Shramajeevi Wiki
  The Agricultural Information Archive


Grape Cultivation in India

By DR. Venkatramana Hegde, Hosagadde. Director, Shramajeevi Television Pvt. Ltd. Bengaluru

Introduction

Grape is a major and popular fruit of India. Coloured seedless grapes attracted the consumers in a better way in recent years. Farmers are also reaping handsome profit due to modern crop management practices. Grape wine is popular in western countries. But in India major portion of grape is consumed as fresh fruit. A small portion of it is utilized for raisin production. Hence we find grape varieties suitable for table purpose in most of the grape cultivation areas of India. Maharashtra, Karnataka, Andhra Pradesh, Punjab and Tamil Nadu states contribute 90% to the grape production of the country. Uttara Pradesh and Haryana do have some area under grape cultivation.

Grape originates from black sea region below Russia. Available documents say that this fruit was introduced to India in 1300 AD. Mohamad Bin Tuglak brought this crop to South India in 14th century. We get highest yield per unit area than any other country in the world. Average yield in South India is 10 to 14 tons per acre. India stands 2nd after USA in total grape production. But our share in the world trade is negligible. We have a benefit of climate to get good crop for extended period in a season by adjusting pruning dates. Hence there is lot of scope for export oriented grape cultivation.

Soil and climate

Grape prefers dry climate. Temperature ranging from 15 to 40 centigrade and rainfall of 500 to 800 mm is suitable for this crop. Rainy season should not coincide with fresh growth after pruning and ripening bunches. Cloudy climate, high relative humidity, very low temperature and fog are not good at the time of flowering and fruit development. Otherwise the fungal diseases cause major damage to the crop. Sandy loam soil is best suited for grape. Very shallow soil and rock layer below the top soil is not good. Soil pH of 6 to 7.5 is preferred. Grape does not come up well in saline soils. However, grafting on rootstocks like Dog ridge will produce good crop even with high salt content in the soil.

Commercial grape varieties

Thompson Seedless

Even though there are hundreds of varieties in grape Thompson Seedless occupies majority of grape gardens in India. This variety is good both for table purpose and raisin production. The mutant varieties of Thompson Seedless like Tas-A-Ganesh, Sonaka, Manik Chaman etc. are seen in sizable area. Vigorous vine growth, medium sized bunches; closely spaced berries etc. are the characteristics of Thompson Seedless variety. Fruit pulp is firm and very sweet. TSS is around 22 brix. Sonaka variety is a selection from Thompson Seedless and has elongated berries. It responds well to GA3 treatment for elongation. It gives good crop in tropical and mild tropical regions. But Thompson Seedless remains green even after ripening and fails to attract consumers in mild tropical regions like Bangalore.

 

 

 

Sharad Seedless and Krishna Sharad

Coloured seedless variety called Sharad Seedless is becoming very popular in recent years. This is an introduction from Russia. The berries are in black colour and the pulp is firm. It is very sweet and TSS is around 22 brix. Sharad seedless responds well to GA3 application for elongation. There is a selection from Sharad seedless called Jambo Sharad. This variety with big berries is getting popularity in Maharashtra. Another popular selection is Krishna Sharad, a mutant of Sharad Seedless. It has attractive elongated berries and bunches. Farmers prefer this variety in recent years.

 

 

 

 

Flame Seedless

It is a grape hybrid from USA. This adapts very well to high temperature areas and ripens early compared to Thompson Seedless. Vine with vigorous growth gives high yield. Round berries in medium sized bunches will have light red colour. Firm pulp is very sweet and has pleasant flavor. All these coloured seedless grapes are good for table purpose but not for raisin production.

 

 

 

 

 

Red Globe

Bigger and solid berries, big bunches and attractive red colour are the characteristics of red globe variety. But this is a seeded variety. Few farmers are growing this Red Globe and sell it mostly in Super Markets at high price. However, farmers are facing marketing problem to some extent for this variety.

