Biotechnology in Conservation of Agricultural Environment
K. Sarala, Senior Scientist (Biotechnology) Central Tobacco Research Institute, Rajahmundry-533 105, A.P.
Increase in crop yield in agriculture in 1960s, in India, was mainly due to introduction of new high yielding varieties. This has necessitated intensive use of agro-chemicals (mineral fertilizers and pesticides). However, the increase in agri-inputs was not directly proportional to the yields realized. During 1946-1965, the chemical (fertilizers and pesticides) input consumption was 87.0 Million Metric Tonnes (MMT) and food production 90 MMT; where as in 1998-2001, chemical input consumption was 1000 MMT and food production 220 MMT. Thus, when compared to 1946-1965, a 12 fold increase of chemical fertilizer consumption resulted in only 2.5 fold increase of food production. These figures indicate that for each unit of additional food produced higher amount of chemical inputs were utilized (Alvares, 1999; http:/indiabudget.nic.in; www.photius.com). The added inputs especially inorganic fertilizers, pesticides and weedicides have led to environmental problems. Progressive mechanization and mono-culture are other features that were added to Indian agriculture scenario after green revolution.
As a consequence of intensive agriculture natural resources were depleted, soils lost their natural fertility, soil microflora affected adversely, soil erosion increased and sudden and frequent apparition of new pests and diseases occurred. Excess use of fertilizers also spoiled soil health and adversely altered nutrient dynamics in the soil. Indiscriminate and injudicious use of pesticides contaminated the surrounding atmosphere, killed beneficial insects, soil micro flora and fauna and contaminated ground water. In addition to pest resurgence and new biotype / pest development minor pests became major pests and pests developed resistance to regularly used pesticides. All these things disturb the environmental balance. The present paper deals with applications of Biotechnology in alleviating these affects.
Plant biotechnology is a revolutionary new field that harnesses the knowledge gained over more than half a century of basic plant research to the benefit of man kind. Agriculture is already realizing huge benefits from improved crops developed through biotechnology, which shows remarkable resistance to insect damage, markedly reduced dependence on herbicides, improved yield levels, higher photochemicals etc.
Agricultural biotechnology helps to alleviate the above ill effects of intensive agriculture through the development of bio-fertilizers, bio-pesticides, and disease and pest resistant varieties, and genotypes with higher water and nutrient use efficiency. All these aspects are discussed below.
Some alternatives to the use of mineral fertilizers are green manures, composts and bioearths, earth worm manure, crop and agro industrial residues and biofertilizers.
The native soils harbor microorganisms like bacteria, actinomycetes, fungi, algae, protozoa etc. These microorganisms enrich the nutrient quality of soil. Plants have a number of relationships with these fungi, bacteria, and algae. Few of the useful microorganisms can be produced in the form of Bio-fertilizers and added to the soil for improving the soil fertility and plant nutrient uptake.
Bio-fertilizers are the preparations containing live or latent cells of efficient strains of nitrogen fixing, phosphate solubilizing or cellulolyotic micro-organisms used for application to seed or composting areas with the objective of increasing the numbers of such micro-organisms and accelerating those microbial processes which augment the availability of nutrients that can be easily assimilated by plants(Ghosh, 2003). Some of the microorganisms being used as biofertilisers and their uses are given in Table 1. Table 1. Biofertilizers and their utilities S.No.Bio-fertilizerutility 1.RhizobiumFix atmospheric nitrogen in symbiotic association with legume plants forming nodules in roots (stem nodules in Sesabaniam rostrata) 2.AzotobacterBeneficial to cereals, millets, vegetables, cotton and sugarcane. It is free living and non-symbiotic nitrogen fixing organism produces certain substances good for the growth of plants and antibodies that suppress many root pathogens 3.AzospirillumNitrogen-fixing microorganisms beneficial for non-leguminous plants also produce growth promoting substances. 4.Blue Green Algae (BGA)Photosynthetic nitrogen fixers and are free living. Found in abundance in India. Add growth-promoting substances including vitamin B12, improve the soil’s aeration and water holding capacity and add to biomass when decomposed after life cycle. 5.AzollaAn aquatic fern found in small and shallow water bodies and in rice fields. It has symbiotic relation with BGA and can help rice or other crops through dual cropping or green manuring of soil. 6.Phosphate Solubilizing Bacteria(PSB) The PSB are life forms that can help in improving phosphate uptake of plants in different ways. The PSB also has the potential to make utilization of India’s abundant deposits of rock phosphates possible, much of which is not enriched
In India, total Biofertilizer production capacity of public and private sector units is 18200 tonnes and total estimated Biofertilizer production is 10,000 tones during 2006-07. The Biofertilizer demand for the year2011 has been estimated at 30,000 tonnes by a recent expert committee constituted by the Ministry of Chemicals and Fertilizers. This clearly indicated that there is a large scope of biofertilisers industry in India.
