Code No: TMS098 Price: Rs1400/- Category: Foods & Agriculture: Inputs to the Soil
Techno-Market Survey on Biopesticides: Executive Summary
The problem of pests on agricultural crops were known to man since adoption of crop husbandry in a systematic way. This awareness f problem led methods for their control. The current annual loss due to insect, pests and diseases in the agricultural sector is around Rs.15,000 crore and over 20 million man days are lost due to the vector borne diseases. The country is in no position to accept the loss of food grain caused by pests in the agricultural fields as well as the damage caused to stored grain of which losses by insects and pests are of most economic importance. Chemical means of plant protection occupy the leading place as regards their total volume of application in integrated pests management and diseases of plants. But pesticides cause toxicity to humans and warm-blooded animals. Therefore, there is a need to develop biopesticides which are effective, biodegradable and do not leave any harmful effect on environment.
Agriculture is the back-bone of Indian economy. Upto 70% of the population is engaged in farm sector directly or indirectly. Growing Indian population needs sufficient farm produce. Farming and the agriculture crops are susceptible t attacks by various kinds of pests in form of insects, fungus, bacteria or virus or weeds and control of these has become necessary to reduce losses to a minimum.
Heavy use of synthetic chemicals for pest control started from 1940s. Till then we were using natural insecticides namely rotenone from the roots of derris plant, and pyrethrum from the flower heads of a species of chrysanthemum.
After twenty years it was found that the level of synthetic pesticides were building and were not biodegradable and their harmful effects started coming out.
A study of the pesticides-use pattern in the country has revealed that cotton, which accounts for just 5 per cent of the cropped area, consumes about 52 to 55 percent of the pesticides. Rice grown over 24 per cent of the cropped area uses about 18 per cent, vegetables raised over 3 per cent area, about 14 per cent plantation crops covering 2 per cent of the area, 8 per cent and cereals, millets and oilseeds extending over 58 per cent of the area, 7 per cent. Sugarcane uses 2 per cent of pesticides and other crops grown over 6 per cent of the cropped area account for another 2 per cent. The per hectare consumption of pesticides in the country is far lower than that in some of the developed countries. But the number of chemicals that are sold in the country and the indiscriminate use of plant protection chemicals are matter of grave concern.
The first chapter describes the relevance of this study with supporting data. Although, demand for pesticides will continue to grow for agricultural production cannot be cut down but alternatives will have to be developed before pesticides targets human beings.
Indian agricultural strategy from mid-sixties has been mainly on fertilisers, irrigation and use of high yielding varieties. But the farmers ignore adopting some essential crop husbandry practices in crop production, as for example, non-adoption of pre-monsoon ploughing, synchronising sowing dates, rogueing, crop rotation and seed dressing. Other practices like growing continuous cropping, ratooning, growing alternate host crops in the same field year after year, excessive use of nitrogenous fertilisers and excess irrigation are still continuing which are aggravating pest problems. Farmers can achieve more than 80% relief from pest problems, if they strictly adopt cultural practices and seed treatment with agrochemicals. Seed treatment helps protect crops from seed and soil-borne pests in the early phase during and after germination.
This is not only cost-effective but also ensures optimum plant population per unit area and higher yields. For instance, wheat seeds treated with vitavax/bavistin @ 2 g/kg and 20 ml. Neem oil/Neem rich-I reduces loose smut infection upto 98%. Similarly, sorghum and pulses seeds treated with monocrotoophos @ 4 ml/kg. and 20 ml nedm oil/neem rich-I of seed reduces shootfly and stemfly incidence by 95%. Pre-monsoon ploughing helps reduce soil pest population through exposure to sun and predator birds. Bajra intercrop in groundnut helps reducing the incidence of leaf minor and sorghum bean combination helps in curbing the stem borer in sorghum and aphids in bean.
A chapter describes the pests, pesticides and various classifications used to understand chemical pesticides with respect to their target or with respect to their activities. Essential components of pests management and pesticides management are described briefly.
Pesticides management has become very important and they should only be applied when either cultural or biological control means may not be effective or pests population have reached to a high level. Other components like presentation, cooperative efforts, rotation of crops, timing of sowing have been mentioned which all form the overall control scenario. Changing pests scenario with respect to environment, pesticides have been discussed.
To make out necessity for biological control, some of the harmful effects, so far noticed have been compiled including build up of BHC, DDT residue. The report of various agencies have been included to emphasize the need for biological control. The chapter also contains average dietary intake of DDT and BHC residues in various countries (expressed as mg/person/day).
