«: AGROCHEMICALS: FATE IN FOOD AND THE ENVIRONMENT PROCEEDINGS OF A SYMPOSIUM, ROME, 7 - 1 1 JUNE 1982 JOINTLY ORGANIZED BY IAEA AND FAO l^J I N T E R ...»
As will be seen later in this section, even this capacity is not being fully utilized. It is also clear from Table III that in Indian agriculture maximum use is being made o f insecticides, followed by fungicides. As yet, not much herbicide has been used and although the installed capacity is 3250 t only about 4 0 0 t are being produced. The low consumption o f herbicides in India is distressing, since reduction of crop yields through deprivation o f nutrients by herbivores is thought to be much more than the loss caused by other pests. Weeds deprive the crops o f 30 to 40% o f the fertilizer, which is the costliest input in Indian agriculture, and the position is becoming more serious as the amount of fertilizer being used rises. Low use o f herbicides may be due to many causes, such as availability o f cheap labour, high cost o f herbicides especially the newer types, the belief that more use o f herbicides would add to the unemployment problem and consequent lack o f promotional activity, and lack o f extension activity to promote the sophisticated technology needed for herbicide application. At present, the largest users are the tea, c o f f e e and rubber plantations, which are more organized and where the cost:benefit ratio is higher.
The consumption pattern and trend o f increase or decrease are shown in Table IV . Even though there was a rise o f about 22% in the overall consumption o f pesticides, the percentage-wise use o f various groups o f pesticides has not changed very much. Only weedicides and fumigants have shown an appreciable increase in recent years.
The pesticide industry in India n o w produces 57 basic chemicals . O f these, 28 are insecticides, although only four are major ones, i.e. BHC, DDT, carbaryl and malathion. O f the four, only three are important for agriculture. DDT is used mainly for malaria control by government agencies. The largest single chemical used in agriculture is BHC, which contains 13% active isomer. It is also used for public health purposes and in locust control and constitutes about 60% o f the total pesticide produced in the country.
The production volume o f carbaryl and malathion is second to BHC. Although the installed capacity for carbaryl is about 5000 t, actual production is only about 3000 t. The capacity for malathion production has recently been increased greatly as it has been selected as an alternate chemical for public health uses. The manufacture o f endosulphan has recently been increased and it is expected to be the most important insecticide for agricultural uses. The remaining insecticides consist o f a large number o f small volume OP compounds. Besides carbaryl, the only other insecticidal carbamate produced is aldicarb or Temik.
IAEA-SM-263/35 About 12 important fungicides are now being made, but again older types, based on sulphur and copper, predominate. The newer systemic ones are used only in small volumes and are mostly imported.
Although several herbicides are n o w being used in Indian agriculture only two, 2,4-D and paraquat, deserve mention and adequate amounts are being manufactured. Propanil and nitrofen have recently been added to this list. Others, used in small volumes, are being imported.
In the recent past preservation o f stored grains posed some problems and there was a need to produce more fumigants. Three o f these, aluminium phosphide, EDB and methylbromide, are now being produced in adequate quantities, especially for use in the government storage programme.
Plant growth regulators are being made only in small quantities, but their use is increasing.
In India, the pesticides in use are mainly o f the older type. These have many defects and have been abandoned elsewhere; their continuance in India is mostly because o f cost considerations. Small quantities o f organomercurials are still being used, mainly for seed treatment.
Further, it should be pointed out that it is planned to increase the production and consumption o f DDT in India. It is the cheapest chemical available for public health purposes and its consumption has remained steady for the past decade;
part o f it is produced and an almost equal amount is imported. Production o f this chemical is about to be doubled.
Pesticides, produced or imported and formulated, are not used evenly throughout the country. The maximum amount is consumed in southern India which, being warmer, is more prone to pest attack; the eastern zone, comprising Assam, West Bengal, Bihar and Orissa, is next in line, followed by the western zone.
The lowest pesticide consumption is in the northern part, which has a relatively colder climate.
