H. Wadsworth). The conventional agriculture would be the primary option while considering the different plans to produce food at higher rate and for the foreseeable future. According to the prediction made by International Food Policy Research Institute, the consumption of rice and wheat in developing countries will account around 96% and 60% respectively by year 2020. It will play a major role in feeding the poors of those nations. This prediction shows that how genetic material of wheat and maize will help to meet their requirement in developing countries. 

                                                  As per Agrodictionary.com the plant genetic resources are defined as, the gene pool of plants, especially the plants which are regarded as high value to human beings for food or pharmaceuticals. The genetic resources are always been considered as one of the important constituents of natural(specially Agro) biodiversity. The Plant genetic resources includes primitive forms of cultivated plant species and landraces, modern cultivars, breeding lines and genetic stocks, weedy types and related wild species ( IPGR 1993). Due to introduction of new varieties in agriculture, urbanization, many species are on the way to extinct, so the PGR are vulnerable and finite to losses because of these reasons. The PGR helps to provide the basic raw material to plant species improvement and ultimately its production.

 How to conserve Plant genetic resources?

The immense importance has been given to the conservation of plant species especially wild ones, germplasm for the future use and different kinds of conservation systems i.e in situ and ex situ conservation.

In- Situ method of conservation.

In situ type of conservation is like ‘on-site conservation’. The desired plant species are grown and conserved in natural habitat, for example forest genetic resources. During this process the plant species are protected from their natural predators. The main advantage behind the in situ conservation is that, it helps in maintaining the population in the surrounding where they have developed with their original and distinctive properties. Besides this it help the plant species to adjust and adapt with their own environment. Most of the wild life and livestock conservation is also based on this kind of conservation. And in other hand it helps to enhance the scientific knowledge of production technology of particular native and traditional varieties.

Ex situ conservation.

Ex- situ kind of conservation also called as “off-site conservation”. Unlike the in situ conservation, the plants species are grown outside of their natural habitat. It means the plant species of particular variety are introduced to different climate, geographical location where they never have grown before.  Ex- situ conservation comprises one of the best and oldest methods of conservation. Some laboratory methods are also involved in ex situ conservation.

                  Botanical gardens are the best example of this kind of conservation. Keeping the educational view in the mind, many species are introduced from different parts of world. Ex- situ conservation works where in-situ is not possible and this would be the major advantage of ex- situ conservation over in situ. But some time it becomes a challenge before man to transfer the plant species to new environment without harming them. In addition to this in many cases it is impossible to recreate the habitat as a whole. Ex- situ type of conservation are often found costly. Seed bank and germplasm are another option to conserve the endangered plant species. The term seed bank sometimes refers to a cryogenic laboratory facility in which the seeds of certain species can be preserved for up to a century or more without losing their fertility. It can also be used to refer to a special type of arboretum where seeds are harvested and the crop is rotated.( Encyclopaedia).

Showy Indian clover, Trifolium amoenum, is an example of a species that was thought to be extinct, but was rediscovered in 1993^[4] by Peter Connors in the form of a single plant at a site in western Sonoma County.^[5] Connors harvested seeds and grew specimens of this critically endangered species in a controlled environment.

Germplasm Collection and Conservations.

   Germplasm is important to access the relationship between the genetic resources and agricultural production. Germplasm with genetic abnormalities are important to plant breeders for specific purposes and also they are widely used in basic research programmes at different research institutes. The International crops Research Institute for the Semi Arid Tropics(ICRISAT) is one of the 15 CGIAR institutes( Consultative Group on International Agriculture Research) which  has established its own  genetic resources for the purpose of assembly, characterization, evaluation, maintenance, conservation, documentation and distribution of germplasm of sorghum ( Sorghum bicolour), pearl millet ( Pennisetum glaucum). chickpea ( Cicer arietinum), pigonpea (Cajanus cajan), ground nut (Archis hypogaea)etc (HD Upadhya).  ICRISAT was established in 1972, and effort were made to assemble the germplasm of its mandatory crops that existed with various research institute in India and other countries (Journal, ICRISAT 2008).

