Jasmine: Genetics and Modification | Flowers

After reading this article you will learn about:- 1. Origin, Species and Varietal Wealth 2. Jasmine Oil and Concrete 3. Diseases.

Whenever, we think of fragrance, flowers like rose, jasmine and tube rose are immediately come to our mind and sweet smell of these flowers start filling in our nostrils and give a magical relief to mind and provide solace. Though there are many more other fragrant flowers but these three flowers are top ranking in area and production either for loose, cut flowers or for extraction of oil.

Amongst these, jasmine is a very important group of plants which is cultivated extensively in tropical and sub-tropical areas of Southeast Asia and other parts of world for garden decoration and commercial purposes.

The white and fragrant flowers of Jasmine are symbol of purity, eternal love, nobility and also symbolize the beauty of girl. It is offered to the God and used for worshiping and hence, these are preferably planted in Hindu temple gardens and Mogul gardens.

The genus Jasminum belongs to family Oleaceae and is of about 200 species which are mainly shrubs and climbers. Mostly, the plants of jasminum species are ever green but winter deciduous species viz. Jasminum nudiflorum is also found. Leaves are dark green in colour, opposite, and varying from simple (J. sambac) to tri foliate or pinnate with up to 9 leaflets (J. grandiflorum, J. Officinale, J. multiformum, etc.).

Flowers are waxy white in most of the species but yellow colour is also found in J. humile, J. nudiflorum, and J. mesnyi. Similarly, there is a quite variation in flowering time. Earliest flowers are produced during spring only in J. humile whereas in most of the species flowers are produced in spring through summer with peak flowering in rainy season till autumn. Some species also produce flower during winter season i.e. J. multiflorum, J. nudiflorum and J. mesnyi.

Most common species are: J. sambac, J. grandiflorum, J. auriculatum, J. humile, J. multiflorum, J. officinale, J. nudiflorum, J. mesnyi, J. angulare, J. angustifolium, J. nitidum, J. parkeri, J. polyanthum, J. pubescens, J. rex, etc. Jasmines are widely cultivated for their flowers which are used for making veni.

Jasmines are native to tropical and warm, temperate regions of south East Asia, west Asia, and Europe. Jasminum sambac is the national flower of Philippines which was adopted in 1937. It is also national flower of Indonesia which has been adopted recently in 1990 by Indonesian Government along with Moon orchid (Phalaenopsis amabilis) and Rafflesia arnoldii.

Origin, Species and Varietal Wealth:

There are about 200 species which are widely distributed in the countries of Asian and European continents.

The important species are described hereby:

J. sambac:

It is national flower of Philippines and Indonesia and commonly called as Arabian Jasmine, or motia or mughra. It is evergreen, makes bushy growth and produces long scandent branches in growing season which starts from spring continue to summer and rainy season. It produces white fragrant flowers of varying degree of doubleness, single and semidobule and double flowers.

Flowers are mostly used in making garlands and for extracting perfume for cosmetic industry. Flowers of J. sambac are used for making green tea which is considered effective in preventing cancer when taken daily. Verities of J. sambac has been classified and described by Tamilnadu Agricultural University Coimbatore on the bases of number of whorl, length of pedicel, corolla tube length and shape of flower bud. The varieties Mandan ban, Gundumalli, Rambanam, have been considered better than other Verities in terms of yield of flowers and other characters.

J. grandiflorum:

It is commonly called as chameli or Spanish jasmine. It is ever green with dark green imperipinnate leaves producing long branches. Flowers of bigger size of pure white colour are produced from April to November and flowers are used in making veni, garland, bracelet, etc. and for extracting oil.

Six varieties of J. grandiflorum were selected at T.N.A.U., Coimbatore depending upon floral characters and ploidy level. Out of six, five are pink and one is of white colour. One of pink was triploid (39) and rest are diploid (26). The triploid are highly sterile. An improved variety ‘COI Pitchi’ with an average yield of flowers 10.15 tonnes/ ha and with recovery of 29.5 kg/ha of jasmine concrete has been released and has become very popular amongst growers in south India.