Biopesticides are the use of biocontrol agents, normally the chemicals which have been produced by plants or organisms which feed on the pests or use them as a substrate to grow and nourish on them. The biochemicals act as toxic agent to pests check the growth of pests and in process themselves get degraded and in due course of leave not much harmful effect on plants or human beings or environment. Various types of organisms which act as pesticide have been classified into parasitoids, predators, pathogens. They help in maintaining another organisms’ population at lower density than would occur in their absence.
Chemicals produced by biological activities like terpines and sterols can be extracted from marine flora and have been found to be toxic. Some of the organisms can be used as pesticides. Thus, a vast array of chemicals or natural resources are available for regulated control of pests management and economic forest management. Switching over to biologically produced chemicals will be ecofriendly as well as conserve the non available petroleum and energy resources.
In India, the neem plant has been in use from the first century BC for medicinal purposes and control of certain diseases. Since then, it had been used in various ways to protect greenery. It has been found that chemicals extracted out of their seeds and seed kernels are effective bio-pesticides. This has been verified by various field trials and India has got a potential of about 6.0 million tonne of neem seeds per year and potential to produce upto one lakh tonne of neem oi. The neem products are competitive in prices and quality. As a result of the extensive research all over the world, neem based products have been formulated and are in the market. To name a few, Margosn O and Bioneem developed by W.R. Grace International Co., Philadelphia, USA, and Azation and Turplex developed by Agri Dyne Technologies, Salt Lake City, USA, are being marketed after registering with Environmental Protection Agency, USA. Neem Azal developed by Trifolio M GmbH, Lahnau, W. Germany also is in the market. In contrast, there are more than two and a half dozen products developed in India and of them about a dozen are in the market after registering with Central Insecticide Board, Faridabad.
In addition to the toxic chemical available from neem, there are a thousand plant species found to possess insecticidal properties. Some of them, like Pyrethrum obtained from Chrysanthemum Cinerarifoliumt flower, nicotine sulphate from waste tobacco materials, rotenone obtained from extraction of ground roots of derris and alium oil fraction of garlic and bitter gourd seeds have been in use prior to developing synthetic pesticides and were effective. Their use has now been re-established by field trials and effectiveness has been checked against various pests and the various pesticides out of them have been developed in patented for use needs to be promoted. This source for toxic chemicals which is biodegradable is getting wasted because they are somewhat slower in action and secondly large scale manufacturing and supply distribution is not possible for them. Therefore, higher advertising cost and low profitability discourage their utilisation. Some of the important sources of toxic chemicals from higher plant groups have been listed in a chapter.
Field trials have been extensively carried out on use of biopesticides and some of the uses are described crop-wise and pest-wise. It is interesting to note that cotton as a crop forms hardly 5% of the total agriculture production, but it consumes about 50% of our total pesticides production. Field trials have clearly shown that bollworms which are the major group of pests in cotton can be effectively controlled by Trichogramma. The parasitoid Chelonus blackburni, introduced from other countries, attacks all the three species of bollworms. It was mass-multiplied and tested in the cotton-growing tracks of Karnataka, Tamil Nadu, Maharashtra, Gujarat, Haryana and Punjab. The green lace wing Chrysopa scelestes is an effective predator against cotton aphids, American bollworms, thrips and mites. The mass production technique of this predator to cover a wider area has been standardised in India. The sugarcane internode borer is an important pest as sugarcane in south India. the luxurious dense vegetative growth prevents insecticieal application.
Inundative rlease of Trichogramma at weekly intervals has been found to give adequate control on the pest. Its utility and cost-effectiveness have been demonstrated in large-scale field experiments in the field areas in Tamil Nadu. The release of this parasitoid was very effective against sugarcane top borer in north Bihar. The release of Epiricrania melanoleuca parasitoid in Uttar Pradesh, Bihar, Punjab and Sriganganagar and Bimdi districts of Rajasthan resulted in a saving of Rs.4 crore by controlling sugarcane plant hopper. The parasitoid was released at 4,000-5,000 cocoons and four to five lakh eggs/ha. The fungus Metarhizium sp. was found to eliminate plant-hopper totally is less than half the cost of 10 to 14 sprays of pesticides.
Similarly, the pest of oil seeds have been controlled by Telenomus predator, Ninon and Microplitis machlipennis szepl. Field trials have also conducted on pests of oil seeds where parasitoids like Elasmus nephantidis, Brachymeria nephantidis, Xanthopimpla sp. are used in control of leaf caterpillar in Kerala.