 

 

 

 

 

 

Bangalore Blue

This is an old grape variety native to Bangalore region. This has adapted well to 2 crops a year. Vine growth is limited and bunches are very small. Thick skin and green pulp with seeds are the characteristics of this variety. TSS is around 18 to 20 brix and hence it has sour in taste. Shelf life of the fruit and the disease tolerance of the variety are good. Bangalore blue grape is mostly used for juice purpose and it fetches very less price. According to farmers experience it needs more irrigation.

 

 

 

 

Anab-e-shashi

It is a popular variety in Andhra Pradesh and Karnataka. This is famous for extensive vine growth and very high yield. Bunches and berries are extra large in size. Seeded berries have very less TSS, around 16 to 18 brix. Hence it is sour in taste. But this Anab-e shashi crop comes to harvest very late in the season. Hence it gets good demand and reasonable price after the other varieties are over. This variety is used only for table purpose. There is a mutant of Anab-e-shashi called Dil-Kush. The berries are elongated and seeded. The other characteristics are similar to Anab-e-shashi.

Planting grape vine

Digging pits of 2 to 3 cubic feet for planting of grape plants was the earlier practice. But due to shortage of labor and for better root growth opening trenches with the excavators is common now. The roots spread better due to lose soil in these trenches. Roots spread only in trenches and the interspace is available for movement for cultural operations. Using these machines will save time and to some extent cost also. Add 50 kilograms of compost, 3 kilograms of bone meal, 5 kilograms of oil cakes and 3 kilograms of super phosphate for 30 feet length of the trench before planting and mix it thoroughly.

Lay out of the garden is decided and structures are erected before planting. Let the rows be in North-South direction so that the growing bunches get protection from South-West scorching sunlight in the afternoon hours. Spacing depends on the variety and training method followed. However, the common spacing followed is 10 x 6 feet or 10 x 5 feet. Grape can be propagated by stem cuttings. But grafted plants are common now. Dog- ridge, a rootstock introduced from America is found suitable for Indian conditions and it is widely used for grafting. Rooted dog-ridge cuttings from the nurseries are planted in the main field in January February months. It is grafted in September October months.

Dog-ridge rootstock

Use of grafted plants has become very popular in last 2 decades. Dog-ridge rootstock establishes very well even in moderately saline and poor fertility soils. The root system is strong and performs well with less water. It avoids absorption of poisonous salts like sodium and chloride etc. Dog-ridge maintains balance between vegetative and reproductive growth which leads to good crop. Dog-ridge has resistance against nematodes also. It synthesizes good amount of Cytokinins which helps for better fertility of flower buds. Girdling is not necessary if dog-ridge is used. It is confirmed that the grafted plants give 20 to 25 % higher yield of raisin. Dog-ridge has become a boon for farmers drawing very less and saline water from deep bore wells.

Grafting of grape vine

Nourish the rootstock plant with proper care in the main field. Flood the water in the garden once in a while for better root spreading even if the drip irrigation is followed regularly. Retain only two stout shoots after 4 months of planting. Give bamboo support for upward growth and tie with thread. These plants may show deficiency of magnesium and zinc in the early stage. Correct this by foliar sprays. These rootstock plants are grafted in wedge grafting method in September October months. Select grown up scions with brown skin of 4-inch length, of required variety for grafting. 2 healthy shoots of the rootstock plant with 6-month growth in the main field are retained and rest of the growth is cleared. Give slant cut of 2-inch length on both side of the scion. Cut off the shoot of the rootstock at 1 feet height and make a slit for 2-inch length. Keep the scion in the slit and tie with plastic tape to make the joint airtight. See that the graft joint is at least 1 foot above the soil surface. Joint should not go inside the soil even after earthing up. Graft starts sprouting in 3 to 4 weeks. After confirming the success of grafting after 45 days retain only one good graft at one spot. Grafting is done in the nursery itself in some grape growing countries. But the ready graft takes more time to establish in the main field. For better root and vine growth grafting in the garden itself is advised. Success of grafting is better if the temperature is 25 to 30 centigrade and relative humidity is more than 90%. Hence August September October months are better for grafting. However, the rate of success also depends on the skill of the grafter and the care given to the plant after grafting.

