Floriculture has assumed a definite commercial status in recent times. The commercial activity of production and marketing of floriculture products is also a source of gainful and quality employment to scores of people. The social and economic aspects of flower growing were, however, recognized much later. The offering and exchange of flowers on all social occasions, in places of worship and their use for adornment of hair by women and for home decoration have become an integral part of human living with changing life styles and increased urban affluence. Rose is the most important cut flower and ornamental bedding plant in a garden. It is the number one cut flower in the international market. For cut flowers roses are extensively cultivated in Netherlands, Columbia, Japan, France, United States of America (USA), Morocco, Korea and Israel. In flower market mainly Hybrid Tea (H.T) and Floribunda Types are in demand for production of cut roses. In India, it is grown under green house for cut flower purpose and large number of varieties are grown for garden purpose.
Roses can be grown successfully under various climatic conditions. Quality flowers are obtained in areas with bright sunny days, cool nights, moderate humidity and absence of strong winds. In general, it preferres day temperature of 25 to 300 C and night temperature 15 to 160 C. Long days of 12 hours and humidity of 60 to 70% favours growth and quality flower production. During flower bud initiation, long days play an important role but later stage of bud development is influenced by light intensities. Additional light and temperature promote, early flowering under protected conditions.
Selection of Site
Selection of site is very important for successful growing of roses. The selected site for rose planting should get full day sunlight. In summer season it prefers partial shade during the hot afternoons. In the garden rose plantation area should not be too close to tall trees. It do not prefers water logging conditions even for a short period. The location of rose plantation should be free from dusts.
Soil and Preparation
Rose plants grow well in medium loamy rich in organic matter, well drained soil of at least 40 to 50 cm depth. The sub-soil must have the capacity to hold and retain adequate moisture. Clayey soils which are heavy and poor in aeration are not preferred by rose plant. In case of clay soil, it is advised to mix sand and well decomposed FYM to make it porous. The best soil pH for roses should be 5.5-6.5 with electrical conductivity less than 1. Now-a-days, artificial media like cocopeat, perlite and mixture of cocopeat and perlite are preferred because they are inert, sterile and have no cation exchange capacity, so that applied nutrients are available to the rose plants directly. Roses fall into the sensitive category of plants with respects to salinity tolerance. Budded plants have less tolerance to adverse conditions of soil and climate than plants raised from cuttings.
Roses are perennial plants and will remain in the same bed for many years. The initial preparation of the soil should preferably start during summer season. Before bed preparation mix the basal dozes of fully decomposed dry FYM @ 6-8 kg/ sqm. and quantity of inorganic fertilizer is depending on fertility of soil. In termite prone areas, antitermite chemicals like chlorpyriphos should be applied to the soil before planting. Rectangular 30 cm raised beds with 40-50 cm wide path between two beds offer certain advantage for cultural operations. The width of bed should be 1.0 m and length of bed should be depending on dimension of polyhouse. In the rectangular bed, planting two rows will be a good practice. Average plant population vary from 7 to 9 plants per sq.m.
Rose is propagated by seeds, budding, grafting, layering, cuttings; and through micro-propagation for disease free plants. Asexual propagation allows plants to grow true to type. It is commercially propagated by vegetative method like budding.
i. Stem Cuttings
Rose root-stocks are generally propagated from matured stem cuttings. This is the cheapest method of propagation of roses. This method is particularly adopted for multiplying Miniature, Polyantha, Climber and Rambler roses. It is also useful in multiplication of Rosa multiflora, R. bourboniana, R. moschata,R. canina and R. indica var. Odrata as root-stocks. . Usually one year old shoots from healthy plants are used as cuttings. Rooting of cuttings varies with the type of cutting, season when cutting are taken, growing media, moisture conditions, species and growth regulator treatment. The cutting may have one, two or more buds. The technique of raising plants from cuttings of matured shoots, in hilly region is as follows. During winter months, from September to November, one year old shoot from healthy plant is cut from the base. From this, several pieces measuring about 20 to 22 cm long each are clean cut just below the node with sharp secateur and lower leaves are removed. The cuttings are generally planted 5-6 cm deep, keeping the distance between cuttings 8-10 cm and between rows 12-15 cm in sand or cocopeat or mixture of cocopeat and perlite (1:1 ratio) under partial shade conditions with regular watering. After 12-15 weeks, sufficient roots are formed oin the cuttings and they can be transplanted in the field or poly bags.
