In this article we will discuss about the cultivation of temperate fruits. Also learn about the pests and diseases of these fruits.
In India, the temperate fruits are confined mostly to the Western Himalayan region. A very small area is found in the Nilgiri Hills. Many species of these fruits are found growing wild in these regions.
There are many important fruits grown in temperate climates. All of these belong to the family Rosaceae, except nut crops like walnut, which belongs to the family Juglandaceae. Apple is by far the most important fruit in this group. It is the leading table fruit of the world, since it has an attractive appearance, is easy to cut and handle at the table, is not exacting in its climatic and manorial requirements and can be stored at ordinary temperatures for weeks or even months.
Wild crab apple, wild peach (Artoo), wild apricot (Chool or Zardalu), wild pomegranate (Daru), the seeds of which are used as a condiment, some brambles (Rubus ellipticus called Heer or Hinsar), wild strawberry (Fragaria nilgerrensis), found in the Nilgiri Hills, F. indica and a large fruited type called Bhumla found at elevations of about 3000 metres, Kafal or cowphal (Grewia cawa), wild pears locally called Shiara (Pyrus pyrifolia) and Kainth (P. pashia) and many others are found growing at various altitudes.
The wild pear (P. khasiana) found in the Eastern Himalayas very closely resembles the species P. pashia of the Western Himalayas. The Himalayan wild cherry called Paja (Prunus puddum), which is an evergreen tree, is laden with a mass of pinkish white flowers in October and lends great charm to the Himalayan landscape at this time of year. It is different from the deciduous species P. padus, which flowers in spring.
In spite of the profusion of the wild species of temperate fruits found in India, their commercial cultivation in India is extremely limited. India produces about 0.6 per cent of the total world production of 21 million metric tonnes of temperate fruits per annum.
These fruits can be grown only in places where the winter is distinctly cold. Without exposure to a specific minimum chilling in winter, the trees do not flower properly in spring. This is the reason for the lack of success of these fruits in places like Pachmarhi (altitude 1,100 metres) and Chhinwara (altitude 700 metres) in Madhya Pradesh.
The cultivation of these fruits in the Eastern Himalayas is restricted due to heavy rain and high humidity which encourage the incidence of disease and cracking of fruits like cherries, plums, peaches and almonds in the early rains.
Cultivation of temperate fruit is, therefore, confined mostly to the Western Himalayas. Here also every place is not suitable. Localities with frequent hailstorms, which cause shedding of leaves, flowers and fruits spoil the appearance of fruit, and spring frosts, which damage the flowers, are not suitable for fruit cultivation. Sites with poor air drainage also cause damage from cold and are unsuitable. Suitable areas for the cultivation of temperate fruits are, therefore, limited.
Another factor hindering the expansion of the area under these fruits has been the lack of proper transport facilities in these mountainous areas. In the past fruits have often rotted during the rains on account of blockage of roads due to landslides, in places like Kulu and Kotgarh in Himachal Pradesh. The situation is now improving.
The climatic requirements of the different temperate fruits vary greatly apple, cherry and walnut require the coldest climate and are generally cultivated from an elevation of 1,600 metres to 2,700 metres. Pear and European plum thrive at elevation of 1,300 to 2,000 metres. Peach, Japanese plum, apricot, almond, persimmon and strawberry thrive at elevations of 1,000 to 1,600 metres. Some peach and plum varieties grow successfully even in the sub-montane area.
Commercial cultivation of these fruits in India is of recent origin. All commercial varieties have been introduced from abroad. The variety Ambri of Kashmir is considered to be indigenous to India by some people, but this also seems to be an introduction from Central Asia. Commercial cultivation was started by European settlers and missionaries after 1870.
Captain Lee started orcharding in the Kulu Valley and Coutts in the Shimla area. S.C. Stokes started an orchard in Kotgarh in 1917-18. Kashmir was the first State to visualise the great potentiality of fruit-growing in the temperate zone. Its energetic Director of Agriculture from 1910 to 1920, Mr. M. Pychard, who was a Frenchman, introduced many varieties from his native land.
Incidentally, Kashmir was also responsible for introducing the San Jose scale into India. This insect pest was introduced from France in 1906. It almost wiped out the cultivation of apple and other temperate fruits in this State. The State gave free plants to growers in the beginning.