Training of grape vine

Pendal system of training

Training structure is necessary for restricting the growth, pruning and other cultural operations. Pendal structure is in practice in tropical regions since the vine growth is extensive, fast and continuous. But this system is costlier than all other structures. Remove side sprouts on the vine climbing upward and retain only one stout shoot. Pinch the tip of the vine 1 foot below the Pendal. Train 2 sprouts in opposite directions on the Pendal. These branches develop in to primary arms. Side sprouts are allowed to grow at 1 to 2 feet interval on these primaries. These shoots develop in to secondary shots. The shoots developing on these secondary shoots bear crop and are called tertiary shoots. Primary and secondary shoots are retained for many years. Even though this Pendal system is costly, it is better for the varieties like Anab-e-shashi, Dil-Kush and Bangalore blue.

Pendal system of training was followed for all varieties earlier. But the grower has to struggle hard to restrict the growth of the vine. Quality of the crop comes down with slight variation in nutrition. Workers have to depend on chairs to reach the pendal better for different operations. Total labor requirement is more in pendal system of cropping. Leaves overlap on each other increasing in number of yellow leaves. This affects the quality and yield. Development of colour in coloured grapes is slow and uneven. Because of all these reasons grape growers are adapting Y trellis system now.

Y trellis system

Iron angle fabricated in to V shape is fixed to the stone pole to make Y trellis. 3 to 4 GI wires are fitted on both the arms. Attending different operations is easy due to less height which saves lot of labor. Leaves spread systematically and hence all the leaves get enough sun light. These leaves provide good protection for growing bunches against scorching sun. Crop comes to harvest 15 days early in Y trellis than in pendal system. Yield and quality of crop is also better. Bunch comes down itself saving the labor cost for tying bunches. Spray liquid reaches all the leaves and bunches uniformly. This enables effective control of pest and diseases improving quality and yield. H system of training with 4 arms is better in Y trellis system. Cost of erection of this is less compared to pendal system. This system of training provides enough scope for mechanization in vine yards.

Pruning of grape vines

The flowering buds develop in the mid portion of the canes. The fertile buds will not open properly if the growth of the shoot is continuous. It will result in poor crop. To enable proper flowering pruning is quite essential. Vegetative growth of the grape vine is limited in North India due to severe winter. Hence pruning once in January is sufficient. But in South India growth of the vine is continuous and vigorous. Hence it needs pruning once in winter and again in summer. Summer or April pruning is called as back pruning, while winter or October pruning is called as forward pruning. The grape vine enters rest period after April pruning and develops fertile buds. Tender growth after pruning should not receive rain and the winter should not commence before 10 days after pruning. Fix up the date of pruning so as to avoid these situations.

Summer pruning is done in March April in Maharashtra, Andhra Pradesh and Karnataka and in June in Tamil Nadu. Only one or two buds of tertiary shoots are retained on secondary shoot in back pruning. These buds give out healthy and stout shoots. Winter pruning is done in last week of September or before October end. December month is the right time in Tamil Nadu. Shoots grown for 6 months after summer pruning are pruned to the required length. Number of buds on the shoot to be retained depends on the variety and the thickness of the cane.

Most of the growers get two crops in a year in Bangalore Blue in Karnataka and Pachadrakshi and Anab-e-shashi in Tamil Nadu. In this case forward pruning is done again in summer instead of back pruning. In an another practice Bangalore blue garden is divided in to blocks and pruning is done at different time to extend the cropping period. In double cropping system the quality of the grape is low due to over exploitation of the vine even though the total yield is more. It increases pest and disease build up also. Hence one crop per year is the best practice.

Pruning is an important operation which needs decision making and accuracy. Heavy pruning or retaining less cane gives less yield. But the quality of the crop will be better. Light pruning or retaining more shoots will result in heavy crop but of lesser quality. One can go for light pruning if the vine growth is excellent in good management condition with sufficient nourishment and irrigation. But heavy crop on a poor vine will result in necrosis of bunches and many more problems. This affects the marketability of the bunch.

