1. 1. By Allah Dad Khan Present Situation of Post Harvest Losses in Fruit and Vegetables
2. 2. Agro climatic condition of Pakistan Agro-climatic conditions of Pakistan ranging from tropical to temperate allow growing 40 different kinds of vegetables and 21 types of fruits. Major vegetables grown in Pakistan include potato, onion, chilli, melons, cucurbits, tomato, turnip, okra and pea, whereas citrus, dates, mango, guava, apple, banana, apricot, grapes, almonds, peach, plum and pomegranate are the main fruit crops. At present area under fruits and vegetables is 0.995 million ha (4.3% of the total cropped area) with the total production of 10.992 million tonnes
3. 3. Magnitude of Post Harvest In Pakistan the magnitude of post harvest losses of vegetables and fruits is about 35%. Efforts are being made both at federal and provincial level to minimize these losses to safe guard the interest of growers, processors, traders, retailers and consumers
4. 4. Postharvest losses These losses may be caused by complete wastage of the product or by lower prices due to a reduction in quality. The cost of these losses is also important as the value of the product increases several fold from the farm gate to the final consumer, so in dollar terms postharvest losses are even more significant.
5. 5. There are generally three main causes of postharvest losses. 1. Disease caused by fungi and/or bacteria 2. Physical injuries due to insects, mechanical force, chemicals, heat or freezing 3. Non-disease disorders resulting from storage conditions that upset normal metabolism when the product is rejected further down the marketing chain .
6. 6. Other factors of postharvest losses In addition to genetic traits, environmental factors such as soil type, temperature, wind during fruit set, frost, and rainy weather at harvest can have adverse effects on storage life, suitability for shipping, and quality. Cultural practices may have dramatic impacts on postharvest quality. Good Agricultural Practices during harvest operations and any subsequent postharvest handling, minimal or fresh-cut processing, and distribution to consumers must be developed.
7. 7. QUARANTINE SERVICES The primary role of the Quarantine Division is to reduce postharvest losses in an effort to ensure that all practices from production to export are strictly adhered to. Any farmer or exporter found violating the system is automatically suspended for non compliance. Farms are therefore closely monitored by the Quarantine and the Extension Departments.
8. 8. Losses in Storage The improper handling, packaging, storage and ransportation may result in decay and production of microorganisms, which become activated because of the changing physiological state of the fruits and vegetables. Fruit, due to their low pH, higher moisture content and nutrient omposition are very susceptible to attack by pathogenic fungi, which in addition to causing rots may also make them unfit for consumption by producing mycotoxins
9. 9. Primary factors responsible for post-harvest produce losses are: poor pre-harvest measures-- adoption of poor production techniques (varieties with low shelf life, imbalance use of nutrients, insect pest and disease infestation and abiotic stresses; low tech harvesting procedures-- non-application of pre-harvest recommended treatments/practices, harvesting at improper stage and improper care at harvest; and post-harvest problems-- non-removal of field heat, dumping produce, moisture condensation causing pathogen infestation, packaging in bulck with out sorting and grading of produce, improper transportation and storage, and distant and time consuming market distribution
10. 10. . In order to preserve the produce quality different post-harvest techniques are recommended for variety of produce. These techniques include; hydrocooling, refrigeration & freezing, modified atmosphere (MA) packaging, MA storage, control atmosphere storage, skin coating, hypobaric or low pressure storage, irradiation, dehydration, canning, high pressure processing and pulsed electric fields and pulsed light applications. In order to promote horticultural industry in Pakistan, standardization of pre-harvest and post-harvest management technologies minimizing postharvest losses and to enhance foreign exchange earning to the maximum extent are therefore essentially required for necessary adoption. At present various R&D institutions are working on different aspects of postharvest management of vegetables and fruits.
11. 11. ADVANCES IN POSTHARVEST TECHNOLOGY AND RESEARCH Selection of varieties for better shelf life Vegetable varieties: Riogrande, Roma AVRDC Cv. (tomato), NARC - 91 (onion), Medium Long Green (chillies), Local Selections (cucumber) and VIP (pea) have shown better transportation quality and longer shelf life. In fruits; varieties: Begum Jangi (date palm), Cardinal, Flame Seedless (grapes), Local Selections (fig), Sultan (pomegranate) and ARS (N) Mingora No. 7, No. 8 & No. 9 (peach) were found high yielding with longer post-harvest life.
12. 12. Influence of rootstocks on postharvest quality of some apples Studies carried out at Deciduous Fruit Development Centre, Sariab, Quetta revealed that on rootstock MM 106, apple cultivars (Red Delicious, Golden Delicious, Star King Delicious and Spartan) showed better performance than on M-9 rootstock for fruit texture and soluble solids. On the basis of organoleptic evaluation or consumers' acceptability' MM-106 showed partially better performance than M-9. For skin colour of fruit, rootstock M-9 showed better results over MM-106. However, rootstock MM-106 should better performance in terms of fruits texture, total soluble solid contents and consumers' acceptability over M-9 rootstock.