Integrating biologicals in pest management
The adverse affects caused by excess use of pesticides can be reduced by following integrated pest management (IPM) approach i.e. integrating chemicals with biologicals in the pest management. This approach not only reduces the crop losses due to pests but also make agriculture more sustainable. Botanical pesticides and biocontrol agents offer immense scope in IPM
Biopesticides are biorational and help to create Natural epizootics. They are inherently less harmful than conventional pesticides. They suppress, rather than eliminate, a pest population. Biopesticides are effective and often quickly biodegradable, present no residue problems and mostly self perpetuating.
Biopesticides, particularly microbial biopesticides, have virtually all the health safety and environmental properties that one would desire in a pesticide. The ecological fallacy and the individualistic fallacy need to be studied in detail.
Microbial insecticides are come from naturally-occurring bacteria, fungi, viruses (Ramarethinam, 2006). Various details of biopesticides including mechanism, pests and crops etc. are given in Table 2.
Table 2. Biopesticides their source and mechanism in pest control
Biopesticide type SourceNature/organismMechanismUsed againstCrops benefited Natural productPlant-Neem Vitex GarlicBiochemicalsAntifeedant, growth regulation, oviposition and mating disruptionInsect pestHorticultural, plantation and plain crops MicrobialsBacteria Bacillus thuringiensis(Bt) InfectionInsect pests B. sphaericus, PseudomonasAntibiosisDisease VirusNuclear polyhedrosis viruses, Granulosis virusesInfection resulting in epizooticsInsect pest FungiBeauveria, Metarhizium, Paecilomyces, NomuraeaInfection resulting in epizooticsInsect pests Trichoderma GliocladiumAntagonism and AntibiosisFungal disease of plants ProtozoaNosema, Thelohania, VairimorphaEpizooticsInsect pests PheromonesPheromonesBiochemicalsMating disruption, lure and kill, or insect monitoring strategiesInsect pest Genes or Plant-pesticide :Desired genes from a known sourceBiochemicalsConfer tolerance of herbicide application or resistance to attack by viruses or insectsInsect pest and disease
Market potential of biopesticides in India
The domestic market of biopesticides is in infant stage still – despite decades of existence, biopesticides are considered as marginal products. Virtually bereft of buyers and sellers. Awareness about the advantages of biopesticides is abysmally low as compared to the west,” this is affecting their demand adversely. Manufacturers claim that the projected demand for biopesticide has failed to become a reality. Rough estimates by the experts indicated a less than 2 per cent market share for Biopesticides in India (Agriculture today, Jan, 2005).
Agricultural Biotechnology – Varietal Development
Using different biotechnological techniques varieties having higher yields, disease and pest resistance, fertilizer responsiveness, herbicide tolerance, higher water/fertilizer use efficient, drought resistance etc can be developed. Biotechnology offers various advantageous over conventional breeding in developing crop varieties (Table 3). It employs novel technologies for creating variability, gene transfer, selection of segregating generations, transgenic development etc. Time taken for breeding a variety can be substantially reduced through biotechnology approach. Gene silencing (“switching off” of a gene by a mechanism other than genetic modification) and gene attenuation (to stop translation of an mRNA of a gene when certain conditions are not met) strategies can be employed to develop desirable genotypes.
Table 3. Agricultural Biotechnology vs. conventional breeding in varietal development
S.NoParameterAgricultural BiotechnologyConventional Breeding 1Creation of variabilitySomaclonal variationCreate through hybridization of parents Gamato clonal variation Proto clonal variation In vitro mutations 2Gene transferInter specific Mostly intra-specific, rarely inter-specific Inter generic 3Selection In vitro selectionPhenotypic selection Marker assisted selection 4GenesIsolated genesUses available variability Synthetic genes 5Gene transferAgro bacterium MediatedCrossing Gene gun Protoplast Fusion 6Time taken for breedingCan be reducedFairly long 7Trait expressionGene silencingCan’t be used Gene attenuation etc.,
Biotech crops in the world
Number of crop varieties were developed using various biotechnological approaches. Among them, Flavr savr tomato is the first transgenic crop released for commercial cultivation in USA in 1995. Later, number of pest and disease resistant varieties were released in cotton, maize, potato, soybean, tomato etc in different countries. Most of the cases the genes are cry genes conferring resistance to lepidopteron pests followed by viral genes. Pest resistance varieties substantially reduce the amount of pesticide use, there by avoids environmental problems.
