“Rajnigandha”- Freshness preserved

It is believed that tuberose was brought to India via Europe in 16th Tuberose (Polianthes tuberosa Linn.) commonly known as ‘Rajnigandha’ is a bulbous summer flowering perennial ornamental plant which belongs to the family Amaryllidaceae. It is considered to have originated in Mexico.

The flowers have a funnel-shaped perianth, waxy white about 25 mm long, single or double, and borne in spike.  ‘Single’ varieties are more fragrant than ‘Double’ types. The terminal flower spikes arising from the bulb produce flowers for a number of days. Fruit is a capsule. Tuberose inflorescence (spike) bear 10-20 pairs of florets that open acropetally. Commercially, spikes 60-90 cm long are harvested when two or three basal florets are open. The tuberose is grown on a wide range of soil and climatic conditions but it thrives and flowers best in warm and humid climates.

The temperature above 40° C reduced the size of the spike and the quality of flowers. Very low temperature and frost also damage the plants and flowers. The optimum temperate range is 20° C to 30° C . Tuberose is one of the potentially valuable cut flowers and is an important commercial flower crop of our country. The vase life of cut flowers with its keeping quality is most important and economic for tuberose growing farmers. It has been established that the post-harvest behavior of flowers is an outcome of the physiological processes occurring in the leaves, stem, flower bud, the leafless peduncle connecting the bud to the stem. Mineral nutrition, foliar feeding, irrigation, and growth regulator sprays were found to influence the longevity and post-harvest quality of cut flowers.

Improvement of the keeping quality and enhancement of vase life of cut flowers is an important area of floricultural research. Although various methods have been developed to extend the vase life, however, there is a need to develop a simple technique, which may be followed right at the grower’s end. Adoption of proper post harvest treatments in cut flower is important to achieve good exportable quality. Post harvest management and value addition can increase prices of cut flowers up to 9-10 times. Packaging plays an important role in extending freshness, value addition and reducing damage. Presently,

the cultivators have no standardized post-harvest technology for post-harvest handling of cut flowers like a seasonal variation to vase life, use of floral preservatives, some harvesting operations like the proper length of cut flower stem and stage of harvesting, treatment of pulsing chemicals, pre-cooling treatments, packaging methods, use of wrapping materials, packaging boxes, etc. So it is a great need for the farmers and flower traders to standardize the protocol for post-harvest techniques for the tuberose cut flower spike.

The keeping quality and vase tuberose is one of the potentially valuable cut flowers and is an important commercial flower crop of our country. The vase life of cut flowers with its keeping quality is most important and economic for tuberose growing farmers, etc.

The best quality of the spike is very important from a marketing point of view in domestic as well as export, so there is a proper packing of cut flowers is an important factor that plays an important role for deciding the quality and vase life of the cut spikes. Presently, our cultivators are not aware of standard post-harvest technology including packing methods and materials for extending the vase life. So it is a great need to standardize the packing methods.

Thus, standardization and evaluation of proper technique of packaging and storage of tuberose are vital for the development of market strategy and accessibility at the international market for enhancing export potential. Storage of flowers at optimum stage and quality is important for high market value. Flower quality tends to decrease after dry storage of cut flowers.

Research conducted by the author lead to the conclusion that the role of packaging materials is vital for the vase life, quality parameters, and biochemical parameters of tuberose. In the present study, the treatment T1 (LDPE 100 gauge) showed the best result in terms of change in weight on 3rd day and at senescence, water uptake on 3rd day, vase life of cut spike, number of florets open at a time, percentage of open florets, however T2 (LDPE 200 gauge) was found superior with respect of opening of fifth floret (day), withering of 5th floret (day), dry weight of cut spike at senescence, percentage of partial open florets and T3 (Radium paper) recorded, change in weight on 6th day, water uptake on 6th day and at senescence. While the T5 (Brown paper) was found to be best in terms of the percentage of unopened florets, change in reducing sugars. T7 (Control) was found to be best in terms of change in total sugars and change in non-reducing sugars.

The result may be due to a modified atmosphere, which increased the CO2 concentration as well as humidity and slow down the transpiration inside the package leading to a slow in the respiration process. Furthermore, it might have higher turgidity and freshness, contains more amount of carbohydrates and energy because of the reduced permeability of polyethylene sheet. The polyethylene reduced the permeability to moisture and air, thereby reducing the weight loss probably due to a reduction in the moisture loss, respiration, and cell division processes.

Thus, the water balance in the spike was increased. Higher water balance is associated with gain in fresh weight and it seems to be the most important aspect in the extension of the longevity of cut flower.