Post harvest managements

In agriculture, post harvest handling is the stage of crop production immediately following harvest, including cooling, cleaning, sorting and packing. Post-harvest treatment largely determines final quality, whether a crop is sold for fresh consumption, or used as an ingredient in a processed food product.

The most important goals of post-harvest handling are to keep the product cool, to avoid moisture loss and slow down undesirable chemical changes, and avoiding physical damage such as bruising.

Initial post-harvest storage conditions are critical to maintain quality. Each crop has an optimum range for storage temperature and humidity. Also, certain crops cannot be effectively stored together, as unwanted chemical interactions can result. Various methods of high-speed cooling, and sophisticated refrigerated and atmosphere-controlled environments, are employed to prolong freshness, particularly in large-scale operations.Â

Vase Life of cut flowers:

A fresh flower is still a living specimen even though it has been cut from the plant. The vase life of cut flowers decline due to the following reasons.

• Inability of stems to absorb water due to blockage
• Excessive water loss from the cut flower
• A short supply of carbohydrate to support respiration
• Diseases
• Ethylene gas
• Room temperature and humidity

Preservatives are used to extend the vase life of cut flowers. Floral preservatives are very effective in maintaining quality and extending longevity. We can have almost double vase life by using preservatives in water as compared with no preservatives.

Floral preservatives perform three functions:

• Provide sugar (carbohydrate).
• Supply a bactericide to prevent microbial growth and blockage of the water- conductive cells in the stem.
• Acidify the solution

Some of the preservatives used in floriculture are:

• Aluminium Sulphate (Also₄)
• T.S. (Silver Thio Sulphate) Solution
• Chlorine
• Rvb Chrysal
• Florissant

Water should be treated with any of the above mentioned preservatives and then flowers should be put into the bucket.

• Rvb Chrysal preservative is used @ 2 ml/liter. Every bucket containing 5 to 7 liters water. We should add 10 to 15 ml of Rvb Chrysal.
• Florissant buffer stock solution of 8 liters is prepared by adding 1 liter of Florissant and 7 liter water. Later added to every bucket containing 5 to 7 liter water. Florissant is available in a convenient pack of 1 litre, 5 litres, 10 litres, 25 litres and 200 litres.
• Chlorine it is added 20 mg/liter.

Vase life testing Procedure:

Testing vase life of flowers is nothing but checking the life of harvested flowers from the day of harvest to the final drooping after full open. Following steps are to be followed.

• Take two containers or glass bottles named containers A and container B.
• Container A container pure water with EC < 0.5 and pH > 5.5 to 7.
• Container B contains water and preservative in desired quality.
• The quantity of water should be half of the container size. Generally the height of the container should be 30 to 40 cm and diameter around 10 to 15 cm.
• Select two stems of same length, bud size, bud opening of the same variety. Cut the bottom of the stem 1 cm and keep in the containers.
• Keep the stems in containers.
• Everyday cut the bottom of the stems by 4 cm and keep it again in the same container.
• Every alternate day replace water and water with preservative.
• The experiment should be carried out at room temperature and normal humidity with enough light.
• Continue the procedure till both the stems are fully open and get dropped.
• Count the number of days since the start of experiment and that is the vase life of the flowers. Such experiment should be carried out for different varieties in different seasons.