By Zeeshan Sattar, Sabir Hussain Khan, Muhammad Aslam Khan, Iqra Ashfaq and Muhammad Mohsin Raza
THE EARLIEST evidence of grape vine cultivation and winemaking dates back 7,000 years. The genus of grapes is Vitis which contains about 60 species, but the Vitis vinifera is the principal species from the cultivated grapes which has been derived. Dessert grapes, wine grapes and Raisin grapes are three broad divisions of grapes. Grapes are swiftly becoming a popular home grown fruit. They are consumed fresh, as juices and wine, as jam, raisins and jelly Sand as frozen products. European grapes are cultivated for eating in Pakistan. Over 70 per cent of grapes are grown in Baluchistan and some districts of Khyber Pakhtunkhwa with annual production of 122,000 tons having average yield of 19 tons ha against the potential of 25 tons/ ha. Balochistan shares 30 and 14 per cent of the total fruit area and production of Pakistan, respectively during 2000-10. The market value of these fruits produced during 2009-10 is estimated at about 97 billion rupees which is roughly 8 per cent of agriculture value added in the year. Worldwide post-harvest fruit and vegetables losses are as high as 30 to 40 per cent and even much higher in some developing countries. If we have suitable cultivar and weather, then grapes can also be grown in central Punjab. But monsoon rains at the time of berry ripening is the main barrier in successful cultivation of grapes in central Punjab. But grapes can be cultivated absolutely everywhere in Pakistan as a result of localized climatic and soil conditions.
In Pakistan main varieties of grapes which are seedless and they are worldwide famous for their taste and quality these are Sunda Khani, Sra Kishmish, Askari, Flame seedles and King’s Ruby, but some grapes varieties are seeded and these are classified on their growth pattern and the area of cultivation Haita, Black Prince, Sahihi, Hussaini, and Tando these are grown in Pakistan.
Grape vines flourish in most soil conditions because their roots never waterlogged: Stony soil, sandy soil, even clay soil as long as drainage is good, are all ideal for viticulture as grape vine cultivation is correctly known. A deep fertile well drained loamy soil with a moderate amount of organic matter is best for the grapes. On soil low in fertility grapes grow slowly and produce low yield. Heavy clayey soil should be avoided. A pH range from 5.5 to 7.0 is satisfactory. Grape vines need approximately 1300–1500 hours of sunshine during the growing season. The optimum temperature is 22 °C during the growing season, summer that allows the grapes to ripen fully and to develop a balance between the levels of acids and sugars in the grape. Hot and sunny climates have a frost-free growing season of 200 days or more which help the grapes to grow properly.
Generally growing of grape vines were done by propagation and mostly by cutting methods. Take sections of the canes from healthy, moderately vigorous vines while they are dormant. This can be either in late fall or in early spring before growth starts; early spring is preferred because once the cuttings have leafed out and formed roots they can be placed outside, first in the shade, and then planted out in the vineyard. Cut the sections directly from the vine or from brush that has recently been pruned off. Make cuttings three nodes long with the bottom cut (the portion that will form roots) just below the bud or node and the upper cut at an angle of about 45 degrees, ¾ to 1 inch above the bud or node. Place the cuttings with the second bud from the top at soil level and cover with loose soil. After the cuttings have adjusted to the outside environment, they can be planted in the vineyard. It is important not to let the cuttings dry out during this process. Select a location in full sun, or place pots/containers where they get maximum sunshine. Irrigate the vineyard after 10 days intervals during the first summer and 20-25 days after the summer. Fertilizer like N: P: K is very important for the growth of vineyard of grapes early in the winter to maintain the plants. Pruning, which is done in the late winter, is the most importsant operation in grapes culture. Training and pruning depend upon the system you select. Initially your plants should prune to develop a single strong shoot with several well placed laterals. Most common pruning systems in grapes are Head (main stem is trained straight upward), Cordon (main trunk is 2.5 – 3.5 meters long and trained horizontally) and Cane systems (4-6 fruit trunks are raised. These methods were used for pruning of grapes vineyard. Grapes will only ripen on the vine. As they ripen, the sugar content rises to about 20 per cent. Harvest table grapes when the flavor is right; harvest wine grapes when they reach the appropriate sugar content.
Factors responsible for pre-harvest and post-harvest losses
• Both biotic and abiotic factors are liable for the quality of grapes
• The climactic variations in grape-growing regions accounts for the diversity of grapes germplasm.
• Berries quality and other viticulture products.
• Effect of climatic conditions on the chemical characteristics and nutritional quality of grapes.
• Environmental components such as temperature, sunshine, rain, soil and combinations of chemical composition effect on the grapes juice.
• Climate plays an important role for berry maturity, ripening, development of physical, as well as chemical characteristics of the berry quality such as size, colour, aroma, accumulation of anthocyanin.
• Diseases of grapes downy mildew (Plasmopara viticola), powdery mildew (Uncinula necator), grey mold (Botrytis cinerea), anthracnose (Elsinoe ampelina), black rot (Guignardia bidwelli) and crown gall (Agrobacterium vitis) are the major grape diseases which is the main hurdle of grapes vineyard and its production.
• Improper management techniques for grapes vineyards.
• Integrated pest management.
• Primary factors responsible for post-harvest produce losses are: poor pre-harvest measures-adoption of poor production techniques
• Environmental conditions.
• Mechanical damage during harvesting and handling.
• Improper post-harvest sanitation
• Physiological decay
• Poor cooling and environmental control in storage houses
• Non-availability of suitable post-harvest technologies and infrastructure.
• Moisture condensation causing pathogen infestation, packaging in bulk without sorting and grading of grapes.
• Fresh grapes after harvest are either dipped in chemicals or are sprayed with them to kill fungus.
It is estimated that 9 to 16 per cent of the product is lost due to post-harvest problems during shipment and handling. These losses occur not only in developing countries. It is estimated that postharvest losses in developed countries are an average of 12 per cent from production to retail warehouses, and an estimated 20 per cent at retail stores and foodservice sites.
Solution of these problems
• Selection of varieties for better shelf life.
• Modeling cultivating conditions for high quality and long life.
• Pre-Harvest application of fungicides
• Pre-harvest application of growth Harmon.
• Pruning and training in time.
• Scouting of the field for the inspection of diseases.
• Uses of integrated pest management technique’s
• Use sterilized material during all method of handling. Propagation, Pruning. Training and packing.
• Objective determination of suitable harvesting date.
• Post-harvest application of calcium chloride.
• Post-harvest application of chemical increase the shelf life.
• Improves the sanitation, refrigratin and cooling in store house.
• Use fumigate in store house before storing the fruits.
• Fundamental research on senescence, ripening, respiration, ethylene effect, chilling, fermentation, superficial browning
The writers are associated with the Dept of Plant Pathology, University of Agriculture Faisalabad. Theycan be reached at <email@example.com>
Short Link: http://technologytimes.pk/post.php?id=4120