Medium or less crop is advisable if the last season crop was heavy. Grape vine has its own limitation to nourish the bunch. One may retain more number of canes for flowering on healthy vines with vigorous growth. Go for heavy pruning of weak vines. All the canes will not flower equally. Canes away from the main trunk are more fertile. Hence you may retain more number of canes. Retain fewer canes near the trunk. Partially grown green canes, tapering canes, flat canes, canes with long internodes will not bear flower. Hence cut them off at the base itself. It is better to retain lengthier thick canes and shorter thin canes for optimum crop. As a thumb rule do not retain more than 1 cane per 1 square foot area.

Sub-cane technique

One more special method called sub-cane technique is practiced now. It has revolutionized grape cultivation. Here the shoot is pinched off after 5 leaves after 30 to 35 days after back pruning. One or two sub canes are allowed to grow on this main cane. This restricts lengthy growth of the main cane. The buds on the middle portion of the cane develop flower primordial. This helps for better decision making during forward pruning resulting in better crop. This technique also avoids retention of unnecessary lengthy shoots.

Use of hormones

Use of various hormones is extensive in grape than in any other crops. But one should be very careful about the stage of use and the concentration of these hormones. We find the problem of bud breaking in some varieties of grape after October pruning. Smearing 2% Thiourea or Hydrogen cyanamide called Dormex is helpful to overcome this problem. This hormone solution is applied to last 3 buds of the canes with the help of cotton swab. To restrict the vegetative growth of the shoot Lihocin or CCC is useful. This increases the chance of fertile buds. Gibberellic acid or GA3 application reduces number of flowers and also results in elongation of berries and bunches. Hormones like Combine, BA and CPPU increase the size of berries. The schedule and the concentration of different hormones for balanced crop, quality bunches and berries are like this-

Days after pruning

Stage of bunch

Hormone

Concentration (ppm)

A. 21 - 23

Early bloom

CCC

250

B. 28 - 30

Pre-bloom

GA 3

10

C. 32 - 35

Full bloom

GA 3

20 - 25

D. 40 - 42

Post set

GA 3

30 - 40

E. 45 - 50

1 week later

GA 3 + Combine(BR)

25 + 1

F. 50 - 55

1 week later

GA 3 + Combine(BR)

or BA

25 + 1

5 - 10

 

Use CCC if and only if it is necessary. Decide the amount of flowers to be retained and use GA3 hormone may be for 3 times. Do not use GA3 if the climate is cloudy. Otherwise excess flower shedding may affect the yield. Do not use GA3 from full bloom stage till the fruit setting completes. Combine hormone is in alcohol medium and can be mixed directly with GA3 and applied together. Stop using hormones before 1 month of harvest to avoid chemical residues in the berries. Hormone application will not bring any result if the nourishment to the vine is inadequate. If sufficient quantity of organic manure and oil cakes is provided the development of bunches and berries will be good even without hormone application. All these hormones may be applied by spraying or dipping bunches. Spraying is easy and consumes less labor. But the reach of the solution to all bunches and berries will not be uniform. However due to labor shortage most of the farmers follow spraying for hormone treatment.

Nutrition to grape vine

Nutrient requirement for grape vine depends on variety, soil type, climatic condition, quality of water and age of the vine etc. Deciding the dosage of nutrients based on soil, water, leaf and petiole analysis will avoid unnecessary application of fertilizers. Further the absorption will be better if the fertilizer is given through irrigation water. Nitrogen increases vegetative growth. Excess nitrogen reduces flowering and hence number of bunches. Phosphorus is useful for flower bud initiation. Potash is helpful for the maturity of the canes, sufficient flowering and better berry quality. Excess dosage of any one nutrient will affect the absorption of other nutrient. 120 kilograms of Nitrogen, 120 kilograms of Phosphorus and 320 kilograms of Potash per acre per year is the general recommendation of fertilizers for grape crop. Absorption will be better if the fertilizers are applied in a ring 2 feet away from the base of the vine. Use of nitrogen in the form of Calcium Ammonium Nitrate after pruning and Urea afterwards is recommended. It is better to avoid Ammonium Sulphate since it increases the acidity of the soil. Use potash in the form of Sulphate of Potash. MOP may cause chloride toxicity in grape. Flower bud initiation takes place in 40 to 45 days after summer pruning. Analyze the leaf or petiole at this stage to know the nutritional status of the vine. This helps for the adjustment of fertilizer dosage leading to better crop and yield. Micronutrient deficiency is not a major problem in grape. Hence take up corrective measures if and only if the deficiency symptoms are seen.