In 1946 it charged only one Anna (1/16th of a rupee) per plant and in 1947 the price was raised to the still nominal level of 4 Annas per plant. The Kulu Valley specialised in a trade of sending apples by parcel post to faraway places in boxes of 10 lb.
In 1945 about fourteen thousand such boxes were estimated to have been dispatched. Even today parcels are sent to distant places like Nepal. At Kandaghat (now in Himachal Pradesh), the Maharaja of Patiala started the cultivation of peaches, plums, etc. under the advice of an American expert, Dr. R.W. Hodgson.
In the recent past, fruit-growing has expanded rapidly in Himachal Pradesh, but it has received a set-back in Kashmir due to the attack of San Jose scale and some diseases. A few apple trees used to be grown near Bangalore in South India at an altitude of 1,000 metres. These have also received a severe set-back due to serious attack of the woolly aphis.
Except for the State of Kashmir, where the majority of orchardists are small farmers, the cultivation of apple has been done in India as a methodical industry. This is due to the good example of the pioneers in the field who were well-educated people and the fact that apple cultivation gave very high returns. As a result of this, the price of land in areas suitable for this purpose has gone very high.
The site for fruit cultivation in the hilly areas should have good air drainage and be free from frost pockets. The soil should be fairly well-drained, medium loam. Apple requires a loamy soil at least 1.25 metres deep with sufficient organic matter in the top 0.5 metres layer.
The presence of lime in the soil is good for apple cultivation. Pears do better on well-drained heavy soils and are less tolerant to drought Plums have the same soil requirement as pear, but can grow on much poorer soils, if plenty of farmyard manure is supplied. The pH of the soil should be about 6.5 to 5.5.
Most of the temperate fruits in India are grown on hill slopes except in the Kashmir Valley and a limited area in the Kulu Valley. On the hill-slopes the planting is done on narrow terraces running along the slopes. The rows of trees run along the hill and not up and down the hill. Erosion of land is a great problem under these conditions.
Clean cultivation is, therefore, not desirable. Combination of cover cropping and sod culture is desirable. Unlike other fruit crops like citrus, apple can grow successfully under sod, provided additional nitrogen required for the growth of the grass is provided. It would be desirable to cut the grass after the rainy season and to spread it under the trees.
It would add organic matter to the soil and also act as mulch. Unfortunately, there is great shortage of fodder in the hills and the general practice in these areas is to cut the grass and remove it for feeding cattle. The basins of the trees are kept free from weeds by four or five hoeing’s per year.
In most of the areas, irrigation is not available except in Kulu and parts of the Kashmir valley. These fruits can be grown successfully without artificial irrigation, provided the natural precipitation is not less than 50 cm per annum. Snow in winter also adds to soil moisture.
Under these conditions, the trees are hand-watered during the first two or three summers. However, irrigation during the fruiting season improves the size of the fruit in plums and peaches. Mulching of the soil under young trees conserves moisture.
When one sees apple trees laden with fruit growing in the scanty soil between big rocks, one wonders from where the tree gets the nutrients to raise the beautiful fruits. Apple and pear require very little manuring as compared to fruits like citrus. They can also draw nitrogen from the soil, even when it is present in very small proportions.
However, some temperate fruits like the peach require higher amounts of nitrogen. According to one recommendation, the temperate fruits are given 4 oz of ammonium sulphate, 4 oz of superphosphate and about 3 oz of sulphate of potash for each year of the age of the tree. For a full-grown apple tree, the maximum dose is ammonium sulphate 5 lb, superphosphate 5 lb, and sulphate of potash 3 lb.
The temperate fruits are easy to propagate. The usual methods are tongue-grafting or wedge-grafting in January- February or shield-budding in summer. In apple, ring budding is also practiced in summer. The trees can be transplanted with bare roots late in autumn. They make good growth in the following spring. Transplanting can also be done in spring.
In Kashmir and the Kumaon Hills, the trees used to be trained in the past in the open centre or vase form, with the lowest branch arising one metre above ground level. This method is useful for European countries with poor sunlight but it is now realised that under Indian conditions, the modified leader system is more suitable. It prevents the breakage of limbs encountered in the former methods.
Pests and Diseases of Temperate Fruits:
Plant protection and pruning form the most important operations in the care of apple orchards.
Woolly aphid (Eripsoma lanigerum) is found in all parts of India and is active from March to December. The pest attacks primarily the underground roots of apple but the winged aphids also attack its aerial parts. It is controlled by the use of resistant root-stocks like Northern Spy and Merton 778, 779, 789 or 993.
