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| AGRICULTURE TRIBUNE |
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Snow may
do an apple hat-trick Downy
mildew can down onion Organic
venture has success Tree talk Bird flu:
spread and control |
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Snow
may do an apple hat-trick
WIDESPREAD snow in the higher and mid-hill areas of Himachal Pradesh over the past week has raised the hope for a bumper apple crop for the third successive year. According to the data available at the fruit research station at Mashobra, near here, well over 1m of snow has been recorded in January, besides more than 75 mm of rain during the current winter (December and January). Weather gods have obliged the apple growers with snowfall just in time. A good spell of snow in January ensures a good crop as it lowers the temperature for a sufficiently long period to help meet the chilling requirements. Snow is considered as white manure in apple orchards. Over the past few years, erratic and inadequate snowfall has been affecting apple production. Normally a bumper crop is followed by a lean harvest — orchards in the state have been recording alternate bearing. The last season was exceptional. The state not only witnessed the rare phenomenon of two consecutive bumper crops but also recorded the highest-ever production of 4.50 lakh tonne. The year 2002 was also good with a total production of 3.58 lakh tonne. Delayed snow in February and a good monsoon ensured record production in what should have been a lean season. This year, the entire apple belt has received snow well in time, bringing cheer to the growers who are looking for a rare hat-trick of bumper crops. On an average, 1200-1500 hours of chilling (with temperature below 7`B0 C) are required for a good crop. This season the orchards have already had about 1000 hours of chilling and the recent widespread snow will extend the period beyond 1400 hours, says Dr S.P. Bhardwaj, scientist in charge of the fruit research station. More so, because there has been a shift in the pattern of snowfall over the past few years. Unlike the 1970s and even early 1980s, the region hardly gets any snow during December. In recent years, there has been snow only towards the end of January and in February, he observes. The quantum and
frequency of snow have both declined because of which the mid and
higher hills have seen shortage of water during summer. |
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Downy mildew can down onion
Caused by the fungus Pernospora destructor (Berk) Casp, downy mildew occurs worldwide wherever the crop is grown in cool and moist conditions. In India, the disease was first reported in Kashmir in 1974-75. Since then, it has been spreading slowly to areas around Rewari and Ambala in Haryana, and Ludhiana and Bathinda in Punjab. In Himachal Pradesh, the disease is particularly serious in Kangra, Mandi and Sirmour districts, causing 10-100 per cent losses in affected areas. Symptoms
In secondary or local infection, caused by wind-borne conidia, oval to cylindrical spots of paler than the normal green colour are formed on the leaves. Usually the older leaves are attacked first and the infection spreads to the sheath. If the leaf is infected in the middle part, it drops from the point of infection and the tip dries up. The entire plant is not killed, but the bulbs remain undersized. Downy mildew is more severe in seed stalks than the bulb crop. As the seed umbels become heavier, the weak stems break at the point of infection and prevent the maturation of seed. In the unbroken infected stalks, the seeds remain immature and shrivelled and are blown off at the time of winnowing. In nursery beds, the seedlings raised from infected seed carry systemic infection and under favourable conditions these are covered with sporangial growth of the fungus. In severely infected beds the seedlings topple over. The disease is introduced in new areas either through seed or infected bulbs. Oospores of the fungus develop late in the season. Downy mildew generally appears in the last week of February or in March. Intermittent spells of spring rain during February-April help create epiphytotics. Overnight dew on seed stalks aggravates the disease. The main sources of infection are the diseased bulbs used for propagating the crop and oospores present in diseased crop residue. When infected bulbs are planted the fungus grows with the foliage, produces conidia and these spread the disease to other plants. The fungus requires cool moist nights and only moderately warm days for quick development. Heavy dew or a saturated atmosphere is a better source of moisture than heavy rain, which washes away the conidia. The conidia of the fungus are produced in humid atmosphere at 4`B0 to 25`B0 C. They usually develop during night and mature early in the morning. The seed of the infected stalks carries the mycelium on to the next crop. The nursery raised from such seed develops