Water requirement for grape vine depends on soil type, climatic condition and crop stage etc. Excess irrigation leads to increased chance of fungal diseases. Graft plant on dog ridge rootstock needs less water. Drip irrigation is better for optimum water supply. Even we can give soluble fertilizers through drip irrigation. Hence most of the farmers follow this system. Fertigation dosage and the schedule is like this

Fertigation schedule after April pruning

Days after pruning

Kg/Day/Acre

N : P : K

Total no. of days

Total (Kg/Acre)

N : P : K

8 - 40

0.5 : 1.0 : 00

33

16.5 : 33 : 00

41 - 75

00 : 0.5 : 0.5

35

00 : 17.5 : 17.5

76 - 90

00 : 00 : 0.25

15

00 : 00 : 3.75

 

 

Total

16.5 : 50.5 : 21.25

 

Fertigation schedule after October pruning (during growth period)

Days after pruning

Kg/Day/Acre

N: P : K

Total no. of days

Total (Kg/Acre)

N: P : K

08 - 35

0.5 : 0.5 : 0.5

28

14 : 14 : 14

36 - 75

0.5 : 00 : 1.0

40

20 : 00 : 40

76 - 90

00 : 00 : 1.0

15

00 : 00 : 15

91 - 120

00 : 00 : 0.5

30

00 : 00 : 15

 

 

Sub Total

34 : 14 : 84

 

 

Grand Total

50.5 : 64.5 : 105.25

 

Weed control

Manual weeding is better. Otherwise one may use small tillers for inter-cultivation. Mulching is also a good practice. We may use pre-emergent herbicides like Diuron, Simazine or Atrazine at the rate of 800 grams a. i. per acre. Otherwise spray post emergent herbicide like Glyphosate at the rate of 10 ml per liter of water with 5 grams of Ammonium Sulphate and soap. It keeps the weed under control for long time.

GAP for quality grape production

Now let us study some important points for good quality grape production. Farmers producing grape raisin are not bothered much about the shape and size of berries or bunch. But these are important for growers selling fresh fruits especially coloured grapes. Variety, size of the bunch, number of berries in a bunch, size and uniformity of the berries, colour, absence of scares on the berry etc. are the important features of quality of grapes. Amount of sweetness and sourness, absence of chemical residues etc. decide the taste of grapes. Firmness of pulp, extent of ripening and post-harvest handling etc. decide the shelf life of the fruit.

Bunch size

Bunch with 300 to 700-gram weight is the optimum size. Apply 75 to 80 kilograms of nitrogen per acre for better vine development at 35-day stage after summer pruning. This increases bunch size. Keep one fruiting cane per 2 square feet area. Stop the growth of the shoot at 15 to 18 leaves. To achieve this pinch the shoot tip or spray CCC at 75-day stage after back pruning. Application of 100 to 150 kilograms of SOP per acre at 60 to 90-day stage will increase cane thickness and hence the bunch size. Avoid the incidence of powdery mildew disease. Prune the shoots with thickness below 6 mm diameter. Do not retain more than 15 leaves on fruiting cane. Pinch the shoot tip at pea size berry stage. Do not retain bunch on the cane with less than 8 leaves. These efforts yield bunches with good size.

Size of berries

Size of the berry is also an important feature of quality. This depends on variety, presence or absence of seed, amount of GA3 hormone used and leaf area nourishing the bunch etc. More number of berries in a bunch leads to small size of berries. These berries may crack or decay at ripening. Hence take up thinning. Extent of thinning is based on experience. As a thumb rule retain 8 berries for a leaf with 6-centimeter width. Finish thinning work before the berries grow in to pea size. Treat the berries with 25 ppm GA3 with 10 ppm BA or 1 ppm Homobrassinolide or 2 ppm MCP once at sorghum size of berries and once again at pea size of berries. Do not restrict irrigation from 60 days to 105 days after October pruning. Apply sufficient amount of nitrogenous fertilizer to reach required leaf area. These efforts will improve the size of the berries.