                           The fundamental objective of collecting PGR is to capture the maximum amount of genetic variation in the smallest number of samples.( Marshal and brown 1975). The development of efficient strategies depends on the extent of available information on the type of genetic variation in target population and their distribution in the target geographical region(Allard1970).Current collection at ICRISAT shows 70-80% diversity. The Geographical information system (GIS) is used to analyse available diversity and also it facilitate identification of gaps to launch targeted collections. At present in ICRISAT gene bank conserves 118,882 accessions of five mandate crops and six small millets from 144 countries. ( HD Uppadya)

Germplasm holding in ICRISAT genebank.

Crop                   Active collection            Base collection              Accessions held in trust

Sorghum                37,904                          34,313                            36,771 Pearl millet            21,594                          20,343                             21,563 Chickpea               20,140                           16,977                             17,124 Pigeon pea            13,632                           11,794                             12,389 Ground nut            15,419                           12,640                             14803 Finger millet           5,949                            4,620                                 5,949 Foxtail millet          1,535                              1,054                               1,535 Proso millet            842                                 576                                    835 Little millet            466                                  384                                   462 Kodo millet             658                                 630                                   656

Barnyard millet    743                                    487                                     743 Total                    118,882                             103,818                            113,830

  The natural resources in the earth are very finite and vulnerable. Many countries have pledged to stem the rapid loss of biodiversity and sustain these vital resources for the present and future generations. The research instaurations have created the plant genetic diversity in farmer’s field since many years and it is complemented by diversity present in wild relatives of the crop species.

                                          Adequate characterization for agronomic and morphological traits is necessary to facilitate utilization of germplasm by the breeders( HD Uppadhye). To achieve this, germplasm accessions of all crops are characterized for morphological and agronomic traits over the years. It is necessary to screen the genetic material against biotic and abiotic stress and it is done by scientist team. Characterization of germplasm is nothing but the recording of distinctly identifiable heritable characteristics. Objective behind the characterization of germplasm is

§  To describe and establish the diagnostic of conserved germplasm.

§  To classify them properly.

§  To develop the interrelationship between the traits and cultivars.

§  To identify the accessions with agronomic traits.     

It is also an important to regenerate the germplasm as the seed loose its viability even though under favourable storage conditions.Germplasm is generally conserved  in the form of seeds to maintain the integrity of the material conserved to the highest standards over a long period of time. The standards must be set on the basis of scientific knowledge with latest technologies for the proper storage and handling of seed in seed bank.In the table given above at ICRISAT, India, the active collections are kept for medium time period in aluminium plastic cans at 4 ºc, and whereas the base collection are kept for long time period in vacuum aluminium foils at -20 ºc.( IRISAT). Documentation is a necessary for efficient and effective use of germplasm in any gene bank. Information always play an important role in germplasm conservation and therefore the correct documentation of evaluation and characterization is necessary.     

Contribution of  wheat genetic resources.

Wheat is grown globally and it is consumed throughout the world. The genus of wheat “Triticum ”was originated 10,000  years ago in middle east (cropwildrelatives.org). Thousands of wheat species were collected and at present they are stored in different genetic resource centres and one of them is at Mexico (CIMMYT). Some of the studies during collection are attempted to estimate their contribution to wheat improvement. The role of genetic resources in wheat improvement was examined by Chapman(5) but he found it difficult to estimate it. He made a conclusion that those material were used in approximately 10%  of all crosses based on the pedigree of recently released cultivars. The CIMMYTS also has taken an effort to develop a full databases of global wheat genetic resources. The study found that number of different landraces in pedigree of modern wheat are increased steadily since last 30 years. Going beyond rather general and poorly defined contributions to modern varieties, several specific genes that have made major impacts on wheat can be directly traced to contributions from genetic resources. Till date it is found that the fungal pathogens has been responsible for many plant diseases, for example rust pathogen which causes major crop failure in almost every season. From genetic resources many genes have been found with resistance to the plant diseases.  (Source- www.cropwilevarity.com).

