..... Contd...from ... Viti - Culture in India - I
6 Pests and their Management
The important pests of grapes inIndia
Flea beetles: The adult beetles scrape the sprouting buds and eat them up completely after each pruning. Damaged buds fail to sprout. Insecticides like carbaryl at 0.15 percent, quinolphos at 0.05 percent, dichlorvas at 0.1 percent or phosalone at 0.05 percent are sprayed from the fourth day until the emergence of leaves.
Thrips: Thrips attack the ovaries of flowers and newly set berries and suck sap from them. The affected berries develop a corky layer and become brown on maturity. Scab formation on the berry surface is also due to thrip damage to the ovaries/young berries. Such berries are not suitable for marketing. Thrips are effectively controlled by spraying phosphamidon at 0.05 percent, carbaryl at 0.125 percent, phosalone at 0.05 percent or malathion at 0.05 percent. Prophylactic sprays of insecticides against thrips are given once in five days from the initiation of bloom to berry set.
Mealy Bugs: Mealy bugs are the most serious and problematic pests of grapes inIndia India
iii) Release cryptolaemus montrozieri beetles at 8,000-10,000 per hectare when the berries start softening. It is better to release a mixed population of grubs and adults rather than only adults.
Anthracnose is prevalent in all grape growing regions of the country. The disease is characterized by small light brown or greyish black lesions on tender shoots, young leaves, flowers and young berries. Bordeaux mixture at 0.8 percent, copper oxychloride at 0.25 percent or carbendazim at 0.1 percent are used to control this disease.
Downy mildew is the most devastating disease of grapes in the tropical region of the country. The disease mainly appears on the leaves, but also attacks the flower clusters and young fruits. The losses are very high when it attacks the clusters before fruit set. Entire clusters decay, dry and drop down. Properly neutralized Bordeaux mixture at 1 percent, copper oxychloride at 0.2 percent, Mancozeb at 0.2 percent, metalaxyl (Ridomil Mz at 0.2 percent) or Phosethyl-Al (aliettle at 0.2 percent) are used against this disease.
Powdery mildew is prevalent in all the grape growing regions. It is next in importance to downy mildew in its devastating severity. The disease is characterized by the presence of white powdery (ash like) coating in patches on both sides of the leaves, young shoots and immature berries. Powdery mildew is controlled easily by wettableSulphur
Bacteria infects leaves, shoots and berries. The symptoms appear as minute water soaked spots on the lower surface of the leaves, especially along the main and lateral veins. Mostly these spots coalesce and form larger patches. Severely infected leaves give a blighted appearance. Streptocyclin at 500 ppm is used as a prophylactic spray, while Bordeaux mixture at 0.8 percent or copper oxychloride at 0.15 percent is used to check its spread.
8 Physiological Disorders
Physiological disorders associated with high temperature and low atmospheric humidity in the hot tropical region are dead arm and trunk splitting. Salinity injury is common inMaharashtra and north Karnataka. Other physiological
disorders are cane immaturity, water berries, cluster tip wilting, shot
berries, uneven ripening and post-harvest berry drop. The eco-physiological
disorders are ‘coulure’, blossom-end rot, pink berry syndrome, berry
cracking and rotting.
9 Quality Improvement
Shoot and Cluster Thinning: Only one or two clusters are retained per cane depending upon the density of the latter. Irrespective of the number of clusters, only the apical two or three shoots are retained. In vines trained to the flat roof gable, individual shoot length is encouraged rather than the total canopy size for preventing sunburn of the berries.
Production of Loose Clusters: Pre-bloom GA sprays of 10 ppm and 15 ppm are given respectively on the 11th to 14th day after bud break for cluster elongation. Rachides of the clusters are trimmed to retain 8-10, depending on the number of leaves available per cluster. Clusters are dipped in GA solution of 30-40 ppm when 10-20 percent of the flowers open in each cluster for berry thinning.
IncreasingBerry
In addition to the treatment with growth regulators, berry size and crispiness are increased by girdling. The width and depth of girdling are 1-1.5 mm. Girdling is done at 4-5 mm diameter of the berries.
Increasing the TSS Content: Berry thinning and cluster thinning to maintain adequate leaf/fruit ratio (5 cm2), while girdling will ensure a TSS content of 20°B.
10. HARVESTING AND YIELDS
Approximately one million tonnes of grapes are harvested annually inIndia
However, the major proportion of produce, mainly of Anab-e-Shahi, Thompson Seedless and its clones, is harvested during March-April from the hot tropical region, which contributes more than 70 percent of the total harvest.
The productivity of grapes inIndia Hyderabad
7. POTENTIAL FOR GRAPE PRODUCTION DEVELOPMENT
India
c) Scope for double cropping in certain regions and harvesting round the year in certain varieties is practically feasible.
d) Technologies to produce export quality grapes and quality raisins are available.
c) Narrow variety base and lack of diversity in utilization of the germplasm available in grape growing countries.
d) High risk of losing the crop due to unprecedented changes in weather.
e) Soil and water salinity inMaharashtra and drought in the hot tropical areas.
f) Short period available for ripening in the north.
g) Very low proportion of export quality grapes.
h) Wine is not a popular drink at present.
i) Marketing problems in table grapes.
6 Pests and their Management
The important pests of grapes in
Flea beetles: The adult beetles scrape the sprouting buds and eat them up completely after each pruning. Damaged buds fail to sprout. Insecticides like carbaryl at 0.15 percent, quinolphos at 0.05 percent, dichlorvas at 0.1 percent or phosalone at 0.05 percent are sprayed from the fourth day until the emergence of leaves.