Andhra Pradesh heads the list in pesticide consumption presumably because o f the requirements o f cash crops like cotton and tobacco and cereals like rice which are grown there.
Crop-wise consumption o f pesticides in India is shown in Table V .
Among crops, cotton uses the largest amount o f pesticide as it is susceptible to a large variety o f insect pests. Use o f synthetic pyrethroids (imported) has just begun and is showing spectacular yield increases. Among cereals, rice is the largest consumer o f pesticides. It is pertinent to note that not much pesticide has been used on maize which has a very high photosynthetic efficiency, soy beans which are the best source o f vegetable proteins, and groundnuts which are the most important source o f edible oil and hence these crops have not kept pace with production.
A comparison between the amount o f pesticide used in agriculture and for public health purposes is shown in Table VI [13, 14]; production figures are also 10 MUKERJEE
1960 10.6 5.5 153 6.5
given. Public health consumption has approximately doubled in one decade, but in agriculture there has been a manifold increase and it is rising steadily. Part o f this increase is certainly due to the increase in area under plant protection, but the real increase is due to intensification o f pesticide use, which has risen from 77 g/ha in 1965 to a current 450 g/ha.
Although pesticide consumption is rising very steadily in India, it is only a fraction o f the total estimated demand. Calculating the pesticide demand and forecasting consumption is a very difficult task and is often inaccurate owing to the uncertainties o f the monsoon. For example, as seen in Table VI [13, 14], after a steady rise in consumption during the g o o d monsoon periods o f 1977 and 1978, there was a steep fall in 1979, the year in which India suffered the worst drought o f this century. The pesticide demands envisaged by the Planning Commission by the end o f the sixth planning period in 1985 are 81 000 t. Total production figures for pesticides are much lower than the installed capacity o f 78 000 t and for the last three years they have remained stagnant, i.e. around 50 000 t. This, in spite o f the fact that the area under plant protection is being increased, albeit slowly. Several causes can be ascribed to this stagnancy, the main one being the steep increase in the price o f pesticides without a proportionate rise in production, resulting in a decrease in the cost: benefit radio, making this input uneconomic for farmers. Vagaries o f monsoon and drought could be other reasons.
The pesticide industry in India is a g o o d example o f 'mixed e c o n o m y ' as far as the manufacture o f basic chemicals is concerned. Although the industry was started by the multinationals, there are now participants from both the public and private sectors and at national as well as multinational level. The manufacture and use o f DDT is a government m o n o p o l y.
5. FORMULATION INDUSTRY
The pesticide formulation industry in India consists o f two categories:
large-scale units as a part o f basic manufactured goods and small-scale formulations that enjoy certain benefits from the government. The latter accounts for nearly 70% of the total production o f pesticide formulations (about 90 000 t). India uses mostly conventional types o f formulations, such as dust and water dispersable powders, and less emulsifiable concentrates and granular formulations. Modern formulations o f aerosols, ULVs and recent types, such as micro-encapsulated and flowable concentrates, are not as yet greatly used in India.
begun, unlike in developed countries where the polluting effects o f pesticides were discovered long after their initial use. The manufacture, sale and use o f pesticides are strictly controlled by the Central Insecticides Board o f the Ministry o f Agriculture. Any new pesticide or formulation must pass through very rigorous toxicological and environmental tests before it is allowed to be used.
India now has reasonably good R and D facilities to sustain the pesticide industry. The focus, however, is on application and development and not on the discovery o f new chemicals.
7. IMPACT ON CROP PRODUCTION
After years o f stagnancy and chronic f o o d shortages, the phenomenal growth in crop output in more recent years has been perhaps the most outstanding achievement o f Indian agriculture. This is the result o f embarking upon the path o f planned economic development. The absolute increase in f o o d grain production (76 million tonnes) in the past 30 years o f development ( 1 9 5 0 - 1 9 8 0 ) has itself far exceeded the absolute output (57.1 million tonnes) o f the initial triennium.