                    Since past some years the trend of the application of intellectual property rights (IPR) of  the agriculture products as well as plant variety has been increasing. it is treated as a global progress. In 1983, Food and Agricultural organization (FAO) established the international undertaking on plant genetic resources with view to protect them. The rule of free interchange of germplasm was subscribed for the “heritage for mankind”. To include the compensation and ownership of genetic resources, that undertaking was again modified in 1989 and 1991.

                   Many examples can be quoted to describe the role of plant genetic resources in the improvement of present (Modern) cultivar. The biotechnology could substantially enhance this use e.g.the molecular genetics allows the routine analysis of any characteristics of interest. Under the process of fingerprinting, DNA markers have been used to characterize the germplasm and it helps to evaluate the genetic relationships among the diversity. Besides this it also provide the information about ecology, population genetics and evolution.

                         In 17^th century due to industrial revolution, the overall face of traditional agriculture was changed. Agricultural productivity could have become possible because of the work of Mendel in the field of genetics but the traditional cultivars were replaced by  the modern varieties. Challenge came before us to increase the agriculture food productivity to meet the food requirement of fast growing population. Plant genetic resource stored in different part of world would have become the principle way to enhance the food productivity. Most of the genetic resources had resistance power against pest disease and harsh environment. In fact in many research programme the PGR were not introduced by researchers because of the difficulty in evaluation of materials with respect of height, growth and other morphological characters of plant. Despite of this limitation they were remain important factor in plant improvement. The hopes are kept towards the biotechnology to overcome the limitation. Biotechnology is the tool to use the genes governing the desirable characters to induce the qualitative changes and also the resistance against the stresses from wild species.

                                       Only Plant genetic resources or any single technology will not help us to produce healthy agriculture production. To face the enormous challenge of food production to growing population, we need to work with all different technology with keeping PGR as an important factor. It is also important to conserve the wild species for future use. This is a time to commit ourselves to feed our future generations with healthy and eco friendly food.

  

                                          

References.

·         H.D. Upadhyaya, CLL Gowda

·         Cropwildrelatives.org

·         Plant genetic resources management:  Journal, ICRISAT India.

·         Conservation of genetic resources in the tropical forest management.

                               Principle and concepts, by FAO.

                       

                        

                        

                  

Why one should think of organic farming.......?

Agriculture has always been the major profession for the many people of the world since times immemorial. Before few centuries, the growing food to feed per capita was not an issue, but today on the eve of new millennium it is a challenge before the farmers and scientists to produce the food to feed the fast increasing population with the rate of160 people per minute. Majority of the population is living in developing countries where agriculture is a main profession but still there are many hurdles to achieve the desired food production. It is estimated that we need to produce food during next 40 years as we had produced since the evolution of agriculture and of course we are now in the race between growing population and food production, and now it has become a dream of every agriculturist and agricultural scientist of the world to produce a qualitative and quantitative food production in a less area than what it was supposed to be. Since the evolution of agriculture the conventional farming system has always remain beneficial to producers in terms of production and economic. “The revolution after the post war has changed the entire face of agriculture. The introduction of farm based tractor closely by that of synthetic fertilizers, pesticides and factory farming of livestock. There was a desperate need for food in the recovering economics of the 1940s 50s and 60s. And farmers everywhere were encouraged to rely increasingly on synthetic inputs and intensive production methods in order to maximize the yield and quality.” (Letterick et al. 1999) Therefore it shows us that the conventional and intensive farming system has played an important role in crop production and labour efficiency. With the use of such intensive farming system, many environmental issues were raised which includes soil fertility, and environmental sustainability. Thus the organic farming system was the alternative option before the producers. However organic production can’t meet the total requirement of food since it requires full awareness, sufficient knowledge and also lot of natural organic components to be used for increasing the soil fertility, plant protection...etc. It is not possible to have a production of required quantum in a stipulate period of time. On the other hand, in conventional farming system the intensive use of chemical fertilizers, chemicals, synthetic pesticides, monoculture has helped to obtain the desirable crop production everywhere. Besides this there is one circular argument in the aspects of “seed sowing”. Despite of all of these benefits of conventional farming system we cannot neglect its adverse effects over a soil fertility and environment sustainability.