Thrips: Thrips attack the ovaries of flowers and newly set berries and suck sap from them. The affected berries develop a corky layer and become brown on maturity. Scab formation on the berry surface is also due to thrip damage to the ovaries/young berries. Such berries are not suitable for marketing. Thrips are effectively controlled by spraying phosphamidon at 0.05 percent, carbaryl at 0.125 percent, phosalone at 0.05 percent or malathion at 0.05 percent. Prophylactic sprays of insecticides against thrips are given once in five days from the initiation of bloom to berry set.
Mealy Bugs: Mealy bugs are the most serious and problematic pests of grapes in
i)
Avoid spraying broad-spectrum insecticides particularly synthetic pyrethroids.
ii) Spray only
dichlorvas at 0.1 percent mixed with neem oil 0.2 percent or tridemorph at 0.1
percent.iii) Release cryptolaemus montrozieri beetles at 8,000-10,000 per hectare when the berries start softening. It is better to release a mixed population of grubs and adults rather than only adults.
7 Diseases
and their Management
The important
grape diseases are anthracnose, downy mildew, powdery mildew and bacterial leaf
spot. In recent years, Alternaria is also becoming a serious pathogen.Anthracnose is prevalent in all grape growing regions of the country. The disease is characterized by small light brown or greyish black lesions on tender shoots, young leaves, flowers and young berries. Bordeaux mixture at 0.8 percent, copper oxychloride at 0.25 percent or carbendazim at 0.1 percent are used to control this disease.
Downy mildew is the most devastating disease of grapes in the tropical region of the country. The disease mainly appears on the leaves, but also attacks the flower clusters and young fruits. The losses are very high when it attacks the clusters before fruit set. Entire clusters decay, dry and drop down. Properly neutralized Bordeaux mixture at 1 percent, copper oxychloride at 0.2 percent, Mancozeb at 0.2 percent, metalaxyl (Ridomil Mz at 0.2 percent) or Phosethyl-Al (aliettle at 0.2 percent) are used against this disease.
Powdery mildew is prevalent in all the grape growing regions. It is next in importance to downy mildew in its devastating severity. The disease is characterized by the presence of white powdery (ash like) coating in patches on both sides of the leaves, young shoots and immature berries. Powdery mildew is controlled easily by wettable
Bacteria infects leaves, shoots and berries. The symptoms appear as minute water soaked spots on the lower surface of the leaves, especially along the main and lateral veins. Mostly these spots coalesce and form larger patches. Severely infected leaves give a blighted appearance. Streptocyclin at 500 ppm is used as a prophylactic spray, while Bordeaux mixture at 0.8 percent or copper oxychloride at 0.15 percent is used to check its spread.
8 Physiological Disorders
Physiological disorders associated with high temperature and low atmospheric humidity in the hot tropical region are dead arm and trunk splitting. Salinity injury is common in
9 Quality Improvement
Shoot and Cluster Thinning: Only one or two clusters are retained per cane depending upon the density of the latter. Irrespective of the number of clusters, only the apical two or three shoots are retained. In vines trained to the flat roof gable, individual shoot length is encouraged rather than the total canopy size for preventing sunburn of the berries.
Production of Loose Clusters: Pre-bloom GA sprays of 10 ppm and 15 ppm are given respectively on the 11th to 14th day after bud break for cluster elongation. Rachides of the clusters are trimmed to retain 8-10, depending on the number of leaves available per cluster. Clusters are dipped in GA solution of 30-40 ppm when 10-20 percent of the flowers open in each cluster for berry thinning.
Increasing
In addition to the treatment with growth regulators, berry size and crispiness are increased by girdling. The width and depth of girdling are 1-1.5 mm. Girdling is done at 4-5 mm diameter of the berries.
Increasing the TSS Content: Berry thinning and cluster thinning to maintain adequate leaf/fruit ratio (5 cm2), while girdling will ensure a TSS content of 20°B.
10. HARVESTING AND YIELDS
Approximately one million tonnes of grapes are harvested annually in
|
Variety
|
Yield (t/ha)
|
Period of Harvest
|
|
|
Average
|
Potential
|
||
|
Anab-e-Shahi |
45
|
90
|
February-May, July,
November-December |
|
|
40
|
60
|
January-March,
June-December |
|
Bhokri |
30
|
50
|
November-December,
June-July |
|
Gulabi |
30
|
50
|
January-March,
June-December |
|
Perlette |
40
|
50
|
June |
|
Thompson Seedless and
other seedless varieties |
25
|
50
|
January-April |
However, the major proportion of produce, mainly of Anab-e-Shahi, Thompson Seedless and its clones, is harvested during March-April from the hot tropical region, which contributes more than 70 percent of the total harvest.
The productivity of grapes in
7. POTENTIAL FOR GRAPE PRODUCTION DEVELOPMENT
a)
Sustaining productivity and minimizing risks in grape cultivation is possible
because of the availability of a variety of agro-climatic regions suitable for
grape cultivation for table, raisin and wine grapes.
b) Technologies
to achieve high productivity are currently available.c) Scope for double cropping in certain regions and harvesting round the year in certain varieties is practically feasible.
d) Technologies to produce export quality grapes and quality raisins are available.
8. CONSTRAINTS IN GRAPE PRODUCTION DEVELOPMENT
Although grape
cultivation is considered as highly remunerative, the area under grapes is
confined to only 34,000 hectares due to the following constraints.
a)
Heavy initial investment for establishing a vineyard.
b) High
recurring costs in vineyard management.c) Narrow variety base and lack of diversity in utilization of the germplasm available in grape growing countries.
d) High risk of losing the crop due to unprecedented changes in weather.
e) Soil and water salinity in
f) Short period available for ripening in the north.
g) Very low proportion of export quality grapes.
h) Wine is not a popular drink at present.
i) Marketing problems in table grapes.