The Tribune, Chandigarh, India - Agriculture Tribune

Nefarious pest of rapeseed-mustard
Ajai Srivastava

Rapeseed-mustard is one of the important oleferous crops and constitutes the major source of edible oil for human consumption and cake for animals. Every effort is being made to increase the productivity of this crop by adopting improved package of practices such as use of high-yielding varieties, optimum use of fertilisers, irrigation and plant protection measures in order to meet the growing demand of oils.

Thirtyeight insect-pests are known to be associated with different stages of the rapeseed-mustard crop in India. The mustard aphid, Lipaphis erysimi (Kalt.), is the key past in the rapeseed-mustard growing areas. Yield losses due to this pest vary with the variety, agro-technological practices and the environmental factors. However, it is known to cause yield losses up to 42 per cent under different agro-ecological conditions. The damage is caused by nymphs and adults which are louse-like, pale, greenish insects. They are seen feeding in large numbers, often covering the entire surface of flower buds, shoots, pods etc. This insect is most abundant from December to March when it infests various cruciferous oilseeds and vegetables. During summer, it is believed to emigrate to the hills and there is some evidence that aphids also survive on abandoned stray plants of cabbage and on cruciferous weeds in the plains. The pest breed parthenogenetically and the females give birth to 26 to 133 nymphs. They grow very fast and are full-fed in seven to 10 days. About 45 generations are completed in a year. Cloudy and cold weather (20° C or below) is very favourable for the multiplication of this pest. Both the nymphs and adults suck cell-sap from leaves, stems, inflorescence or the developing pods. Due to very high population of the pest, the vitality of plant is greatly reduced. The leaves acquire early appearance, the flowers fail to form pods and the developing pods do not produce healthy seeds. The yield of an infested crop is reduced to one-fourth or one-fifth.

Prevention:

— Raya varieties Varuna, RCC4, T-6342, RC-199 and RH-7846 were found tolerant to the mustard aphid attack as against brown sarson variety BSH-1, Gobhi sarson variety HPN-1 and yellow sarson variety YST-841.

— The lines/genotypes possessing phenotypic characters like apetalous white flower, glossy stem and leaves and purple leaf colour in B. Juncea (L) provided initial resistance to mustard aphid, but turned into susceptibility under severe aphid pressure at the later stage of crop growth.

— Early sowing fist fortnight escaped aphid infestation without any appreciable yield loss as compared to the late-sown crop.

— Sowing in rows 30 cm or 45 cm apart with a plant space of 10 to 15 cm is found to minimise the incidence of pest.

— Removal of aphid infested twigs from the fields in the first week of January can save the cost of one to two insecticidal sprays.

— The economic threshold level of mustard aphid incidence worked out to be nine to 10 aphids on central twig/plant on 10 per cent of the plants. Hence it is recommended that the crop be sprayed with exydemeton methyl (0.025 per cent) or dimethoata (0.03 per cent) or phosphamidon (0.025 per cent) in afternoon to avoid mortality of pollinators and predators.

— The appearance of predators coccinella septempunctata linnaeus and parasite and diaeretiella rapae (curtis) during February resulted in sharp decline of the mustard aphid.

— Rains of light intensity in January and up to mid-February resulted in the population build-up of mustard aphid while the rains in the last week of February or March had adverse effect on the population of pest.

Feasible alternative to synthetic pesticides
K.K. Gill, B.S. Gill and S.K. Dhillon

Insect-pests cause considerable damage to agricultural crops. A number of chemical insecticides have been developed and are being effectively used to control noxious insect populations. The continuous use of these synthetic insecticides causes increasing problems for human health and to the environment. Now, it is widely realised that insecticides thus developed exert immediate side-effects and sometimes long-term indirect effects on living organisms and environment. Potential insecticide e.g. DDT that once proved effective in controlling many species of pests was found to persist in the environment for 15 to 20 years and accumulate at an alarming concentration through food chains. As a consequence in North America, many species of birds were severely depopulated. Further, many of the targeted insects have become resistant to a majority of insecticides. As a result, more number of sprays with higher concentrations had to be applied to control the insect-pests of different crops. In addition, due to non-selectivity beneficial species are also killed.

In view of above abuses of insecticide use, alternative means of controlling harmful insects have been felt. Naturally produced insecticides by plants or micro-organisms could prove effective substitutes which are feasible and economical also. In addition, these compounds are highly specific for a target insect species, biodegradable and slow to select for resistance. Mention can be made of bacterium Baccillus thuringiensis (Bt). At present, 90 per cent of bioinsecticides used, take the advantage of the insecticidal properties of Bt. This bacterium comprises a number of strains, each of which produces different toxin that can kill certain specific insects. For instance one of the strains being toxic to American bollworm and another control mosquitoes and black flies.