Uniformity of berries

Uniformity of berries in shape and size is also important. 25% portion of the bunch at lower end may be cut off for this purpose. Take care while treating with GA3 so that all berries get the treatment uniformly. Uniformity of colour of the berries is also an important factor. Inadequate nutrition, too early pruning, very high or less than 8 centigrade night temperature at the time of ripening will lead to uneven berry colour. Let the alignment of the rows be in North-South direction in Y trellis system. Ensure at least 10 leaves per growing bunch irrespective of leaf size or area. To avoid pale red colour berries spray 0.2% Ascorbic acid and 0.25% Sodium Dithiocarbonate mixture at 15-day interval from 100-day stage after October pruning. Avoid winter pruning in last week of September and 1st week of October.

Scars on the berries

Scars on the berries affect the look and hence the marketability of the bunch. Avoid the chance of Anthracnose disease between 45 to 60 days after October pruning. Thrips insect should not attack between 30 and 50-day stage. Avoid powdery mildew disease between 45 and 105 days. Do not spray any chemical especially Bordeaux, Sulphur and Kerethane from fruit setting to pea size berry stage. These chemicals leave scorching scars on tender berries. Keep on stirring the spray solution in the tank. Otherwise the concentration of the chemical becomes high at the bottom of the tank resulting in scorching effect. South west sun in the afternoon will have scorching effect on growing bunch. Leaves should give protection to the bunch against direct son. Protect the rows along the road with shade net.

Sweetness of the berries

Sugar content or TSS of the berry is another important quality component. Sufficient sunlight and ventilation to all leaves will improve sugar content in the fruit. Avoid bunch on weak canes. Regulate the crop by thinning excess bunches and berries. Sourness depends on variety, extent of ripening and temperature. Sourness comes down as and when sweetness improves. Grape tastes good even with high sourness if the sweetness is high. Even though the sugar content is the varietal characteristics, it varies with the crop load on the vines; ratio of leaf area and number of bunches and availability of potash etc. Grape harvested in summer will be sweeter and less sour. Stop irrigation before harvesting.

Chemical residues

Harvested berries should not have chemical residues. Apply all possible organic methods in the vine yard. Do not violate the safety period of any pesticide. Avoid sprays at the time of harvest. Only mealy bug is found at ripening stage. Use chemicals with 5-day safety period for its control. Stop indiscriminate usage of fertilizers and pesticides. Especially nitrogen should not be applied at ripening stage. Berries should not detach from the bunch after harvest. Treating the bunch at growing stages with 10 ppm BA or 1ppm Homobrassinolide will strengthen the stalks of the berries. Treating with 50 ppm NAA before 10 days of harvest will minimize shedding of berries from the bunch. Grape vine should not face water shortage and do not spray Ethrel at harvesting stage.

Export of grape

India stands 2nd in grape production next to USA. But our share in the international trade is less than 1%. Chile is the competitor for our grape. Thompson seedless and Tas-a-Ganesh varieties have very good demand in European markets. Sonaka and Sharad seedless are preferred by Gulf countries and Bangladesh. Sri Lanka, Singapore, Malaysia and Moriches prefer Sharad seedless and Tas-a-Ganesh. Farmers interested in exports should concentrate on quality than quantity. European market standards are very strict and the price is decided based on quality only. Our grape growers are not happy about severe thinning for big berries and restrictions on use of various chemicals for export oriented crop. Fresh fruit and raisin are fetching good demand and price in the domestic market itself. Hence this export business is not an attractive option for our farmers. Only Maharashtra farmers are exporting fresh grapes on small scale now. However, there is absolutely no problem for growing export quality grapes in our country. The same story lies with grape wine as well. Selling grape wine is a major problem. Most of the grape wine units are suffering loss and are about to close. Yield and the factory price for wine variety grape is too less. Hence most of the growers uprooted these wine grape plantations. Looking to this situation we have not elaborated wine grape cultivation and export of grapes.

