HOW TO SAVE POST-HARVEST LOSSES?
Feb 09 - 15, 2009
Post harvest losses of fruit and vegetables are very high in Pakistan. These are estimated to be about 35-40 percent of the total production.
CAUSES OF POST-HARVEST LOSSES: These losses are caused by unscientific and careless cultivation, lack of vigilance of the crops and gardens, reckless harvesting, unskilled picking, packing, rough handling, and unsafe transportation of the stuff, which is mostly done loosely in tractor-driven trolleys, trucks, pick-ups instead of carrying them in safe containers and refrigerated vehicles. The fruit and vegetables get damaged on the way to the whole-sale markets due to rough handling and bumpy and broken roads, as they constantly receive jerks, which result in collision of vegetables and fruit with each other. Due to damage and injuries the quality of the products deteriorates and these are discarded or downgraded by whole-sale dealers and Ahrtis. The ultimate sufferers of this loss are small businessmen and farmers, who do not get reasonable price of these products in the market.
It has been observed that farmers, for one reason or the other, delay picking and plucking of fruit and vegetables till such time as they become over-ripe and on reaching the markets and onto retail shops, they turn stale and get decayed. It has also been observed that over-ripe fruits drop on the ground and get damaged.
Birds like parrots, crows, sparrows and animals like rats, squirrels, rodents, rats and insects also cause significant losses. Therefore, orchards and vegetable gardens in the fields need a constant vigil, watch and care by farmers and gardeners in order to save them from these animals and are in good condition when they are marketed.
Readers would agree with the scribe that these losses and deterioration of quality of fruit and vegetables contribute to human hunger, poverty, price hike and inflation in food products. Reducing post harvest losses is, therefore, extremely necessary for ensuring supply of sufficient food, both in quality and quantity, to every inhabitant on this planet. Naturally, improved harvest practices result in reducing food losses, improving overall quality and food safety. Resultantly growers and marketers get higher prices of their produce. On the other hand, bad harvest timing, defective and inefficient machinery, carelessness, attack of birds, rats, squirrels, moulds, bacteria, contaminants, heat, cold, moisture and lack of moisture continue to cause losses.
LOSSES OF STAPLE FOOD CROPS: According to a study conducted by the United States Research Council, post-harvest food losses are enormous. It has been observed that crops that are allowed to stand far too long in the field become victims of rodents, grain eating birds and molds, which cause physical deterioration of the produce. It has also been observed that while threshing and milling, the grain may not be effectively and safely separated from the plants and impurities may cause deterioration of the quality.
International Research Institute of Philippines (Irri), as a result of a study conducted by them, has estimated that 5 to 16 percent of rice is lost during harvesting, handling, threshing and cleaning. Another 5 to 16 percent is lost during the process of drying, storing, milling and processing. Total losses excluding subsequent losses by retailers and consumers may range between 10 to 37 percent of the entire yield of rice. Finally considerable losses may occur in washing and cooking.
Shattering of grain in the field at the time of harvesting may cause 5 percent loss to the crop.
Another common loss is that grain is left on the stalks, for example during the paddy threshing by beating about 12 percent losses occur. When these stalks are burned, it leads to complete loss of the leftover quantity of rice, however, when the stalk is fed to animals, loss is partly recovered in the form of milk and meat of the animals.
In case of wheat crop, a good quantity of wheat falls to ground when harvesting is delayed due to the blowing of strong wind and wind storms. Floods and heavy rainfalls also cause heavy damage and loss when cereal and wheat crops are ready for harvesting. Leakage and seepages of adjoining water channels and canals also cause heavy losses to the harvested and the crops waiting for harvesting in the field.
Drying of a grain crop is necessary to prevent seed germination and possibility of attack by insects and mites and to cut moisture in order to avoid growth of fungi and bacteria, however, over-drying has also a disadvantage as it causes seed coat break. Damage to grain in stores is minimized with the application of cool, dry air and clean containers. It may also be ensured that new and old stores should remain separate and apart and both of these types of stores must be at a safe distance from fields in order to secure them from concentration of insects.
