Following are the practices for the good canopy management in grapes
Grape is an important fruit crops, which needs constant attention for the production of exportable quality grapes. The success in grape cultivation depends on the management practices followed right from the planting in case of new plantation and from back pruning in case of old orchards. Canopy management is major practice followed in grape. Some of the practices to be followed in both types of gardens are given below.
Trench opening: This operation should be followed during Dec- Jan month. The trench opened should be in North – South direction. This helps in harvest of maximum sunlight for photosynthesis and fruit bud differentiation. The trench should be of 2’, 6” X 2’,6” so as to get the proper rooting area for root proliferation.
Planting of rootstock: The planting of rootstock should be completed during Feb – March month. During this period, the minimum temperature starts rising above 150 C that helps in enhancing the physiological activity of the plant.
Management of rootstock in field: The rootstock plants after planting in the soil needs to be irrigated at regular interval in its field capacity. In black cotton soil alternate day irrigation is enough however, in light soil the plants should be irrigated daily preferably during morning or in the evening. No fertilizers should be applied till 20 days after planting since the roots are not active and require some time for settling.
Training of rootstock plants and re cut: The rootstock plant once settled in the soil should be allowed to grow as such till 50 days from the planting time. The number of shoots sprouted from each plant helps in increasing the root density. These plants are cut back from the base. The newly sprouted plants having more number of shoots are trimmed and only 2-3 healthy, disease free and vigorous shoots per plants are maintained. The retained shoots are then tied with bamboo with the help of sutali.
Grafting: The grafting is generally done during the month of August – Sept. During this period, the scion material will also be available in the nearby area that can helps in saving the time. During the grafting period, high temperature and high relative humidity prevails in the atmosphere, and the stock plants will also be in the sap flow condition that is a primary requirement of the successful grafting in field. Temperature above 350 C and relative humidity above 80% in along with the grafter’s skill helps in obtaining successful grafts in the field.
Management of grafted vines: The management of the grafted vines in terms of pest and diseases are important since this operation coincides with rainfall and high humidity in the field.
Re- cut of grafted vines: Since the cuttings of scion and also the stock used for grafting will not be of equal diameter that may results in to variation in sprouting or even delayed sprouting. The growth of all the plants will not be uniform. The leaf after certain period will start yellowing and thus falls down from the plant. To avoid this vines are given again fresh re cut. The re- cut of the vine should be taken during the month of February when the minimum temperature starts rising above 150 C.
Developing the framework: Once the re cut is taken the growth of newly sprouted shoot will be much faster that needs to be managed properly so that without wasting of this growth, framework development will be completed at the earliest possible. The cordon development should be done as “Stop and Go” method. In this method, the newly growing shoot is cut at 6-7-leaf stage when it is of 8-9 leaves. Likewise the shoot growth is to be arrested at proper interval and the framework be completed before May so that the fruit bud differentiation will be assured.
Application of FYM: Once the crop is harvested, the vine should be given rest for about 12 to 15 days. However, optimum quantity of water and fertilizer should be supplied to the vines to recoup. A light trench of 2 feet width and 3 to 4 inch depth with the length depending on the distance between two vines should be opened. About 10 kg FYM and 400 – 500 g single super phosphate should be applied in between two vines. The trench is then filled with the soil and earthing up is done so that the root zone gets congenial environment for development of white roots.
Pruning the vines: The vines are generally pruned during 10th to 15th April. Only one or two basal buds are retained and the remaining cane is removed. The process of removal of these canes are called back pruning. Application of Hydrogen Cyanamide though in the small quantity is necessary for uniform and early bud sprout in case of grafted vines. This should also be followed in case of own rooted vines.
Shoot thinning: Once the pasting of hydrogen Cyanamide id done, the new shoots will come out at faster rate. There will be approximately 80 to 100 new shoot on each vine. Retention of all these shoots may results in to heavy crowding for nutrient and water application. Hence, shoot retention should be followed at 4-5-leaf stage. Shoot retention should be based on the purpose of vineyards management. For export purpose, there should be 0.67 to 0.75 shoots per square feet area allotted to each vine whereas for local market it should be 1 per square feet.
Sub cane development: Generally sub cane development is not encouraged in the vineyards. However, the vines basically that are vigorous and also the irrigation water is available in plenty that leads in to vigorous growth, the shoots are pinched at particular position. This is called sub cane development.
Training the shoots: The shoots are trained at proper distance on the wires provided at the particularly distance on the iron angles. This helps in maintaining the proper aeration in the vineyard. Under such canopy the microclimate will not be developed and hence will help the vines to be free from the fungal and bacterial diseases in addition to the uniform cane maturity.
Horticultural Practices to be followed in grape cultivation
|1.||Spacing||10’ X 6’||10’ X 6’||Same for both types of grape growing|
|2.||Area/vine available||60 sq.ft.||60 sq.ft.||-|
|1.||No. of shoots retained/sq. ft.||0.65 to 0.70||1.0||Variation in shoots per vine depends on the purpose|
|2.||No of leaves/shoot (cane)||16-17||16-17||Required for formation of food material|
|3.||Leaf area per leaf||150 to 180 cm2||150 to 180 cm2||Required for photosynthesis|
|4.||Cane diameter (mm)||8-10 mm||8-10 mm||Required to store reserve food|
|5.||Inter nodal distance (cm)||5.0 to 5.25 cm||5.0 to 5.25 cm||This helps in erectness of shoot towards sun that helps in fruitfulness|
|1.||No of shoots/sq. ft.||0.75||1.00||Requires for proper bunch development|
|2.||No. of bunches/sq. ft.||40.0||60.0||To obtain appropriate bunch weight|
|3.||No. of bunches per shoot
|Based on requirement the number of bunches varies.||The cane diameter can decide how much food material is stored to nourish the developing bunch.|
|4.||No of leaves above bunch||10 - 12||8- 10||To protect the bunch from sunlight.|
|5.||Leaf area||150 – 180 cm2||150 – 180 cm2||For proper photosynthesis of that bunch.|
|6.||Total leaves/shoot||16-17||16-17||To supply food material to the shoot.|
|7.||Shoot thinning stage||At 4-5 leaf||At 4-5 leaf||This avoids loss of reserve food|
|8.||Bunch thinning stage||At pre- bloom stage||At pre- bloom stage||This helps in fast bunch development|
|9.||Girdling||6-8 mm berry size stage||6-8 mm berry size stage||It increases the berry size by 1 to 1.5 mm|
|10.||Av. Bunch weight (g)||400||300||Variation in bunch per shoot decides the bunch weight.|
|11.||Yield/vine (kg)||16-18 kg||18 – 20 kg||Exportable quality bunches can be obtained only after retaining appropriate number of bunches per vine.|
|12.||Yield/acre (tone)||12.0||14.0 – 15.0||The yield obtained for local market is higher than the export.|
By: Dr. R.G. Somkuwar