Diseases of grape

Grape vine consumes 50 to 60 sprays of different chemicals annually. Most of the sprays are for the control of fungal diseases. Systemic fungicides have brought down the frequency of sprays in recent years. Now let us study few major diseases of grape crop.

Downy mildew disease

Plasmopara viticola fungus is the causal organism of downy mildew disease. Cool-humid climate with frequent rain will encourage this disease. This is common between July and December months. White fungal growth is seen on the lower surface of the leaf. Corresponding upper surface of the leaf shows yellowing. Leaf dries up slowly and drops. Even the flowers and tender berries are affected if the infection is severe. Flowers wither and berries become water soaked, pale yellow, leathery and drop. Spray 1% Bordeaux mixture immediately after pruning. Spray 0.4% COC or 0.2% Mancozeb or Kavach solution once in a week in July August months and once in 3 to 4 days in November December months. We can use systemic fungicides like Ridomil MZ, Matco, Curzate or Aliette at the rate of 0.2 % once in 10 to 15 days. It can control Downy mildew disease effectively.

 

Powdery mildew disease

Uncinula necator fungus is the causal organism of powdery mildew disease. Cloudy atmosphere in dry winter encourages this infection. This disease is common in December-January-February months. Powdery growth develops on upper leaf surface, tendrils and berries. Affected young berries do not develop properly, become hard and crack. For the control of this powdery mildew disease, spray 0.2% wettable Sulphur or dust 7 kilograms of Sulphur per acre once in 5 to 7 days in December-January-February months. Otherwise spray systemic fungicides like Bayleton or Systhane at the rate of 0.1% or 0.5% Rubigan or Topaz once in 10 to 20 days for effective control of powdery mildew disease.

Anthracnose disease

Anthracnose of grape is caused by a fungus called Gloeosporium ampelophagum. Coloured grape varieties have resistance against this disease. This problem is common in rainy season between July and November months. Dark brown coloured spots are seen on tender shoots, leaves and tendrils. If the infection is severe the shoots curl and leaves become perforated. Birds eye shaped lesions are seen on berries. Spray 0.1 % Bavistin or Methyl Thiophanate, Baycor or 0.2% Quintal once in 10 to 15 days between June and November months. Spraying garlic oil is also found effective. Apart from these major diseases take up control measures against leaf spot, rust and other problems as and when it is necessary.

Insect pests of grape

Insect damage is very less in grapes. Flea beetle attacks fresh leaves after pruning. Leaves show cut holes. Spray 0.06% Quinalphos or 0.2% Carbaryl after 4 days of pruning. Neem cake extract is also effective.

Mealy bug

Mealy bug is found in the vine yards from flowering stage to harvest. Nymphs and adults suck sap from tender shoots and berries. Sooty mould develops on those parts which affects the appearance. Shoots and leaves curl if the infestation is severe. As a control measure remove loose bark on the canes which shelter mealy bugs. Mix 6 grams of Carbaryl, 2 ml Neem oil and 1 ml gum in 1 liter of water. Paint this mixture to all thick canes. If curling of leaf is seen, spray 0.05% Dichlorvos once. Then spray 0.05% Phenthoate. Even the predators may be used for the control. Mealy bugs are seen here and there in the garden in the beginning. Hence it can be picked and destroyed before spreading to the whole vine yard.

Thrips and Ambrosia beetle

Thrips damage is also seen in grapes. If it sucks sap from tender berries, the scar remains affecting the look. Thrips infestation on tender leaves results in curling of leaves. Spraying 0.06% Dimethoate is recommended for the control. Apart from this, stem borers like Ambrosia beetle attack the grape vines. Holes on the stems and wood powder are the symptoms of the presence of this stem borer insect. Vines turn yellowish and dry if the infestation is severe. But the vine takes 15 to 20 months to die. To avoid stem borer, remove loose barks and keep the garden clean. Spray the stems with 0.25 % Dichlorvos insecticide. Or inject the same solution in to the hole with the help of syringe and plug the hole with cotton.