J. auriculatum:

It is commonly called as juhi. It is evergreen shrub and produces white and highly fragrant flowers. Flowers are sold in the market as loose flower for making veni, garland, bracelet, etc. and for extraction of essential oil.

Based on flower bud characteristics, at T.N.A.U. Coimbatore five variants were selected and named as long point, long round, medium point, short point, and short round. These clones exhibited variation in susceptibility to common gall mite pest, however, medium point was found to be highly resistance to the pest which was named as ‘Parimullai’. Latter on another selection of long round bud i.e. ‘Col Mullai was released which produced 8800 kg/ha of flowers with good market potential.

J. multiflorum syn. J. pubescenms:

It is commonly called as kund or dela in Punjab. It is ever green medium in height producing white flowers during winter months i.e. Dec.-Jan. Its bushy growth makes it highly suitable for planting in gardens and shrubbery border.

J. humile:

It is commonly called as pili-chameli on account of its yellow colour flowers. Leaves are dark green and makes luxuriant vegetative growth and hence, it is highly suitable for various situations in garden as ground cover, screening, against wall, or hiding unwanted sites. It produces semi double, deep yellow flowers in spring but for short duration i.e. 20-25 days.

J. mesnyi:

It is called as primrose Jasmine. It is ever green shrub with long slender arching branches. It grows about 1.5-3.0 m without any support. The bright yellow, semi double (6-10 petals), fragrant and trumpet shaped flowers are produced in spring and sporadically during summer. It is ideally suitable as a specimen or to trail over fences or walls.

J. nudiflorum:

It is commonly called as winter jasmine. It is winter hardy and produces yellow flowers in leafless condition during winter months.

J. polyanthum:

It is commonly called as pink jasmine on account of its pale pink fragrant flowers which are produced in cluster during summer months. It is evergreen, rapid grower and produce rich green foliage.

Climate:

For successful growing of jasmines, mild climate is required. Warm humid conditions favour for luxuriant growth, profuse flowering and high productivity of plants. The desirable temperature range is 15-30°C and beyond these, growth and flower production hampers. Ground frosts kill the shoots. Ample of sunny days are better for growth and flowering than cloudy day. Hence, the climatic conditions of South India are better than north conditions of India.

Soil:

Jasmines prefer well drained rich sandy loam to clay soil. Soil should be deep friable and free from calcareous soil. Jasmines are very well adapted to different kind of soils. It can tolerate wide range of pH . 

Propagation:

Jasmines are commonly propagated by cutting and layering but seeds are also used to create variations and new hybrids. There is large variation in seed germination due to species and clones. Diploid species exhibit better germination 75- 84% (J. grandiflorum and J. auricuatcum) whereas low seed germination of about 55% has been found in tetraploid species (J. flexile).

Cuttings:

Jasmines are easily propagated through different kind of shoot cuttings and percentage of rooting depends upon maturity of shoots in different species. In J. sambac both semi hardwood and terminal cuttings root better exhibiting 92 and 94 per cent, respectively whereas terminal cuttings in J. grandiflorum exhibits as high as 98% rooting.

In case of J. auriculatum, the semi hard wood cuttings and having terminal portion root better i.e. about 70%. Cutting made during summer months i.e., May to July roots better than January, April or October. Intermittent misting improves percentages of rooting as well as number and length of roots. Amongst rooting media coarse sand is better than other media. The number of days taken for rooting varies between 45 to 60 days.

Layering:

Layering is successful in Jasmines but being cumbersome it is not generally practiced. Grafting and budding has also been tried experimentally. Micro propagation by taking apical and axillary buds as explants have been standardized and can be used for multiplying large number of plants.