According to The United States Department of Agriculture, organic farming is a production system which excludes the use of synthetically compounded fertilizers, pesticides, growth regulators and livestock feed additives, and therefore it has never ever had any adverse effects on soil, and on any other environmental aspects. “Organic farming took on a new lease of life during the 1980s not just in Britain but around the world”(Lamkin, Organic Farming, 1990) The farmers could perceive the importance of organic system since they realized the problems occurred due to over industrialization and excessive use of synthetic fertilizers. Objectives of organic farming are concisely expressed in the International   Federation of Agriculture Movements (IFOAM) and some of them are as follow:

1)      High nutritional quality food production in sufficient quantity

2)      Working with natural systems

3)      To encourage and enhance biological cycles in the farming system

4)      Maintenance of soil fertility for long term

5)      Maximize use of renewable energy sources

6)      To avoid all agricultural techniques those causes pollution

7)      To maintain genetic and bio diversity

8)      Consideration of the wider social and ecological impact of the farming system

Many factors in the recent years like pollution, soil erosion has brought kind and immediate attention towards the implementation of organic techniques. “Heavy agricultural reliance on synthetic chemical fertilizers and pesticides is having serious impact on health and environment” (Pimentel et al.2005). In The United States of America 90% of farmers rely on herbicide to control the weed. The most commonly used pesticide ‘Attrazine’is found in streams and ground water, and which is obviously would have had been be a serious issue( Pimentel,1993).

In 1862, Friedrich Albert Fallou wrote : “ There is nothing in the whole of nature which is more important than or deserves as much attention as the soil. Truly it is the soil which makes the world a friendly environment for mankind. It is the soil which nourishes and provides for the whole of nature; the whole of creation depends upon the soil which is the ultimate foundation of our existence” Besides this Soil has been given a place of mother in many cultures of the world. As a mother plays an important role in taking care of her child, a similar role is played by soil. Soil provides greater support to big buildings, houses, industries.  It also acts as a layer for road construction, which is one of the mean for transportation. It is therefore very hard to imagine about food production without quality soil. Agricultural yields are increased in last 50 years but this remarkable production could not become possible without paying cost. This cost has been paid by gradual reduction in organic matter levels in the soil and especially in the area where highly production obtained with the use of intensive conventional farming system.  As per to the Strutt report Modern Farming and the soil, published by Ministry of Agriculture, Fisheries and Food (MAFF) in 1970, some soils were suffered from low organic matter level and they were not expected to sustain the farming system imposed on them. Available nutrient and energy supplied by organic matter runs all biological activities of soil therefore biological activity of soils were declined by low organic matter level. The soil contains different organisms of different size and function and all of them play an important role in the metabolism of nutrients in the soil.

(Picture source- textbook organic farming by Nicolas Lampkin pp- 16)

Rapid loss of soil which we call as a soil erosion is the another factor responsible for loss of organic matter level from soil. The soil erosion is mostly accelerated by modern agricultural practices, and the estimated annual cost of public and environmental health loss related to soil erosion exceed $45 billion( Pimentel et al. 1995).  In organic farming system, crop rotation is followed with grass leys, green manuring and under sowing of crops such as maize; which significantly helps to reduce the soil loss. The best example can be taken of Reganold et al. (1987)  who compared the soils from conventional farm and another organic farm, the soil loss was found 16 cm greater on conventionally managed farm( please see the figure above). Even though the soil loss on organic farm was 5 cm but of course it was less than that of conventional farm. Many research studies have been conducted till date to carry out the comparison of the effect of organic and conventional farming system on different soil properties.  In Washington State, USA, the detailed study of two commercial wheat farms was made (Weilgart Patten 1982, Bolton, Jr  et al. 1985,Reganold  et al. 1987, Reganold 1988) .The organic farm was managed ideally without use of chemicals, chemical fertilizers with just limited application of pesticides for nearly 80 years, on the other hand the another farm received recommended rates of fertilizers and pesticides. In organic farm complex crop rotation was followed with the use of green manuring, cover crops as legumes. In contrast to this, the conventional farming system was followed with simple rotation system without green manuring. The following results were obtained.