systemic infection under favourable conditions. Downy growth of fungus on growing seedlings in nurseries has been noticed in Palampur and Dhaulakuan in Himachal Pradesh. Management Selection of seed and bulbs: Since seed and bulbs carry the infection, they should be got only from a healthy field. Crop rotation: Follow crop rotation with a four-year break in onion cultivation. Seed treatment: The seed should be treated with Ridomil MZ 72 WP @ 2.5g/kg seed before sowing in the nursery beds. Cultural control: Fields with weeds help in the development of disease, thus timely weeding plays significant role in the control of downy mildew. Apart from this, well-drained fields and field sanitation also help. Fungicidal sprays: The crop should be sprayed with Ridomil MZ 72 WP alone or alternatively with Dithane M-45 @ 2.5 g/litre. Spraying should be started 20-25 days after transplanting and repeated at 10-15 days interval. Three to four sprays are sufficient. A sticking and spreading agent, Triton X @ 1 ml/litre, should be used with the spraying material. — Dhanbir Singh, Akhilesh Singh and
H.L. Thakur |
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Organic
venture has success SOLAN: Economic gains, increased crop yield, and enhanced soil fertility are some of the factors which have motivated villagers near Parwanoo to use organic fertiliser, shunning chemical options altogether. An endeavour of the Integrated Watershed Development Project to introduce vermicompost, a 100 per cent organic fertiliser, made up of worm castings and decomposed organic matter, in the villages near its Parwanoo unit has had a taste of success. Farmers in Kyarad, Kalog, Rampur, Jugar, Chamog and Paproda villages were regular users of chemical fertilisers for growing tomatoes, capsicum, peas, ginger, maize and garlic. An average small farmer used five bags, which went up to 10 in the case of farmers with large land holdings. This incurred an annual expenditure ranging from Rs 2,000 to 5,000 for each farmer on fertilisers alone. Besides biological degradation of the soil, chemical fertilisers caused harm to humans as well as animals. Taking a cue from the HP Regional Research Centre at Dhaulakuan in Sirmaur district, the project officials initiated production of vermicompost at their Jabli range office. Sceptical villagers initially dismissed the idea and asserted that the worms shown to them were no different from the ones present in cow dung. It was only after a series of exposure visits of local villagers to the vermicompost production centres at the Great Himalayan National Park at Shamshi that an interest was generated in the new concept. A series of workshops and interactions with NGOs at different levels led to the selection of two villages under each unit of the project. Farmers of these villages were then persuaded to use only vermicompost and bio-products and no pesticides and chemicals to turn them into bio-villages. This brought discernible changes in farming practices. Most of the agricultural families adopted vermicompost and the benefits encouraged them to continue its use. When Santram of Kalog village grew garlic of increased size, the yield doubled in the same piece of land. Another farmer, Laxmi Dutt of Jajyar village, reduced the input of chemical fertilisers by 50 per cent and sold tomatoes worth Rs 15,000 from only 600 seedlings. Reducing the application of chemical fertilisers by as much as 50 per cent led to savings of Rs 80,000 per annum in these hamlets. Not only this, it resulted in higher yields and enhanced income. Also, the sale of extra vermicompost led to added revenue for the farmers. Being fast breeders, these red worms can consume food equal to their own weight in 24 hours. They reproduce quickly and eat all kinds of organic matter life fruits, vegetables and agriculture waste. Along with bacteria, they excrete juices that are full of nutrients and help in conditioning the soil. Preferring humid conditions, they can bear temperatures up to 40`B0 C and reproduce best at 25`B0-30`B0 C. The compost produced by these worms is packed with essential minerals for plant growth such as concentrated nitrates, phosphorus, magnesium, potassium and calcium. It also contains traces of elements like manganese, copper, zinc, cobalt, iron, carbon and nitrogen. Slow release nutrients that are water-soluble are immediately available to the plants. It gives soil excellent structure, porosity, aeration and water-retention capabilities and contains a high percentage of humus. It benefits the plant in making it
grow fast and stronger. Lacking chemicals, the crops from such fields
fetch better market value. Also, farm waste and weeds like lantana,
which are not even consumed by animals, are used in its production. |
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Tree
talk
