The Sunday Mail
Word From The Market with AMA
One of the challenges that prevent local farmers from realising their full potential is post-harvest losses. These losses emanate from limited storage options that leads to farmers selling their produce prematurely.
As such, development of cold and dry storage facilities has become critical to enable especially smallholder farmers to contribute more meaningfully to the economy.
But what are
post-harvest losses?
Post-harvest losses mean a measurable quantitative and qualitative loss in each product. These losses can occur during any of the various phases of the post-harvest system. Post-harvest loss includes food across the supply chain from harvesting of crop until its consumption. The magnitude of post-harvest losses in the food supply chain varies greatly among different crops, areas and economies.
There are several types of post-harvest losses which include, losses in weight and quality, losses due to change in germinative properties, losses due to change in food qualities, losses due to physical condition and economic losses.
Further, there are internal and external causes of post-harvest losses. Internal factors occur at all stages in the food supply chain from the moment of harvesting, to handling, storage, processing, and marketing.
The primary cause of losses at the harvest stage include the absence of an established maturity index for some commodities, and/or lack of maturity index for local export markets.
In addition, low adoption of established indices, as price and distance to market influence adoption. Poor weather at harvesting time can also affect the operations and functionality of harvesting machines or human labour and usually increases the moisture content of the harvested products.
Pre-cooling loss
This is primarily due to the high cost and lack of availability of pre-cooling facilities, inadequate training on pre-cooling technology at the commercial scale, and lack of information on cost benefits of pre-cooling technology.
Transportation
Challenges in the transportation stage of the supply chain include poor infrastructure, lack of appropriate transport systems, and a lack of refrigerated transport. In most developing countries, roads are not adequate for proper transport of horticultural crops.
Also, transport vehicles and other modes of transport, especially those suitable for perishable crops, are not widely available. This is true both for local marketing and export to other countries. Most producers have small holdings and cannot afford to purchase their transport vehicles.
Storage
The storage facilities, hygiene, and monitoring must all be adequate for effective, long‐term storage. In closed structures (granaries, warehouses, hermetic bins, silos), control of cleanliness, temperature, and humidity is particularly important.
It is important to manage pests and diseases since damage caused by pests (insects, rodents) and moulds can lead to deterioration of facilities (e.g. mites in wooden posts) and result in losses in quality and food value as well as quantity.
Grading
Proper packing and packaging technologies are critical to minimise mechanical injury during the transit of produce from rural to urban areas. Causes of PHL in the grading stages are lack of national standards and poor enforcement of standards, lack of skill, awareness, and financial resources.
Packaging and labelling
After harvest, fresh fruits and vegetables are generally transported from the farm to either a packing house or distribution centre. Farmers sell their produce in fresh markets or in wholesale markets.
At the retail level, fresh produce is sold in an unpackaged form or is tied in bundles. This type of market handling of fresh produce greatly reduces its shelf life if it is not sold quickly.
Secondary processing
Causes of post-harvest loss in this stage include limited availability of suitable varieties for processing, lack of appropriate processing technologies, inadequate commercialization of new technologies and lack of basic infrastructure, inadequate facilities and infrastructure, and insufficient promotion of processed products.
Biological
Biological causes of deterioration include respiration rate, ethylene production and action, rates of compositional changes (associated with colour, texture, flavour, and nutritive value), mechanical injuries, water stress, sprouting and rooting, physiological disorders, and pathological breakdown.
The rate of biological deterioration depends on several environmental factors, including temperature, relative humidity, air velocity, and atmospheric composition (concentration of oxygen, carbon dioxide, and ethylene), and sanitation procedures.
Microbiological
Micro-organisms cause damage to stored foods (e.g., fungi and bacteria). Usually, microorganisms affect directly small amount of the food but they damage the food to the point that it becomes unacceptable. Toxic substances elaborated by moulds (known as mycotoxins) cause loss in food quality and nutritional value.
External factors
Factors outside of the food supply chain can cause significant post-harvest loss. These factors can be grouped into two primary categories environmental factors and socio-economic patterns and trends. Environmental factor being climatic conditions, including wind, humidity, rainfall, a
Building aggregation units and improving road infrastructure
Under the National Horticulture Recovery and Growth Plan, the Agricultural Marketing Authority is expected to embark on domestic and export market development for horticultural commodities.
One of the activities to be employed is the establishment of aggregation centres across the country. The Aggregation Centres will act as agricultural produce collection centres for bulking, sorting storing for store the commodities for onward marketing and distribution.
Improving infrastructure such as roads is critical in reducing post-harvest losses. Horticultural crops such tomatoes can benefit greatly from reduced transit time in market linkage and better travel conditions.
The current thrust by the Government to modernise the road network in the country will reduce travel time to the marketplace by smallholder farmers whose farming enterprise are usually located in the remote parts of the country.
◆ Word from the market is a column produced by the Agricultural Marketing Authority (AMA). Feedback [email protected] or [email protected]