Bt’s mode of action: Unlike most of synthetic chemical insecticides, Bt toxins are not contact poisons, they must be eaten to be toxic. These are consumed by the insects while feeding on the leaves. Toxin binds itself to the receptors present in insect’s mid gut, thereby leading to paralysis followed by death of the insect. This happens only in an alkaline medium. So we, with our acidic guts, do not need to worry. Bt toxins can be used for protecting crop plants by two ways — insecticidal sprays and transgenic (Bt) plants.

Insecticidal sprays: The Bt has been used to produce biological insecticides for foliar application for over 50 years. These products were, and are still, produced by fermentation of single Bt strains in crude, inexpensive media. The most common formulations include wettable powders, or dispersible granules but oil and aqueous-flowable preparations have also been produced. Despite numerous merits of biological insecticides, their use is still limited due to their low field remanence. Indeed, the toxins are rapidly degraded by solar UV conferring short-term protection and requiring frequent sprayings. However, these inherent disadvantages can be overcome by developing plants with inbuilt Bt gene (Transgenic plants).

Transgenic (Bt) plants: To make plants resistant to insects, take the Bt gene and put it in the plant. Plants expressing these toxic genes (which could as such be considered "plant pesticides" have several advantages over classical chemical means in plant protection. Borers, for example, are difficult to reach by conventional means once they have penetrated plant tissues. Since, toxin expression can be achieved throughout the whole plant during the entire lifecycle, the deployment of transgenic plants would allow the control of major insect-pests. Furthermore, pests are exposed to the toxins at their most sensitive stages (early larval instars) and conversely, plants can be protected when they are most sensitive to insect attack. Such transgenic plants have proved more effective to control insects that have developed resistance to chemical insecticides such as American bollworm, the most destructive pest of cotton. The active compound is maintained in the plant tissues and has the potential of lowering cost of sprays. Finally, due to their selectivity and other advantages, transgenic plants expressing Bt toxin genes can easily be integrated in an integrated pest management (IPM) scheme.

The Bt gene has been transferred to impart resistance in several major crops like cotton, maize, rice, potato, tomato, tobacco, etc. Bt cotton and Bt corn have been commercialised in the USA, Canada and Australia. Bt cotton in the USA resulted in insecticide savings as high as $ 60 to $ 120 per acre. In the USA, more than 10 million acres of transgenic-insect resistant crops, including cotton, corn and potatoes, were planted in 1999 and are on the verge of extensive plantings. however, at present, insect-resistant transgenic crops have not been released in India. It is now a established fact that Bt crops are environmental friendly, non-toxic for mammals and effective in controlling the specific insect-pests unlike hazardous synthtic pesticides. In view of this discussion, it is, therefore, imperative to test their efficiency against pest which are otherwise difficult to control. Resently, the Indian Government has given "biosafety clearance" to the controversial genetically engineered cotton developed by multinational Monsanto for large-scale cultivation and marketing. Bt cotton would help farmers save money they currently spend on chemical pesticides.

‘Follow sanitary practices for safer milk’
Manoj Kumar

After the Green Revolution, Punjab has successfully moved towards White Revolution by producing the highest per capita milk in the country, but the dairy experts of the Punjab Agricultural University (PAU), Ludhiana, have warned the policy makers and the milk producers that unless sanitary practices and judicious use of pesticides are followed by milk producers and farmers, the future of this sector is highly questionable.

They have cautioned that it is not the animal rights activists like Ms Maneka Gandhi, but the presence of aflatoxins, particles of the DDT, the HCH and other harmful insecticides above permissible limits found in the milk produced in the state which would affect the demand for milk and milk products in the domestic and international markets. In fact, recent studies conducted by the Department of Veterinary Microbiology and Veterinary Public Health have found that more than 50 per cent of the samples of milk taken from Ludhiana and its surrounding areas were contaminated due to the presence of these particles. They have recommended simple sanitary practices and judicious use of pesticides to enhance the quality of milk.

A study conducted by the Department of Veterinary Microbiology has found that most of the milk produced in the region is contaminated by highly toxic aflatoxins — produced by the fungus present in low quality animal feed — which can cause liver damage, cancer and suppression of the immune system. The study has observed that aflatoxin is indeed found in milk and milk products even in the developed countries like the USA, Germany, the Netherlands and the UK, but in much lower quantity. It has revealed that out of 125 samples of milk and milk products taken from rural and urban areas, more than 50 per cent samples had up to 500 ppt per litre aflatoxin as compared to 10 ppt per litre found in Switzerland.