1)      High organic matter was found on organic farm soil.

2)      High amount of active micro flora with better structures soil found on organic farm.

3)      Top 16 cm layer was found fertile in organic farm.

4)      This difference in top soil had attributed considerable soil erosion on conventional farm in between 1948 to 1985.

From these results it is clear that the organic system is more effective than conventional farming system in maintaining soil fertility, productivity, tilth of soil. “The ability of the organic farm to produce yields similar to those of neighboring conventional farms, even after almost 80 years of farming without chemical fertilizer, may be attributed in part to the reduction in soil erosion and maintenance of soil organic matter”(Reganold et al. 1987).

In New Zealand, Robertson (1984) too carried research a comparative study of soil properties, on two different market gardens out of them one was an organic market garden and another was a conventional market garden. On organic farm, the soil treatments included use of compost, poultry litter, biodynamic preparation 500, green manuring and on conventional farm the applications of nitrogen, phosphorous, potassium, and lime were made. Weed and pest control methods were of course non chemical on organic farm whereas chemical sprays were used to control pest and weed on conventional farm. The soil from organic farm had a higher organic matter with more earthworms, higher transpiration rate, more extractable phosphorous, potassium, magnesium, higher pH and water content. Soil properties were more favourable on organic garden as compared to conventional farm garden.

To fulfill the dream of quality production, producer has to undergo with many hurdles                 including soil quality, fertility, genetically pure plant material, seed availability, climate, market, pest disease...etc.  Out of all these hurdles the impact of pest and disease attack on crops is quite considerable and has greater effect on quality and quantity of food produce. Insects has always been a certain interrelation with the world, their population is more than that of humans!!!! Accordingly to the John Kent (1991) “Pesticides (or farm chemicals, agro chemicals or agvet chemicals) are those substances which are used to control, destroy, repel or attract pests in order to minimize their detrimental effects”. Different viruses, bacteria, fungi, weeds, insects, animal are referred as a pests and all these may reduce the production and affect the quality of the food produce. In organic farming system, major importance has been given on non chemical pest control methods. These methods often control use of biocontrol agents, nematodes, natural enemies, and natural insecticides for eg. Neem oil, neem seed kernel extract, neem powder. In contrast to this, in conventional farming system the recommended doses of chemical pesticides are sprayed. Chemical pesticides are having several disadvantages. After application of them over a crop they affect the nervous system of insect, affect the metabolism, pigment system, and affect the translocation of organic food by affecting the phloem. There are some benefits behind using the chemical insecticides, as they kill or repel the insect pest those causes the quality and yield of the food produce. Many of the chemical insecticides are economic. But while considering these benefits we cannot neglect the hazardous effect of chemical pesticides over a pests and crops since they cannot distinguish between pest and non pests and may become harmful to useful organisms. After spraying chemical insecticide they just kill any insects those come in their way. “Many of these early chemicals had disadvantages. They were often highly toxic, were very persistent, posing a threat to the environment, or they damaged the crops they were meant to protect.”(Kent 1991). They often leaves residual effect behind and these left residues in the food may contaminate poison to human, during spraying they may damage to the crop, environment and other livestock. Weather condition and the way of application of pesticide can affect the drift. While applying chemicals over the crops if they are applied in excess and their leaching may contaminate the irrigation water as well as ground water. It is very necessary to take prevention method while spraying the chemical pesticides otherwise it may affect adversely to the sprayer and may pollute the environment.