The bark of kaiphal is 10-15 mm thick and brownish grey in colour. The leaves are 10-15 cm x 2-4 cm and lanceolate in shape. These are serrate in young plants but entire on mature ones. The texture being coreaceous, these are glabrous above and rusty pale below. New leaves sprout during April-May and old ones are shed gradually, though not completely, during autumn. The inflorescence appears during October-November. The flowers are in receme bunches, the female being above and male ones lower down on the common peduncle. Kaiphal fruit appears during March-April. The oval-shaped fruit is 10-12 mm long and 6-8 mm in diameter and is deep reddish when ripe. The pulp is also reddish brown and pleasantly sweetish sour in taste. The tree matures in 50-60 years, when it is 10-15 m high and 40-50 cm in diameter at breast height. Silviculture: Kaiphal is a strong light-demanding tree. Young plants, however, do better in shade. Sub-tropical hilly terrain experiencing temperatures between 5`BA and 45`BA C and rain/snowfall between 150 and 250 cm per annum is suitable for this tree. The species can come up on virtually all kinds of soil, but sandy loam on a calcareous base suits it best. Distribution: Kaiphal comes up naturally at altitudes between 1000 and 2000 m in mixed forests of deodar, kail, ban oak, rhododendron, etc. Its natural habitat spreads from the Ravi in the west to Khasi hills in Meghalaya and Sylhet hills in Bangladesh. In Himachal Pradesh, it is found growing well in Chamba, Mandi, Solan, Sirmour and Shimla districts. Utility: Kaiphal wood, purple grey in colour, weighing 25-28 kg to a cubic foot, is close grained and hard in texture. It is not very good as construction timber because it tends to split. It is, as such, used as cheap firewood and for fence posts. The fruit, when ripe, is sweetish sour and is eaten as a delicacy. The bark, 1-1.5 cm thick, is used with for a variety of pharmaceutical applications. It is exported from the hills to the plains and utilised in a variety of ayurvedic and Unani medicinal preparations. A brew made of dried kaiphal bark relieves asthma, diarrhoea, fever, lung infections, chronic bronchitis, dysentery, diuresis, etc. Raw bark when chewed relieves toothache and gum problems. It is also considered useful in complaints of cough, gonorrhoea, piles and bad throat. Some of the medicinal trade preparations from kaiphal fruit and bark are kathphaladi kwath, kathphaladi churna, etc. Kaiphal bark is one of the best Indian dye barks for producing yellow colour. The rate for the bark is Rs 25-30 per kg while ripe fruit sells at Rs 30-40 per kg. Cultivation:
This tree fruits profusely almost every year and regenerates on its
own from seeds dropped in birds’ excreta. However, new plants/crop
can be obtained by sowing the seed either directly in the field or by
raising it seedlings in nursery. The species also regenerates from
root suckers and layering. |
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Bird flu: spread and control AVIAN influenza, or "bird flu", is a contagious disease of animals caused by viruses that normally infect only birds and, less commonly, pigs. Domestic poultry flocks are especially vulnerable. The disease in birds has two forms. The first causes mild illness, sometimes expressed only as ruffled feathers or reduced egg production. Of greater concern is the second form, known as "highly pathogenic avian influenza". This form is extremely contagious and rapidly fatal. Birds can die on the same day that symptoms appear. The most important control measures are culling of all infected or exposed birds, proper disposal of carcasses, and the quarantining and rigorous disinfection of farms. The virus is killed by heat (56`B0 C for 3 hours or 60`B0 C for 30 minutes) and common disinfectants, such as formalin and iodine compounds. The virus can survive, at cool temperatures, in contaminated manure for at least three months. In water, it can survive for up to four days at 22`B0 C and more than 30 days at 0`B0 C. For the highly pathogenic form, a single gram of contaminated manure can contain enough virus to infect 1 million birds. Restriction on the movement of live poultry is another important control measure. Source: WHO |
GROWN
all over the country, onion (Allium cepa L) in North India is
severely affected by the downy mildew disease very often, which causes
near devastation, particularly in the seed crop.
The
symptoms of the disease vary with the type of infection. In systemic
infection, the plants remain stunted, become distorted and pale green
in colour. In humid atmosphere, the downy growth of the fungus
develops over the entire leaf surface. However, in dry weather, this
growth is absent and only white spots are seen. Under humid
conditions, sporulation occurs on leaves, which are covered with
felt-like whitish to greyish fungal growth.
KAIPHAL
is a medium-sized broad-leaved evergreen tree of temperate
sub-mountainous tracts. The scientific name for the species is Myrica
nagi. Among its several regional names are katphal (Sanskrit and
Bangla), kobusi (Nepalese), dingsobir (Khasi), udul burk (Persian) and
box myrtle (English). The family is Myricaceae.