The experts warn that aflatoxin is only partially affected by pasteurisation, sterilisation or processing into cheese, butter, burfi, khoa or paneer. They said that indiscriminatory use of anti-biotic by the farmers over the years has also resulted into passing of their residues to the animal milk. The contaminated feed, especially the readymade one, prepared by some dubious companies in the region, has badly affected the quality of milk. The problem is aggravated in the rainy season, from July to September, due to high humidity in the weather, they say.

Another recent study conducted by Dr JPS Gill, Department of Veterinary Public Health, PAU, has also observed that though DDT has been banned in the state, its particles are still found in the animal milk, much more than the safer limits recommended by the World Health Organisation (WHO). Elaborating the process of contamination, Dr Gill, says,‘‘ The overuse of the DDT to check malaria till recently, and now indiscriminate use of pesticides like the HCH and other organochlorine over different crops especially cotton result in accumulation of their residues in the final produce. Later the fodder and oilcakes used for animal feed often result in accumulation of their residues in the animal fat and muscles, and are finally transferred to milk. The presence of these harmful particles has been found in more than 85 per cent of the samples.’’ He admits that these particles are also found in developed countries as well, but within safe limits. In the long run, the consumers can be afflicted by various diseases like breast cancer, decrease in immunity, etc.

Dr S.K. Jand, Professor of Bacteriology, Department of Veterinary Microbiology, PAU, has also done extensive work on the regulation of aflatoxins in dairy products. He says, ‘‘We should not be panicked over this matter since the situation could be easily controlled by following sanitary practices and judicious use of pesticides by the farmers. There is a need to create mass awareness among the farmers about its effects on consumer health, and export of milk and milk products.’’ Incidentally, the Milkfed has already started a pilot project to promote sanitary practices among commercial dairy farmers in the state. It has started showing some positive results, claimed the officials at the Verka Milk Plant in Ludhiana.

Diversification: is it as simple as it sounds?
Khushwant Ahluwalia

Punjab has a new government installed. Excitement is writ large on the new incumbents’ faces and there is a lot of enthusiasm being portrayed to get Punjab prosper again. Diversification remains the keyword amongst the top policy makers in Punjab.

Somehow the articulation ignores one simple question? What does the government actually mean when it uses the term diversification? Does the word simply mean shifting from one crop to another or does the diction have substance attached to it? Is the process as simple as it is made to sounds? If not then what would be the measures taken to bring about a positive change in the once prosperous agriculture economy of Punjab?

Diversification would involve a very meticulous approach starting from the point of sincerity that enables a clear direction to the bureaucracy, the agriculture university, the departments concerned and the farmer. In my opinion at the first instance, it would be the renewal of the lost trust between the government and the farming community that would be imperative to the success of whole process of diversification.

The word diversification as it is known to all and sundry can be heard and read in every seminar or newspaper. It is in every economist’s armor but yet the paradigm. But yet there is no concrete step that can be termed as a step towards diversification. Rather there are challenges.

— Have we identified which areas in agriculture we want to diversify in. If yes, then which part of Punjab needs to start diversifying at the earliest, for everybody does not need to change? We need to change one-third of the cropping pattern.

— Is it oilseeds, agro forestry, dairy farming, aquaculture or horticulture that we have identified?

— If it is horticulture then is it vegetables or fruits?

— If fruits then what kind of a long-term strategy are we looking at in terms of infrastructure, post-harvest management and, most importantly, marketing of the produce.

— What kind of a timeframe are we looking at when we would be able to say that Punjab’s agri-economy is cosmopolitan?

— Is the plan WTO friendly? When I use the term WTO friendly I mean the competitiveness of Punjab’s agriculture vis-a-vis international guidelines and secondly, it should be within the legal framework as laid down by the WTO secretariat.

— Are we ready to initiate land reforms to make agriculture a viable enterprise?

— With small land holdings and very low incomes, will our farmers dare to diversify?

— In the absence of a strong economic package and a marketing back-up, do we think farmers would be in a shape to diversify? No wonder we want to use the easy way out by paying the farmer to keep his land barren. But still if the suggestion seems to be the best plausible answer then what is the hitch of implementing it. Go ahead and implement it.

One has serious doubts whether we have a strategy in place to counter this bundle of questions that accumulate everyday. Attention is drawn not only to the serious crisis in the political will to respond to the momentous problem of surplus foodgrains but to the different stances taken by different political parties when in opposition or in power, respectively. During the last procurement season for paddy, the Congress, which is the ruling party now, was quite convinced that the Akalis would not be able to get the farmers’ paddy procured, thus, resulting in a great political advantage. Today, the Akalis have pinned their hopes on inadequate procurement of wheat. With such political stances can we hope of a long-term solution? Is the political jugglery limited to foodgrain procurement and not beyond? In the end the only suggestion that comes to my mind is that we need to derive one simple conclusion from the crisis "where there is political will there is a way."