From 1996-2007, global biotech crop area increased from 1.7 m ha to 114.3 m ha. 23 countries are growing biotech crops viz. soybean, cotton, maize and canola, 13 biotech mega countries growing 50,000 ha or more of biotech crops. The area covered by biotech crops in industrial countries is more compared to developing countries. These statistics indicates the increased awareness of the world farmers about biotech crops (James, 2007).
Biotech crop status in India
Many public and private sector institutions are involved in the development of biotech crop varieties in India. Biotechnology research in India is funded primarily by government agencies such as DBT, CSIR, ICAR and ICMR.
Regulations in India
Development and cultivation of transgenic varieties are raising many environmental concerns. In view of this, transgenic variety in any crop is released once it satisfies all environmental concerns. Before release they will be thoroughly tested for their effect on soil flora and fauna, allergenicity, toxicology etc. In India, Department of Biotechnology in Department of Science and Technology and Ministry of Environment and Forests are responsible for implementing bio-safety regulations with in the country. The regulation of genetically modified organisms (GMOs) in India has been subjected to the rules framed by the Ministry of Environment and Forests (MOEF) in 1989(GOI, 1989). These rules, which were part of the Environmental (Protection) Act of 1986, defined implementing structures for conducting research and for the commercial applications of GMOs. Department of Biotechnology formulated guidelines for conducting research in transgenic plants (GOI, 1990 1994 and 1998).
Govt. of India has evolved regulatory mechanisms for the development and evaluation of Genetically Modified Organisms (GMOs). Various bio-safety committees, starting right from the institute where the research is going on to District and State, are in operation to monitor the safety of GMOs. GM crop regulatory structure in India consists of the following six committees. First three are under the Department of Biotechnology (DBT), next one under the MOEF and the last two operate at sub-federal levels closer to the actual site of GM crop field trials.
Recombinant DNA Advisory Committee (RDAC): Reviews developments in biotechnology at national and international levels and recommends suitable and appropriate safety regulations
Review Committee on Genetic Manipulation (RCGM): Monitors safety-related aspects of ongoing research projects and activities involving genetically engineered organisms.
Institutional Biosafety Committee (IBSC): Constituted by the institution conducting research that handles micro-organisms/genetically-engineered organisms.
The Genetic Engineering Approval Committee (GEAC): Based in MoEF and gives approvals for activities involving large-scale commercial use and release of hazardous micro organisms including imports of GMOs and recombinants
The State Biotechnology Coordination Committee (SBCC): Nodal agency at the State-level to assess damages, if any, from the release of GMOs.
The District Level Biotechnology Committee (DLC): Monitors safety regulations in installations engaged in the use of GMOs and hazardous substances at District level.
Steps in GM plant commercialization process:
In India, a transgenic variety is developed under the close supervision of different regulatory bodies’ right from lab and greenhouse experiments to its approval for commercial production (Table 4). This elaborated exercise helps to assess their possible impact on environment. In case of any adverse impact that particular line will be withdrawn before release. Only lines that don’t have any impact will be considered for release based on their agricultural advantage.
Table 4. GM plant commercialization process
Steps in GM plant commercialization process Data generated at this step(more can be requested if needed)Who approves 1. Lab & greenhouse experiments Rationale for development of GM plant Cloning strategy Characteristics of expression vectors, inserted genes, promoters Transformation/cloning method Genetic analysis of transgene Biochemistry of expressed gene Compositional analysis Description of host plant, geographical distribution in country of origin, Back crossing duration, seed setting characteristics, germination rates, phenotypic characteristics, target gene efficacy tests Observations about implications of toxicity & allergenicityIBSC risk category I & II RCGM risk category III 2. Contained open field trials & generation of biosafety data Germination rates & phenotypic characteristics Studies of gene flow, invasiveness, weed formation Implications of out crossing Susceptibility to diseases & pests Toxicity & allergenicity of plants/fruits/seeds Food/feed safety evaluation in animalsIBSC/RCGM 3. Multi-location trials Agronomic advantageRCGM/GEAC 4. Large-scale field trials Agronomic advantageGEAC 5. Environmental, food & agronomic approval GEAC 6. Variety registration* Agronomic advantageICAR, National and State Seed Quality control agencies 7. Approval for commercial production GEAC
Biotech crops cultivated in India
On 26th March 2002, Genetic Engineering Approval Committee (GEAC) for the first time approved three Bt cotton hybrids (MECH 12 Bt, MECH 162 Bt and MECH 184 Bt) of MAHYCO for commercial cultivation in India. RCH2 Bt hybrids of Rasi seeds were approved on 1st April 2004 in Central and Southern part of India.