Planting in the field:

There are two main seasons of planting i.e., rainy and spring season. If water facilities are available and plants are prepared through layering, spring season should be preferred for planting on account of its long growing period. When plants are prepared through soft or hard wood cuttings planting can be done during rainy season i.e. after 15 August onward through September.

Plant spacing differs from species to species. To obtain the higher yield proper spacing should be followed. It has been observed that for J. grandiflorum proper spacing is 2 × 1.5 m accommodating 3333 plants/ha. Similarly, the proper distance for J. auriculatum was found to be 1.8 × 1.8 m and for J. sambac 1.2 × 1.2 m which is followed for commercial plantings.

At the time of planting proper care should be followed so that there is low rate of mortality. The size of pit varies from 45-90 cm³ depending on type of soil e.g. for sandy loam soil 45 cm³ size of pit is sufficient whereas for clayey soils the size of pit should be 90 cm³. After digging, the pit should be exposed to sun for at-least 7-10 days.

In each pit 10-20 kg of well rotten farm yard manure should be mixed and pit should be filled. It should be followed by soaking irrigation containing diluted solution of chloropyro phosphate to keep the termites under control and soil settles down. After a day or two, planting in the center of pit should be done in the evening and should be followed by light watering.

Nutrition:

For proper plant growth and flower production, jasmine plants need balanced nutrients. Since flowering continues for longer duration and, hence, regular supply of specially three major elements i.e. N, P and K is required. Any limitation of these nutrients will affect the flower production as well as quality of essential oil.

It has been reported from T.N.A.U., Coimbatore that in case of J. grandiflorum, the application of N, P and K @ 60, 120 and 120 g/plant, respectively along with 10 kg well rotten farm yard manure found to be optimum. It should be applied in two splits i.e. once in January and again in July every year.

For J. auriculatum, application of N at 120 g per plant and P and K at the 240 g/plant produced better flower yield. On the other hand, at Kalyani for J. sambac and J. auriculatum the response at N₅₀ P₂₅ K₂₅ g/plant was better. Thus, the response of N, P and K varies due to species and locality, soil types and soil fertility level.

Irrigation:

Jasmines require a regular supply of water during spring and summer season to maintain the luxuriant vegetative growth and for flower production. The scarcity of water during these months will hamper the growth and flowering drastically. Except the rains during these months normally deep irrigation is required once in a week, however, depending upon soil texture the frequency may be adjusted.

In sandy and sandy loam soils irrigation should be done at the interval of 3-4 days whereas for heavy textured soil, frequency of irrigation can be delayed to 10-15 days. During rainy season depending upon the intensity and frequency of rain fall, irrigation can be adjusted. During winter months i.e., from November to February irrigation can be done at the interval of 10-15 days.

Pruning:

In jasmines, flowering occurs on new shoots and hence, to get highest yield, the new growth should be encouraged by annual pruning or pinching of shoots. Pruning time and intensity ultimately affects the new growth of plants and flowering. It has been observed the pruning must be of much ahead of flowering.

Flowering can be regulated by manipulating the pruning time. In general, pruning is done in late winter months and it consists of removing all dead, dry branches and cutting back past season branches up to 45 cm from the ground level. Thus plants remain in easy reach so that plucking of flowers can be done easily.

In Jasminum sambac, it has been observed that pruning during December and January and up to 30 cm of ground level produced highest flower yield under South Indian condition whereas in North Indian conditions end of January is considered most ideal time of pruning.

On the contrary J. auriculatum and J. grandiflorum should be pruned in the end of January under both South and North Indian conditions. Chemical defoliants like para quatdichloride, penta chlorophenol, potassium chloride, sodium chloride or ethrel at higher concentrations has been reported useful in alternate to manual pruning but, however, they have not come in use on large scale. Still manual pruning is being practiced.

Flowering and Yield:

Flowering occurs during summer months through rainy season and till autumn. It has been observed that peak season of flowering occurs during long days associated with comparatively higher temperature during day and night both. Thus peak flowering occurs during June and July. The yield varies due to species and their cultivars.