Farm operations for April

Ornamentals

Annuals

The borders and beds intended to be used for summer flowering annuals should be cleaned and prepared for the purpose. As soon as the summer flower seedlings e.g. cosmos, gaillaridia, comphetrena, cochia, zinnia, etc. are ready, they may be transplanted in the above noted well prepared beds. Transplanting work may preferably be carried out in the evening followed by water.

Seed should be collected from the already selected winter flowering annuals. After proper drying and cleaning, the same may be stored for the next season.

Permanent plants

Pruning and training of permanent trees, shrubs and creepers, if found, may be carried out wherever required, liberal quantity of manure may be spread around the plants and mixed well in the soil. Keep irrigating these plants regularly. Do not allow the weeds to grow around them.

Cannas will be at their best and should now be selected for propagation purpose. If the cuttings of shrubs are not sown so far, the same be sown early this month.

Chrysanthemum

In the case of large-flowered chrysanthemum, encourage the growth in beds by regular watering. In pots, limit the watering to check the growth. In the case of small-flowered chrysanthemum. branching may be encouraged by pinching back to 10 cm from the ground.

Roses

Major flowering of the rose will be over in this month. Keep removing the faded flowers and suckers from the root stock. Timely watering, weeding and hoeing will keep the plants in good conditions.

Lawns

For having lush green lawns, their timely watering and frequent mowing is very important. Irrigation of lawns through sprinklers is the best for getting excellent results. If the growth of the grass is poor, a light dose of nitrogenous fertiliser may be given.

Pot plants

Foliage plants in pots will have resumed activity. The delicate ones should be moved away from the positions exposed to the direct sun.

Bulbous plants

The bulbs of "nargis" and "gladiolie" which have become dormant and their leaves are dried up, the same may be taken out from the soil, cleaned, treated with some fungicide, dry them and then store in some cool dry place. The bulbs of calediums and "football lilly" may be planted, if not planted last month.

Horticultural operations

It is the month marked with a lot of change in weather. The temperature rises rapidly and humidity gets low. The growers are advised to adopt the measures to save their valuable fruit trees from drought, windstorm and sun injury. Whitewash the trunk, provide shelter to young trees and give frequent irrigation.

The heavy bearing cultivars of peaches like Shan-e-Punjab and of plum like Kala Amritsari and Sutlej Purple normally need thinning in early days of the month to minimise the danger of limbbreakage and to improve the marketable size and quality of the fruits.

Apply second dose of inorganic fertilisers to the fruit trees of citrus, pear litchi, plum, grapes etc.

The stock sprouts emerging from the newly planted fruits below the bud union should be removed/pinched off regularly.

In young orchards sathi moong can be sown in the last week of April.

To check pathological fruit drop in citrus give one spray of 2: 2:250 Bordeaux mixture during the month.

To check zinc deficiency in citrus, spray the affected trees with 0.3% zinc sulphate solution, without addition of lime, to spring flush in April.

In order to get only winter seasons guava crop, spray urea 10% during April-May when maximum flowers have opened. also withhold irrigation during this period.

Spray 625 ml of Nuvacron 36 SL (monocrotophos) or 670 ml of Rogor 30 EC (dimethoate) in 500 litres of water on citrus crop to control citrus psylla.

To check insect-pests and diseases in grapes, spray 500 ml Nuvacron, Bavistan 400 litres of water for controlling anthracnose and belytan 40 g in 100 litres of water for the control of powdery mildew and Bavistin @ 400 g/400 litres of water for controlling anthracnose.

In ber, spray 250 ml of Rogor or 100 ml dimecron in 250 litres of water for the control of lac insect.

To check peach leaf curl causing aphids early in the month. Spray 500 ml rogor in 500 litres of water.

Fodders

— For early kharif fodders, sowing of bajra, maize, cowpea, etc may be carried out after harvesting of rabi crops. Cowpea is a very quick growing leguminous fodder which can be sown in mixture with maize or bajra.

— Berseem crop for seed production should be frequently irrigated. Kashni and other weeds should be rogued out of the crop meant for seed production.

— Gram catterpillar attacks the berseem crop for seed. Spray 500 ml of Thiodon 35 EC in 100 litres of water/acre at the irrigation of flowers. Repeat after 10 days, if necessary.

— Stop irrigation to lucerne after full blossoming to arrest further vegetative growth for better seed production.

— Cultivate perennial fodder on some area. For this purpose, guinea grass and napier bajra can be sown in April.

Progressive Farming, PAU