The increase in wheat output has indeed been most spectacular, being nearly four times that o f the average output in 1949—52. Besides wheat, there has been an all-round improvement in other crops like potatoes, cotton, sugar-cane, tea and coffee. Between 1960—61 and 1978—79 crop output recorded a compound rate o f growth o f 2.45%. In the period after 1 9 6 7 - 6 8 the growth o f production accelerated to 2.8% per annum . The major cause o f this overall growth has been mainly due to the increase in productivity and not to the increase in area under cultivation, which has probably reached a limit and can only be further increased with great difficulty. The increase in productivity is linked to the increase o f several modern inputs. Thus, the irrigation potential was raised from 22 million hectares in 1951—52 to more than 55 million hectares in 1980. While earlier Indian agriculture hardly used any chemical fertilizer, by 1980 the consumption o f NPK nutrients had reached 5.6 million tonnes.
In 1965—66 new high-yielding varieties o f wheat were introduced, ushering in what is known as the 'Green Revolution' and within 15 years the area under these varieties reached 45 million hectares. Production and distribution o f quality seeds have been organized practically from nothing. Agricultural chemicals also form part o f these essential inputs, especially for the high-yielding varieties.
As can be seen in Table VI, the area under plant protection has risen today to about 84 million hectares, which is 49% o f the total cultivated area.
It is difficult, however, to quantify the gains from the use o f pesticides alone.
After all, pesticides do not grow crops directly but help in protecting the gains from other inputs. The relation between total f o o d grain production and pesticide consumption is shown in Fig. 1 which clearly indicates the impact o f IAEA-SM-263/35
FIG.1(a). Total food grain production; (b) pesticide consumption.
pesticides on the total p r o d u c t i o n o f f o o d grains. T h e steep rise in f o o d grain p r o d u c t i o n between 1966 and 1975 also corresponds to a massive increase in the use o f pesticides.
A better c o n c e p t o f the impact o f pesticides may be seen in Fig. 2, which shows the increase in average productivity o f f o o d grains in conjunction with the rise in intensity o f application o f chemicals. Again, it can be seen that there is a close correspondence between the rise in productivity and the per hectare consumption o f pesticides.
Crop-wise analysis o f the impact o f agricultural chemicals o n yields reveals n o t o n l y the main areas o f gain but also where pesticides have not made m u c h impact.
7.1. Wheat: needed n o impact
The annual increase in wheat p r o d u c t i o n is shown in Fig. 3, which also depicts separately the rise in pesticide consumption. It will be seen that the wheat yield increased almost three-fold ( 1 0. 4 t o 36.5 million tonnes) within the short span o f 15 years. It is the main contributor t o the 'Green Revolution'. But it is doubtful whether pesticides have played any key role in this growth. As mentioned earlier, wheat does not suffer m u c h f r o m pest attack and losses have been c o m p u t e d to be only about 2.8%. Increased p r o d u c t i o n o f wheat, with the introduction o f highyielding varieties f r o m 1966 onwards, needed fertilizers and irrigation but not much plant protection.
However, if this level o f p r o d u c t i o n is to be maintained and further increased some plant protection measures will b e c o m e necessary in the near future.
Cultivation o f high-yielding varieties was first started in the Punjab, which in many ways had ideal conditions f o r wheat growing. Gradually cultivation was extended to the entire country and even non-traditional areas like West Bengal and Tamilnadu are n o w cultivating these varieties, as well as the neighbouring countries o f Pakistan and Bangladesh. It is n o w feared that if an epidemic o f rust or smut occurred it w o u l d spread like wild fire and p r o d u c t i o n o f this monoculture in the entire subcontinent would be threatened. The country lost about 1 million tonnes o f wheat last year due to loose smut intensification arising f r o m the free exchange o f seed materials and the susceptbility o f new high-yielding varieties. Smut control is possible with new systemic chemicals like vitavax and it is advisable t o start seed treatment with these chemicals as a short-term measure t o avoid this epidemic.
Gene d e p l o y m e n t in different zones would be the only effective barrier to avoid the threat o f rust, but it is a long-term process and needs constant attention.
Meanwhile, fear will continue since there are n o effective, economical chemical control measures.