In general yield is as follows:

Name of species – kg/ha

J. sambac – 739-8129

J. grandiflorum – 4329 to 10,144 (Pitchi)

J. auriculatum – 4733-9152

Jasmine Oil and Concrete:

Fragrance in jasmine flower is due to the presence of volatile oil present in inner and upper surface of both sepals and petals and oil glands are deep seated in the cells and hence, steam distillation is not able to extract oil. Thus, solvent method is used to extract the oil. The fragrance begins to develop in the flowers soon after sun set and ceases within a few hours of sun shine.

Therefore plucking of flowers is recommend early in the morning say up to 9.00 a.m. After this quantity and quality gets decreased. During transportation the factory care should be taken not to damage the flowers. The damaged flowers yield concrete with more percentage of wax.

The jasmine concrete is a wax like substance containing natural flower perfume as a volatile oil, plant waxes and colouring matter. Amongst various oil solvents like hexane, petroleum ether and carbon tetrachloride, out of these, food grade hexane was found better.

The boiling point of food grade hexane has been observed to be 60-80°C but even 70°C is highly satisfactory. This hexane has to be purified before using for extractions. For rotary type extractor 2 litres of hexane is found to be optimum whereas for static type it can be 4-5 litres.

The flowers are treated with purified hexane at 2 liter per kg of flowers for about 30 minutes. The complete extraction of the perfume from the flowers can also be ensured by slowly rotating the container having flowers and solvent for about 20 minutes in the rotary type of extractor.

After complete extraction of perfume, solvent is filtered and distilled at bout 70-75°C to recover the hexane. At this temperature, hexane evaporates leaving concentrated liquid which contain perfume and waxes and it is further purified by vacuum distillation for removing total amount of hexane. The final form of floral concrete is in the form of molten wax.

Floral concrete to recovery % in different species:

J. sambac – 0.14-0.19

J. auriculatum – 0.29-0.36

J. grandiflorum – 0.24-0.30

Insects, Pests and Diseases:

Mites:

Red spider-mites are very common in jasmines during warm and dry summer months. Severe puckering and discoloration of leaves are found due to crown gall mites in J. auriculatum. The cv Parimullai of J. auriculatum resistant to crown gall mites has been released from T.N.A.U. Coimbatore. To control mites, application of endrin @ 1 kg of 10% Wp./100 gal of water has been found useful than mat acid or parathion which were comparatively less effective.

Nematodes:

Jasminum sambac, J. flexile and J. nudiflorum are commonly attacked by root knot nematode (Meoidogyne incognita) which cause knot formation in roots, yellowing of leaves and die-back of shoots. Application of 8 kg Thimet/ha or 1 tonne neem cake/ha helps in checking the population of nematodes.

Diseases of Jasmine:

Wilt:

It is caused by Fusarium solani, J. sambac is very susceptible to the disease. In the beginning, yellowing of lower leaves start and slowly spread up and finally result in death of plants. In the field disease spreads in patches and roots show black coloration. The disease can be controlled by drenching the soil will 1% blitox.

Rust:

It is caused by Uromyces hobsoni and appears during rainy months i.e. July, August. It attacks severely J. auriculatum and other species like J. sambac, J. angustifolium, are also susceptible. This disease can be controlled by dusting sulphur @ 20-25 kg/ha or spraying with.

Leaf Blight:

It is caused by Alternaria jasmini and Cercospora jasminicola and results in formation of reddish brown circular spots measuring 2-8 mm which spread readily during rainy season. The disease appears in May-June and peak incidence occurs during rainy season.

Flower production is adversely affected and may cause 50% loss yield. J. grandiflorum is severely attacked by this disease and others show stray incidence. It can be controlled by spraying Blitox @ 2g/l or copper oxy-chloride (2 g/l). Mosaic viruses and phyllody caused by mycoplasma are also observed some time.