The post harvest losses for crops range from 13.5 percent in case of grains and 35 to 40 percent of fruits and vegetables. Shattering of grain in the field at the time of harvesting may cause 5 percent loss to the crop.
NUTRITION LOSSES: Nutrition losses are of two different kinds. The first may be due to insects or micro-organisms. These can cause considerable loss of vitamins and protein. Secondly, infested wheat may have a 38 percent loss in food value after keeping it only for 14 weeks in storage.
HARVESTING METHODS OF FIELD AND HORTICULTURAL CROPS: In Pakistan sickles and knives are commonly and traditionally used for harvesting of field and horticultural crops. With the advent of time, the use of machinery like tractor drawn combined harvester or reaper is also becoming popular for harvesting crops of rice and wheat etc. However, these machines are not within the reach of small farmers. They usually and mostly do this job manually and collect the crops in bundles and vegetables and fruit in baskets and transport them to threshing and grading places.
Advisably clippers should be used to remove fruit from the fruit bearing trees. On the other hand usually fruit is pulled manually by hand but there is a constant danger that the stem may be pulled out of the fruit, damaging the skin or damage may be caused to the tree, providing an entry point for field diseases. As a precautionary measure, not more than 0.5 centimeter of stem should be left attached to the fruit. If and when the fruit is mature or ripe, these pieces of stems will dry up and fall off, leaving only a flower calyx (buttons) attached to the fruit. As soon as fruit is harvested, it should be placed in a fruit bag worn by harvester or placed in plastic buckets instead of placing or throwing them on the ground carelessly.
FIELD HANDLING: Harvested fruit should be consigned to harvesting containers, from where it is emptied into field containers. At this stage fruit should be protected from the sunlight and rain while waiting for packing or moving to the packing place.
SELECTION: Before fruit is packed, foreign material like leaves and twigs should be removed. Then it should be inspected and pieces, which are found un-ripe, immature, under sized, damaged, injured or decayed should be removed, which should be sent to local processing cottage industries for preparation of jams, sauces and pickles.
MARKETING: It is observed that small farmers, who produce most of the crops, fruit and vegetables in developing countries like Pakistan lack an easy and effective access to markets because of inadequate and broken roads and reliable transport, as also financial resources. They also do not have proper and effective preparation arrangements and facilities for marketing of their produce. Similarly they do not have harvesting techniques and sound and safe ways. Another crux of the problem is that they lack control over pricing. That is why the middle man and traders skim most of the profits and small farmers are left with a nominal profit.
HOW TO REDUCE HARVEST LOSSES: An effective programme for small farmers should consist of a package of technical and logical proposals. Agriculture Extension Department should itself be well equipped with knowledge and up-to-date technologies to train and guide our farmers to achieve higher production qualitatively as well as quantitatively and market prices by improving the quality of their produce.
The bottlenecks for post harvest losses are mainly due to:
a) Low standard of education of farmers
b) Inadequate number of horticulturists
c) Lack of awareness amongst farmers about field crops and horticultural crops
d) Lack of availability of published/written material both in vernacular language and Urdu for the guidance of farmers
e) Lack of in-depth knowledge of suitable varieties, cultural practices, harvesting and packaging techniques among farmers
The responsibility lies with the government which has so far failed to produce progressive farmers and well trained horticulturists and extension workers to help growers and gardeners to improve upon their pre-harvest and post-harvest techniques and technologies, crop care, packing, packaging, transporting and marketing. Awareness can be created through extension workers and agriculture experts through presentations, demonstrations and seminars. The present government of Punjab under the dynamic leadership of Mian Shahbaz Sharif, Chief Minister is keenly interested to bring a revolution in the agriculture sector in Punjab and it is sanguinely hoped that he would be successful in making a good headway in this sector for bettering the lot of people belonging to this sector in Punjab and setting good precedents for other provinces to follow.