Table 1

2005 Global pesticide market by region ( figures in $ US Billion)

North America	8.60
Europe	8.74
Asia	8.16
Latin America	5.65
Rest of World	2.45
Total 33.6

Source: Allan Woodburn Associates/Cropnosis.

“The past ten years have been marked revival of interest in the biological method of insect control. It arose from a growing realization that supplements and alternatives to chemical insecticides are needed to overcome some of the faults and weaknesses now recognized as Inherent in the chemical method of pest control”.( Bryan. P. 1962, p-387). Many people, farmers, agriculture industries are now realizing the hazardous effect of chemical pesticides and therefore they are moving towards the adoption of biopesticides. Because of the public awareness, demand for biopesticides is gradually increasing in all over parts of the world.

Estimated sales of microbial and nematode biopesticides

	Sales Estimates ($)
	North America	Europe	Asia and Australasia	Latin America	Africa and Middle east	Total
Total Bt.	72.75	26.77	43.12	14.45	2.48	159.57
Other bacteria	15.20	2.60	11.58	0.65	0.10	30.13
Viruses	1.03	5.45	5.33	2.89	0.55	15.25
Fungi	11.76	2.17	11.52	22.16	0.49	48.10
Protozoa	0.05	0.00	0.02	0.00	0.00	0.07
Nematode	8.25	6.00	0.37	0.03	0.00	14.65
Total	109.04	42.99	71.94	40.18	3.62	267.77

·         Produce based on B. thuringiensis serotypes.  Source-  ( CAB reviews: Perspectives in Agriculture , Veterinary Science, Nutrient and Natural Resources 2007 no.51)

Now a days it has become a challenge before the growers to produce a qualitative and quantitative food for fast increasing population in many part of the world in due course of time.  The food scarcity would be the big issue and people will starve because of food. It is not only because of the availability of the food but also because of safety food.  From all above discussed points, it is clear that, total crop production to feed ever increasing world population is not practically possible with organic method alone, since it will take some time to change the cropping pattern from conventional to organic and again to change the mind set of farmers. So to meet the challenges of food production we have to set the Integrated Farming System. With the combined use of conventional and organic farming system, we can surely complete the target of food production.

References

Pimentel D, et al. 1995. Environmental and economic costs of soil erosion and conservation benefits. Science 267: 1117–1123.

Pimentel D.  2005.   Environmental and economic costs of the recommended application of pesticides. Environment, Development, and Sustainability. Forthcoming.

Regnold. J .P. , Elliott, L. F. and Unger Y.L. (1987) – Long term effect of organic and conventional farming system on soil erosion Nature 330 pp- 370-372.

Robertson, M.K. 1984. A Comparative Study of Soil Factors Affecting Plant Growth within a Set of Organic and Conventional Market Gardens. Diploma Thesis, Massey University, Palmerston North, New Zealand.

Lamkin, N.H., (1990) Organic Farming, Farming press.

Blake, F. (1994) Organic Farming and Growing.  The Crowood press.

Litterick, A.; Brenman, S.; Leifert, C.  Organic farming - its role in the new century.

Sixth International Conference on Kyusei Nature Farming. Proceedings of the conference on greater productivity and a cleaner environment through Kyusei Nature Farming, University of Pretoria, Pretoria, South Africa, 28-31 October, 1999 2001 pp. 15-25

Trends in applied biological control of insects,

By Brayan P. Beirne , 1962 p 387-400.

PESTICIDES IN AGRICULTURE

By John Kent ,Lecturer in Agricultural Protection, School of Agriculture, Charles Sturt University.

Wagga Wagga. NSW 2678. (http://www.regional.org.au/au/roc/1992/roc1992031.htm)

Kent, J. (1991). Education and training in farm chemical management. Proc. conf. Agriculture, Education and Information Transfer. Murrumbidgee College of Agriculture, 1991.

Web Supports.

http://www.takingroots.in/case_studies