In the rice ecosystem, an important biological control approach is conservation of the existing natural enemy complex. At least nine parasite species have been reported to attack rice stem-borers besides some predators. Lycosid spiders are potential predators of brown plant-hoppers.
Ther mirid predator, Cyrtorphinus lividipennis, is an other effective predatory bug feeding on brown plant hopper. The rearing technique has been standardised in laboratory host insects and release at 100 mirid bugs or 50-75 eggs/m2 at 10 days interval are very effective.
A chapter also covers the use of biopesticides against crops vegetable pest, tamarind pests in vegetables predatory mites, Amblyseius tetranychivorus and Phytoseilus parasimilis have been identified to kill effectively the phytoiphagous mite species on vegetables such as brinjal and bhindi.
The cutworm complex was found attacked by entormopathogenic nematode Neoapleccollaris. The white grubs in potato were found infectoids, Chelonus baclburni, C. Kellieae.
Cultural practices-destruction of alternate hosts (Impomoea spp.), removal and burning of plant residues after harvest, deep ploughing of field after harvest, earthing-up, crop rotation and use of short-duration varieties help reduce the weevil infestation. Such practices can control many other pest-attacks and are in line with healthy agricultural practice.
One of the foremost requisites for biological control programmes is the availability of adequate information on the presence or absence of natural enemies pests etc. in a particular area where control is needed. Production of suitable parasitoid in local insecory under initial guidance by scientific plant protection laboratories is essential.
A brief collection of information on global scenario, it is generally accepted that about 1000 tonne of bio-insecticides are produced in the USA and it is estimated that about 2000 to 3000 tonne is the world wide production. Some of the bioinsectidices have been tested and registered in various countries. Most common is the B.T. which is found effective against 90 different insects.
Eighty per cent present tonnage of B.T. is used to control the insects of lettuce and cole crops, particularly cabbage looper (Trichoplusia sp), tobacco bud worm (Heliothis virescens), Tobacco horn (Manduca sexta) and several other forest pests.
In Thailand, control of rice pests assumed critical importance as largest brown plant hopper intercepted their extensive rice production and chemical pesticides showed failure year after year. Brown plant hopper was keep under complete biological control and on pest resistant varieties.
Indonesian experience that insecticides induce explosion of pest population but integrated pests management has increased rice production by 12%. Whereas this reduced pesticides used on cotton by about 50%. They relied on trichogramma in cotton pests. This reduction of pesticides use has not cost any significant decline in cotton fields. Although real economics is not available, using Trichogramma has been twenty times cheaper than chemical pesticide usage in the USA.
In Andhra Pradesh, four commercial laboratories are mass-multiplying an egg parasitoid Telenomus prolitor to control castor semilooper. Trichogramma sp. parasitises 50 to 95 per cent of eggs of this pest in Gujarat. Microplitis maculipennis parasitises the larvae to the extent of 70 to 90 per cent. For mustard crop, severely attacked by aphids, there are effective natural enemies, parasitoid, Diaeretiella rapae and coccinellied beetles.
Pod borers are serious pests of pulses of which gram pod borer, Heliothis armigera, is prominent. The parasitoids, Trichogramma and Campoletis spp. were attempted for field release. Other possible natural enemies are Barcon hebetor and Telenomus sp. the NPV is the most effective insect pathogen of this pest and this is being mass-multiplied in various centres for large-scale field use.
In control of apple pests, the chalcid parasitoid aphelinus mali which was first introduced in the Kullu valley and later in Kodaikanal and Coonoor of the Nilgiris, has played an important role. A natural parasitisation of 70-80 of wooly aphid of apple is recorded after decades of field release, indicating the establishment of the natural enemy. In the control of San Jose scale of apple and other fruit trees two important parasitoids, Encarsia perniciosi and Aphytis sp. are more promising. The former species has established itself in many apple growing tracts. For the control of another serious apple pest, codling moth, two exotic species of Trichogramma were found effective in Ladakh.
The fungus, Metarhizium sp. was found to cause 100% destruction of sugracane plant-hopper Pyrilla perpusilla in North India. Detailed studies on culturing and dosage habve been made and the method of mass production of N. anisopliae, the green muscardine fungus, has been developed for use against coconut rhinoceros beetle in Tamil Nadu. It attacks all the stages of the pest under manure pit where it lives causing 100 per cent destruction of larvae.
