MSc

Investigations on developing technology for production of dry flowers
were carried out during 2001-2003 at the Department of Pomology and Floriculture,
College of Horticulture, Kerala Agricultural University, Vellanikkara. The objectives
were to assess the suitability of selected commercial flowers, namely, celosia, china
aster and gerbera for dry flower production and to develop techniques to dry, bleach
and dye flowers for commercial exploitation.
Four stages of harvest, namely, tight bud, half bloom, full bloom and over
bloom stage Were assessed under each flower to standardise the optimum stage at
which drying was perfect to retain, colour, shape and visual quality at its best. Full
bloom stage recorded highest cumulative score for all visual and aesthetic qualities,
closely followed by half bloom stage in all the three flowers.
Celosia and aster flowers took 2 days and 5 days, respectively, for shade
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drying and proved to be cost effective with maximum cumulative score for visual and
aesthetic qualities. This was followed by microwave oven drying and hot air oven
drying.
The time taken for perfect drying of gerbera varied from 6 minutes
(microwave oven drying) to 4 days (shade drying). Among the drying methods,
highest cumulative score was recorded in microwave oven drying, followed by hot air
oven drying and shade drying.
Among the desiccants, aster and gerbera flowers embedded in fine clean
white sand recorded maximum cumulative score for all quality parameters, viz.,
brightness, brittleness and colour fading when dried in shade/microwave oven. The
flowers retained colour and shape on drying. The dried flowers retained only the
colour in borax and had a dull appearance when silica gel powder was used.

Celosia flowers immersed in hydrogen peroxide 30 per cent solution for 6
hours was found to be the best bleaching chemical and recorded maximum score for
aesthetic and visual qualities. Sodium hypochlorite (15 %) took 14 hours for effective
bleaching and recorded as the second best bleaching agent. Calcium hypochlorite
recorded low visual and aesthetic qualities for bleached celosia flowers. Hypochlorite
bleaching resulted in cellulose damage and yellowing.
Vat colour group of dyes was found good for celosia. Under the Vat group,
Basic Rhodamine, Methylene Blue and Auromine Yellow were suitable. Dyes at 0.2
and 0.3 per cent concentration gave high score for visual aesthetic qualities.
Immersion of celosia flowers in dye solution for 10 and 15 minutes recorded similar
visual qualities.
Colour fading on storage was mimmum in Vat colour group and fast
among Base group. The dyed celosia flowers had to be stored in dry cardboard boxes
sprinkled with silica gel crystals at the bottom. Lining materials reduced, the level of
colour fading on storage in celosia flowers dyed with pro cion colours. Level of colour
fading on storage was highin dehydrated aster flowers. Gerbera recorded low colour
fading on storage when packed in air tight containers after sprinkling silica gel crystals
at the bottom.
The floral crafts prepared can be made cost effective by using locally
available materials and increasing the volume of production. Along with dry flower
industry, there is ample scope for development of a number of subsidiary industries
like preparation of baskets, paper, ribbon, metal and packaging for dry flowers and
floral crafts. Thus this industry as a whole can contribute immensely to area
development which in turn lead to the overall development of the nation.