Bt-cotton was first planted in India in 2002. Following its success, the area under this crop and the number of farmers who adopted this technology increased significantly from year to year as shown in the Table 5 below:
Table 5: Area under Bt-cotton in India (2002 to 2007) YearTotal cotton area in hectaresBt-cotton area in hectaresBt-cotton area in acres% area occupied by Bt-cottonNo. of Bt-farmers 200287,30,00029,00072,0000.320,000 200376,70,00086,0002,13,0001.175,000 200476,30,0005,53,00013,66,0007.33,50,000 200589,20,00012,67,00031,31,00014.210,00,000 200691,58,00038,00,00094,00,00041.523,00,000 200794,00,00062,00,000*153,20,00066.038,00,000 Source: http://www.cbd.int/doc/external/mop-04/fbae-cotton-en.doc Thus, in about 6 years, the area under Bt-cotton has increased by more than 210 times to record 6.2 m ha and the number of Bt-farmers by 190 times to reach 3.8 m in 2007. Further, Bt-cotton has occupied 66% of the 9.4 m ha of the total cotton area in India in 2007.
Associated Chambers of Commerce and Industry India (ASSOCHAM) and IMRB International study on Bt cotton in India revealed that cotton farmers have earned an additional income of Rs 7,039 crore in 2006 after a 50 per cent increase in yield due to use of Bt cotton seed. Introduction of two stacked genes into Bollgard II Bt cotton has saved pesticide use to the tune of Rs 1,600 per acre. Bollgard II Bt cotton has the advantage of controlling both bollworms and the sucking pest, Spodoptera, while Bt cotton (with one gene) controls only bollworm. Bollgard II Bt cotton was allowed for commercial cultivation in central and western India in 2006. In view of the increased crop yields of BT cotton, India turned into a net cotton surplus country from a net importer in four years.
Number of pesticides sprays and amounts spent pesticide per acre were reduced when Bt cotton and Bollgard II Bt cotton were cultivated. Additional profit of Rs. 7,757/- and Rs. 10,352/- per acre, respectively, were realized by Bt cotton and Bollgard II Bt cotton over conventional cotton varieties (Table 6).
Table 6. Advantage of Bt cotton over conventional varieties
Cotton varietyNo.of pesticide spraysAmount spent on pesticide per acreProfit /acre* Conventional cotton -Rs. 2,900Rs. 4,784 Bt cotton (with one gene, cry 1 Ac)4.6 times less than conventionalRs. 2,000Rs. 12,541 Bollgard II Bt cotton (with Cry I Ac and Cry 2 Ab genes) 2 times less than Bt cottonRs. 1,300Rs. 15,136
* Bt seeds are 2.5 times costlier than conventional seeds
The results of other five studies conducted by public institutions and published recently are summarized in the table below to exemplify the benefits (Manjunath, 2008). Table 7 : Results of studies carried out by neutral agencies on the performance Of Bt-cotton in India
Publication / ParametersBennett et al., 2006Gandhi & Namboodiri (IIMA), 2006Qaim, 2006ICAR, 2006Ramgopal (Andhra Univ.) 2006 Period studied2002 & 200320042002-0320052005 Yield increase45 – 63%31%34%30.9%46% Reduction in chemical sprays3 to 139%6.8-4.2(50%)-55% Increased profit50%88%69%-110% Average profit / hectare-$250/ha$118/ha-$223/ha The results reveal that a) increase in cotton yield ranged from 30.9 to 63%, b) reduction in chemical sprays was from 39 to 55% and c) increase in profit to farmers ranged from 50 to 110% equivalent to about US$ 250 (Rs.10, 000) per hectare over the non-Bt cotton. It is reported that the average cotton yields in India which was 308kg/ha in 2002, prior to introduction of Bt-cotton, increased to 560kg/ha in 2007 (at least 50% of increase is attributed to Bt technology). Similarly, the national cotton production increased from mere 15.8 million bales in 2002 to 31.0 m bales in 2007. Exports of raw cotton, which was 0.9 m bales in 2005, increased to 4.7 m bales in 2006 and touched 4.8 m bales in 2007. Further, Bt-cotton contributed US$840 million or more to National farm economy. The studies carried out on Bt-cotton both before and after commercialization have clearly shown the following benefits: a) Higher cotton yield owing to effective control of bollworms, b) drastic reduction in the application of chemical insecticides for bollworm control, c) higher profit to farmers and d) conservation of biological control agents and other beneficial organisms. Thus, there have been social and economic benefits and intangible environmental benefits. The ever-increasing demand for Bt-cotton seeds is a clear reflection of farmers’ confidence in this technology and its benefits.