A few species of fusarium were reported to cause 90% destruction of Coccus viridis, the coffee green bug, within 10 days after application. They also infect various pests like brinjal mealy bug and spotted beetle and aphids on crucifers. This fungus was found to be safe to all instars of mulberry silkworm, honey bees and certain natural enemies of insects.
Biopesticides can be economically produced. However, large scale field trials have only to be carried out in USA. One of the bioinsecticides shifted its host base. Another useful product and such dangerous status has to be protected and therefore the production and use of the predators and parasitoids has to be done under the supervision of the research associates, who can keep watch on future development of the predators. The technologies essentially developed in laboratory and field trials are now well established and ready for transformation to manufacturing units. Although, in some of the cases, their product shelf life is limited.
Biopestisides need to be produced by small insectories, catering to the need of a small area in each village by educated farmers can be trained by research institutes and later on the technologies can be transferred to village level. This will benefit the farmers and keep the cost under control. In some cases in South India and in Punjab, the cotton wool worm etc. are successfully controlled by Trichogramma. These predators are produced on small scale only. This method is workable in the present circumstances till long time stable products are available for production in large units.
Similarly botanicals or products of higher plant group are also fast biodegradable but the disadvantage is the products are unstable for long periods. Although, W.R. Grace has developed the technology thereby neem extract can be long time stable. Equivalent good technologies have been standardised and are available from National Chemical Laboratory. The other higher plant products were very much in use some forty decades ago and were out dated by synthetic chemicals and it can be brought back as heir trails have been given the successful results. The technologies are well known, adoption on small scales is easily possible, does not require too much complicated equipments or instruments. Number of plants and their toxicity amount or resources required or effectiveness to the particular preys, all such data is available in detail. Some of the products are already in market and are utilised by the knowledgeable farmers. Many technologies are available from Tamil Nadu Agriculture University.
An overview brings out clearly the significant role, the botanical and biopesticides can play in future, particularly under the umbrella of Integrated Pest Management. There is no doubt that most of the potential species of higher plants have not received the due attention of active researchers for pest control and allied purposes. Presently, the only plant of promise for field use is neem (Azadirachta indica A. Juss) which has been already researched for over three decades and extensively deliberated by the international scientists at four major international neem conferences, besides the other national and international forums. Even in this case, the large scale field trials are scarce and the toxicological information till wanting. There are also apprehensions about the product stability as well as about the availability of the raw materials in requisite amounts in the immediate future.
Several mechanical traps are known which could be used to monitor the pest activity and its build up. The idea of biological control measures, conservation of natural parasites and predators in the ecosystem and inundative release of egg parasite be explained to farmers. The farmers should be taught to use relatively safe agrochemicals in the right doses alternatively. The plant resistance is a very cheap method of pest control. Multiple resistant varieties to be evolved for the farmers. Regular monitoring of pest activities at village, block, district, state and national level be done by various agencies involved in agriculture.
In conclusion, it can be said that with the changing cropping pattern, there has been major shift in insect, pest and diseases. This problem is to be controlled by integrated pest management technique. Farmers have to take key position in implementing the technique through appropriate timely and precise adoption of package of practices. Skill oriented farmers education, therefore, becomes more relevant and has to be encouraged to make agriculture sustainable.
The report has been concluded with recommendation and action plan for implementation of environment friendly pest control measures, need of educating farmer by training and retraining and making available comic books on subject, video presentation and broadcasting of programmes over TV and Radio Receiver’s and by creating a team of trainers under the guidance of research and plant protection laboratories, with equal interest by local authorities in promoting such efforts. Proposals have also been made for R&D laboratories for significant further economics of biocontrol and promotion and field demonstration to farmers. They are also recommended to create training materials like video cassettes for display on TV and Village demonstrations even audio cassettes on biocontrol of pests could be useful alongwith other publicity / information material.
Updating R&D labs, integration between R&D lab and field scientists working as various crops. Training needs for scientists and demonstrators have been identified and can play major role if implemented in proper direction keeping overhead/infrastructure costs limited.
An attempt has been made to quantify cost of planned programmes and benefits accrued from such efforts immediately and also in the long term. The funds investments although small would enable to have eco-friendly pesticides with easily available locally produced materials.
Lastly, report concludes with assessment of impact of such efforts; will also eliminate expenditure on health care and hazardous chemical management as well as reduce accidents like Bhopal gas tragedy etc.