There are two main functions of post-harvest management:
1. To maintain the good quality of the harvested produce for the market.
2. To reduce the level of losses in weight and quality after harvest so that the shelf/storage life of the produce is extended.
Estimates of post-harvest losses from the field to the market in the following types of produce are as follows:
Leafy vegetables - 50%
Green peas/beans - 30-50%
Fruits - 20-40%
Root crops - 10-20%
Dried products - 5-10%
The level of loss is related to the part of the plant the product represents and therefore, its life- sustaining (physiological) functions that continue after harvest.
Causes of Post Harvest Losses
The golden rule of post-harvest management is: "QUALITY CANNOT BE IMPROVED AFTER HARVEST BUT MAINTAINED"
Therefore, only good quality produce must be prepared for market.
Poor quality produce will have a short post-harvest life.
However, the quality, condition and the ability to market fresh produce can be greatly improved by the farmer carrying out proper cultural practices.
Proper post-harvest management practices
Produce must be harvested without any form of damage and under certain conditions in order to maintain its good quality and prevent spoilage.
Factors to consider:
a) Maturity of the produce
This speaks to the ideal condition for consumption.
Features used to judge the best quality produce include: shape, colour, texture, smell and resonance (sound when tapped); widening of segments (breadfruits, soursop); and drying of the aerial part of the plant (yam, dasheen, onion). Immature produce has a short post-harvest life.
b) Time of day to reap
c) Harvesting tools and methods
The use of proper tools will prevent unnecessary injury to the produce being harvested.
It is recommended by the Rural Agriculture Development Authority (RADA) that the use of picking poles with bag be employed or climbing and picking by hand to prevent fruits from falling to the ground.
Use of short, sharp knives for cutting stems and trimming in the field is recommended. Outer protective leaves of some types should be left to protect the product through to market.
Root tubers and bulbs
These can be pulled out of the ground if the soil is loose, digging sticks may be used to remove the soil, or a fork being placed far from the root to loosen the soil and lever the tuber up out of the soil.
d) Field handling
Selection and grading:
Farm produce are packaged for four main reasons:
However, the type of packaging used can account for 15 to 20 per cent of post harvest loss in fresh produce.
Read more post-harvest management techniques in the next edition of The Agro Gleaner.
Further information can be had from the Rural Agricultural Development Authority (RADA) by calling 1-888-ASK-RADA or by logging on to www.rada.gov.jm.
Information for the RADA Diaries is compiled and provided by the RADA Communication and Public Relations Department.