Cut plants, bedding plants, foliage potted plants and bulbous plants are produced in big cities like Lahore, Karachi, Islamabad, Rawalpindi, Multan, Faisalabad, Nawabshah, and Hyderabad. According to estimates, 50-52 tons of fresh flowers are produced daily (20,000 tons per year).

Postharvest handling plays an important role in maintaining the quality of flowers. In Pakistan, 20-30% losses of cut flowers are due to poor postharvest handling. Cut flowers are highly perishable products and the most deteriorating factor for them is temperature. For cut flower crops, cold storage is required for marketing flowers to distant markets, hundreds or thousands of miles away from their site of production.

Currently, harvesting is done by hand using a sharp knife and shears. Harvested flowers are placed in buckets. Sorting and grading is very important. Flower size, bud diameter, stem length, vase life, maturity, uniformity and foliage quality are the factors that are used during the grading of cut flowers.

Flowers like cut roses, orchids and other specialty flowers are normally bunched for local trade and export. The number of flowers in bunches varies according to growing area, market and flower species. Groups of 10, 20, 25, 50 and 100 are commonly used for single stemmed flowers. Spray type flowers are bunched by number of open flowers. Bunches are held together by string or elastic bands. Flowers are graded and bunched before being treated with chemicals or placed in storage.

Various chemical solutions are used after harvest to improve the quality of cut flowers. Pulsing is immediately done after harvesting to extend the storage and vase life of flowers. Ethylene sensitive flowers are pulsed with silver thiosulphate, while close bud flowers are placed in bud-opening solutions. The solutions contain sugar and germicide. Foliage of some flowers is damaged if sugar concentration is very high.

There are many shapes of packing containers for cut flowers but most are long and flat. Newspaper layers are often used to protect the layer from injury. It allows for more cooling of flowers after packing. Then the flowers are placed in a wooden box or cardboard carton. For wet storage, the cut stem ends are kept in water or flower preservative. Acids or acid salts are also added to adjust the pH of the water to 3.5 to 5.0. For dry-pack storage, flowers are sealed inside plastic bags.

Ultimately, the handling area and cold storage should be cleaned and sanitized after each use. Equipment, cutting tools, containers and handling surfaces should be cleaned and disinfected with a 1:10 bleach solution. Unmarketable flowers should be disposed of after each harvest. Dying plant material is a reservoir for plant disease organisms and produces ethylene. All shorten the storage and vase life of flowers.

Source: Department of Horticulture, University college of Agriculture, University of Sargodha; Mehwish Siddique, Dr. Gulzar Akhtar, Dr. Ahsan Akram, Dr. Rashad Mukhtar Balal