Use of bio-fertilizers, bio-pesticides and transgenic varieties in agriculture are showing increasing trend. Use of these things will reduce the utilization of chemical pesticides and pesticides; there by the harmful effects they produce will be reduced. Further increase in these eco-friendly biotech derived agri-inputs is essential to alleviate the environmental issues raised in conventional agriculture. References: Agriculture today (Jan,2005). The National Agricultural Magazine, Published by New Delhi. Alvares, C. (ed.) (1999) The organic farming source book. Published by The Other India Press/Third World Network, Goa (India). 366 p Bennett, R. et al., 2006. Farm-level economic performance of genetically modified cotton in Maharashtra, India. Review of Agricultural Economics, 28: 59-71. Gandhi, V. and Namboodiri, N.V., 2006. The adoption and economics of Bt-cotton in India: Preliminary results from a study. Indian Institute of Management (IIM), Ahmedabad, India. Working paper No. 2006-09-04, pages 1-27, Sept. 2006. Ghosh, Nilabja 2003. Promoting Bio-fertilizers in Indian Agriculture. Institute of Economic Growth Discussion Paper Series No. 69/2003. Delhi, India. GOI. 1989. Rules for the manufacture, use, import, export and storage of hazardous microorganisms/genetically engineered organisms or cells, issued by the Union Ministry of Environment and Forests, Govt. of India (Notification No. G.S.R. 1037 9E) dated 5 December 1989. GOI. 1990. Recombinant DNA safety guidelines. DBT, Union Ministry of Science and Technology, Govt. of India, p. 90. GOI. 1994. Revised guidelines for safety in biotechnology. DBT, Union Ministry of Science and Technology, Govt. of India. GOI. 1998. Revised guidelines for research in transgenic plants and guidelines for toxicity and allergenicity evaluation of transgenic seeds, plants and plant parts. DBT, Union Ministry of Science and Technology, Govt. of India, p. 92. ICAR (Indian Council of Agricultural Research), 2006. Frontline demonstrations of cotton – 2005-06. Mini Mission II, Technology Mission on cotton. ICAR, New Delhi. James, C. 2007. Global Status of Commercialized Biotech/GM Crops: 2007. ISAAA Briefs No. 37, 225 pp. ISAAA: Ithaca, NY. Manjunath, T. M. (2008) Position Paper on Indian Bt cotton. Bt-Cotton in India: Remarkable Adoption and Benefits. http://www.cbd.int/doc/external/mop-04/fbae-cotton-en.doc. Manjunath, T. M. 2007. Q & A on Bt-Cotton in India. Answers to More than 70 Questions on All Aspects. All India Crop Biotechnology Association, New Delhi, 78 pp. Qaim, M. 2006. Adoption of Bt cotton and impact variability: Insights from India. Review of Agricultural Economics, 28: 59-71. Ramarethinam, S (2006) Conference on Agrochemicals. January 12-13, 2006, Mumbai. Speeches and Presentations-2006: FICCI (http://www.ficci.com/media-room/speeches-presentations/2006/speeches-2006.htm). Ramgopal, N., 2006. Economics of Bt-cotton vis–vis traditional cotton varieties – Study in Andhra Pradesh, Agro-Economic Research Centre, Andhra University, Andhra Pradesh.
Auther: K. Sarala, Senior Scientist (Biotechnology), Central Tobacco Research Institute, Rajahmundry-533 105, A.P.