13. 13. Pre-harvest application of fungicides Pre-harvest application of Benlate 50 WP minimized mold growth and increased shelf life of citrus (Kinnow Mandrin) at ambient storage temperature.
14. 14. Pre-harvest application of growth hormone GA3 when applied @ 20 ppm on grape Cv. "Kishmish" not only increased the berry size, yield, protein, reducing & non-reducing sugars, pectin and ascorbic acid but also, the mineral contents of berries (sodium, calcium magnesium and iron contents) were increased hence improved the quality of fruits and also its postharvest longevity.
15. 15. Postharvest application of calcium chloride Freshly harvested tomato fruits of variety" Nagina" when dipped in 4% CaCl2 solution and kept at 15oC maintained marketable quality upto 16 days
16. 16. Studies on degreening of citrus and mango Studies on degreening of citrus and mango showed that citrus variety "Salustiana" stored at 30oC and 85-90% RH (controlled atmosphere) developed uniform colour after 24 hours, whereas in case of variety "Honey Mandrine" there was a slight colour development even after 36 hours. In case of mango variety "Chaunsa" stored at 17oC and 80-85% RH after chilling resulted uniform colour development and produced natural flesh taste.
17. 17. Studies on wax coating materials Wax coating studies are being carried out to make the produce more attractive with better shelf life. Carnauba based surface wax increased shelf life of Kinnow 3-4 weeks by delaying senescence. Edible film coatings with gelatin (4%), corn starch (3%), HPMC (3%) and stearic acid (1.5 to 3%) composition enhanced storage life of carrots variety, "T-29" upto 45 days with minimum (10-15%) post-harvest water loss
18. 18. Studies on potato storage Autumn potato crop is the main crop grown in the plains of Punjab. The crop is harvested during the month of January. The produce is kept in the field until the end of February because of low temperature. Thereafter, potatoes are mostly stored in the field in ordinary storage structures, where weight loss, rotting and sprouting of tubers deteriorate the quality of produce. In cold storage the produce is held at 4-5oC. At this temperature starch is converted to sugar and therefore potatoes become sweet. Also, because of high charges of electricity this costs much higher as compared to ordinary storage conditions or storage of potatoes at relatively higher temperature. Studies associated with these problems reveal that: 1. Improved low cost on-farm storage structure (where hot air is replaced by cool air during night using electric fan) the inside temperature was observed 3-4oC low and the stored potatoes retained marketable quality upto 90 days. 2. The sprout suppressant, "Camptothecin" when applied (sprayed) @ 0.5 mM inhibited sprouting of tubers upto 45 days at 39oC, whereas in untreated control sprouting started after 30 days at 39oC. 3. The sprout suppressants CIPC @ 1500 ppm and 2000 ppm, IPC @ 1500 IPM and 2000 ppm and DECCO - 276E (combination of CIPC and IPC) @ 4.4 ml/100 ml water spray checked weight loss, sprouting and sweetening when potatoes were held at 5oC and 9oC storage temperatures and 90% RH until 105 days. 4. Quality of potato tubers when held at 5oC or 9oC and 90% RH was retained until 60 days as the weight loss, rotting, sprouting and sweetening were checked.
19. 19. Studies on tomato fruit storage In case of tomato, variety "Nagina" when dipped in 4% CaCl2 solution and kept at 15oC maintained marketable quality upto 16 days.
20. 20. Quality preservation of apricots Apricots when dipped @ 3% solution of potassium meta bisulphite for 3 hours and then dried proved to be successful.
21. 21. Actors Problems (in order of importance Desirable solutions Producers 1- Lack of irrigation infrastructures 2- Poor access to markets/high competition of imported products 3- Lack/insufficient access to credit 4- Poor access to treatment chemicals and seeds 5- Insects and nematodes 6- Lack of skilled workers (training) 7- Transport and storage 1- Implementation of performed infrastructures for irrigation 2- Credit 3- Proximity and availability of treatment chemicals and seeds 4- Well trained workers Traders 1- Poor access to credit 2- Poor access to markets 3- Lack of traders association 4- Transport and storage 1- Access to credit 2- Training for producers on use of inputs (fertilizers Focus group
22. 22. Suggestions Improved access to high quality seeds (variety shelf life) and other inputs Training of producers on appropriate use of fertilizers and pesticides, the appropriate marketing and production planning methods Improved transport practices, packaging technologies (eg: using folding plastic boxes), improved storage infrastructures Improved access to credit and improved providing policy makers subsidies to producers Training traders on effective and efficient transport or storage practices Monitoring of mycotoxins and pesticides residues