Harvesting and Packing

Grape bunch is harvested when it is fully ripe on the vine itself. Normally it takes 120 to 140 days after pruning. Lover most berries on the bunch become soft and sweet at ripening of the bunch. Green variety grape turns to light yellow colour while the coloured grapes turn to dark colour. Few varieties develop aroma also. To improve shelf life, stop irrigation before harvest. Harvest the bunch in morning cool hours as far as possible. Clean the bunch by removing damaged and rotten berries. Grade the bunch according to the quality. Carton boxes are enough for local markets. But for distant markets use plastic crates like this to avoid post-harvest losses. In case of Red globe grape consumer packs of 1 or 2 kilograms are done and sent to super markets. Vine yards near big cities can earn more profit by these efforts and with farm fresh quality.

Farmers away from consumer markets normally go for green grapes like Thompson seedless, Sonaka etc. These varieties perform very well in hot climates. Growers sell fresh fruit as well as dry grape or raisin. Raisin making is more profitable in recent years. Big farmers go for drying themselves. Small farmers go for hired sheds. In dry climate grape drying is very fast and the quality of the raisin is also excellent.

Raisin making

There are 2 methods of raisin making. But most of the farmers follow Ethyl oleate method. Green seedless grape with thin skin and more sugar content is suitable for raisin production. TSS should be between 22 and 24 brix. Grape bunches for this purpose is harvested late after confirming high sugar content. Clean the bunch by removing damaged, cracked or diseased berries. Wash the bunch in clean water thoroughly. Put 1 liter of Ethyl oleate and 2 kilograms of potassium carbonate in 100 liters of water. Immerse the grape bunches in the solution for 3 to 5 minutes. Then drain the solution and spread the grape bunches on shelves in the shed under shade. Temporary sheds are covered with shade net while the permanent ones will have regular roofing. There is a provision to spread plastic sheet at the top to protect the drying berries from unseasonal rain in the temporary sheds. Permanent shed keeps good for 20 to 25 years. In principle drying needs clean dry shade without dust but with good ventilation. The same preservative solution used earlier for dipping is sprayed 2 to 3 times in the process of raisin making. We get good quality raisin in 15 to 20 days in this method.

Grape berries in the bunch remain intact till they dry. 2 GI pipes are put on either side of the mesh and moved. Dry berries get separated and drop down. It is cleaned with the help of a machine and dry stalks, debris etc. are separated. At the same time, it is graded according to the size. Again it is cleaned and graded manually and packed in carton box with poly cover. These boxes are kept in cold storage at 3 to 5 centigrade to avoid fungal growth. Normally these storages charge 50 paisa per kilogram per month. Farmers take out the raisin boxes whenever they want to sell. Grape raisin from hot regions of the country is of excellent quality and exported to Gulf countries. Delhi is the biggest market in India for grape raisin.

Yield, Income and Economics

Growers are earning handsome income in recent years either from raisin making or fresh grape. Initial investment for the establishment of vine yard is around 3 to 3.5 lakh INR per acre. One can expect commercial crop from 3rd year. Total spending on one-acre grape garden till first harvest will be around 8 to 10 lakh INR. We can expect good crop for 15 years. Annual expenditure for general maintenance, chemicals, manures and fertilizers etc. is around 2 to 3 lakh INR per acre. Well maintained garden will yield 12 to 15 tons of fresh grapes per crop. 3 to 3 kilograms of fresh grape yields 1 kilogram of grape raisin. Raisin of first quality fetches INR 150 to 180 per kilogram. Fresh green grape like Thompson seedless sells for INR 40 to 50 per kilogram. Coloured seedless grapes of Sharad seedless and Krishna Sharad variety fetch INR 70 to 80 per kilogram. The special grape varieties like Flame and Red globe sell at still better price. At present grape growers are earning a net profit of INR 3 to 4 lakh per acre per year.

Grape is a dry zone crop. Irrigation water is a scarce resource. Water table is going deep and deep every year. Availability of labor is a major problem again. Even then the grape growers are happy because of their net earnings. Future is bright if they judiciously use the ground water, fertilizers, chemicals and other resources and grow good quality grape. Grape has wide market and there is enough scope for area expansion. Even the research support for grape is better than any other crop. We can expect still better performance from our grape growers in coming years. Namaskar.