Quince, Pyrus pashia, ‘Shiara’ and Cotoneaster bracillaris, found wild in the Himalayas, are resistant to this pest. For non-bearing plants granules of phorate (10-30 g), thimet (10 g) or carbofuran (30 to 50 g) are placed at 5 cm depth in root zones. The aerial forms can be controlled by spraying, with 0.05 per cent methyl demeton, 0.3% dimethoate or phosphamidon.
Biological control with Aphelinus mali, which was introduced in Kulu in 1937, has also been found effective in Kashmir. The ladybird beetle, Coccinella septumpunctata, has been found effective for this purpose in the Kumaon Hills.
San Jose scale (Quadraspidiotus perniciosus) attacks all temperate fruits, but is most serious on apple. It was first found in Kashmir from where it spread to the other areas. The insect lives under a small scale, which appears as a greyish powder on the branches and as pinkish dots on the fruit.
The plant should be sprayed with 0.03% Dimethoate or Phosphamidon to kill the crawlers and newly settled scales in early summer i.e. May and again in the end of September to early October (post-harvest spray). Chlorpyriphos 0.02% or Fenitrothion 0.05% may be sprayed.
The grubs of the root-borer (Dorysthenes hugelli) attack the roots of the plant and can be controlled by applying 0.05% chlorpyriphos or powdered paradichlorobenzene under the soil surface.
Apart from the above mentioned pests, some fungal diseases are also found. Powdery mildew (Podosphaera leucotricha) is a fungal disease appearing in apple orchards every year in Kashmir. Some varieties like Jonathan are especially susceptible to it.
The diseased shoots should be pruned off. This serious disease is controlled by spraying wettable sulphur (0.2 to 0.3%) or carbendazim (0.05%). Stickers like Teepol, Sandovit or Triton must be added in fungicidal suspension. Regular spray schedule reduces the disease.
White root rot (Dematophora necatrix) and collar rot (Phytophthora cactorum) are found under high humidity. Soil aeration and drainage are the remedy for these diseases. In Himachal Pradesh the fungus Phytophthora cactorum causes foot and collar rot in apple nurseries. Black rot (Botryosphaeria quercum), which mainly affects the roots, is found in the Kumaon Hills and Himachal Pradesh.
Apple scab (Venturia inequalis and V. prina) is not as serious in India as in some other countries but the variety Ambri in Kashmir is highly susceptible to it. Lime-sulphur sprays or 0.3 per cent Captan controls this disease.
Stem black (Coniothecium chomatosporum) is the most serious disease of apple in the Kumaon Hills. It enters through the pruning wounds. The affected branches turn jet-black and ultimately die. The pruning wounds should be painted with Chaubatia paste (red lead, copper carbonate and linseed oil (1:1: 250) or copper oxychloride paint or cow dung paste (1 part fresh cow dung + one part clay soil and water to make a thick paste) which provides good healing.
This treatment will also control the pink disease, Botryobasidium salmonicolor, which affects many species especially in poorly-drained soils, and the stem brown disease caused by Botryosphaeria dothidea.
Peach leaf curl is caused by the fungus Taphrina deformans and T. mume. The fungus attacks the leaves of peach which become curled and yellowish or reddish. The internodes become shortened and swollen. It can be controlled with spray of 0.3 per cent copper oxychloride or 0.3 % methyl demeton or Bordeaux mixture before the swelling of buds.
The curling of the leaves of peach is also caused by the aphid (Brachycaudus helichrysi). In this case the leaves do not turn yellowish or reddish. It can be controlled by spraying tobacco decoction before the buds swell.
One of the most common diseases of plum in India is the bacterial gummosis, caused by the bacterium Pseudomonas syringae. It enters through the pruning wounds and causes exudation of gum. It can be prevented by mixing dihydrostreptomycin sulphate in the paste used for covering pruning wounds.
Other diseases of these fruits are the brown rot caused by Monilinia frutigena, sooty bloth (Schizothyrium pomi) and soft rot of the fruit (Penicillium expansium). Spray schedule followed for the management of apple scab provides effective control of these diseases.
The growth of lichens on trees of temperate fruits is sometimes a problem. They smother the dormant buds. Application of one and a half per cent solution of caustic soda to the trees in the dormant season once in five years keeps the growth of lichens under check.