In this method of propagation, detached bud from a selected rose variety is inserted into selected root-stock. T-budding is the most widely accepted method for propagating ornamental rose plants. The cambium layer is the growing layer, which is found between the wood and the bark of the shoot. Success of budding mainly depends upon joining the cambiums of the root-stock and that of the bud. The performance of the budded variety depends much on the root-stock in terms of vigour and production of quantity and quality of flowers. It is necessary to choose the most suitable species of root-stocks. In northern India,Rosa indica var. Odorata and R. multiflora in central part of India & Rosa damascene in southern India have been found highly promising and extensively used rose root-stocks. The best time for budding in north India is during February to March, in eastern India during October to November and February to March; in the hills, budding may be done in spring season.
Stenting is a method for quick propagation of roses. A piece of stem of the cultivar with one dormant bud is grafted on a root-stock. In stenting bud/graft union formation and of adventitious roots occur simultaneously, resulting in a complete plant in 2-3 months.
Rose plants revel in low temperature and root growth is very active in winter season. Its plants can be planted at any time of the year. However, irrespective of the locations in hills, October is the most suitable time for planting of roses. In temperate climate, it can be planted in open field from October-November and February to March. Rose plats are best planted in rows. To get maximum flowering shoots, roses should preferably be planted a spacing of 20-25 cm from plant to plant and 50 cm row to row within beds may be required for Hybrid Teas and Floribunda. Roses should be planted on thoroughly prepared pits in beds. Before operation of planting, this should be ensured that the soil just moist in beds. The depth of planting will vary with the type of planting materials. The budded plants are planted in such a way that the budding/matrix point should remain 5-7 cm above the soil surface.
Roses are very fond of water and require one to two inches of it every week. During hot, dry season, even more may be needed depending on the size of the bushes. In spite of their need for abundance of water, roses hate standing in water and provision for proper drainage is essential. Irrigation should be done during the morning time. Avoid evening watering, which could foster powdery mildew which is a very common disease among roses. During the rainy season, watering will be required only during the dry periods.
Pruning is one of the most important operations in rose cultivation which influences the yield and quality of flowers. In pruning all dry, diseased, weak and crisscross shoots are removed to open up the center of the bush. Any suckers that arise from the root-stocks are also removed. The best time of pruning is during the period when the rose plant is at dormant to near dormant stage. It will depend on the climatic conditions of the rose growing region. Usually the Hybrid Tea and Floribunda roses take 45-50 days to come to flowering after the pruning. In, plains pruning is recommended in 15 October to 15 November. In hilly areas where the winter is very cold, the pruning operation is done in last week of February to 15 March.
Rose is heavy feeder crop & it require regular feeding of nitrogen, phosphorus, and potassium are required large quantities. When nitrogen is deficient, the young leaves become small in size, develop pale green colour with yellow and red tints and the buds develop poorly and are light in colour. In North India, a high nitrogen dose is more effective for increasing stem length, flower yield and quality of flowers of cultivar Super Star. Phosphorus is important for encouraging root growth and stimulating flowering. It can be applied in the form of super phosphate and phosphoric acid. Its deficiency symptoms in rose are blue green or dark green leaves, weak stems and slow bud development due to poor roots. Potassium is responsible for hardiness of flower stem, better quality of bloom and increased resistance to diseases. Due to potassium deficiency lower leaves show browning, stem becomes weak and colour of flower gets poorer.
In manual fertilizer application nitrogen in combination with phosphorus and potassium 9g N + 8g P2O5 + 8g K2O per m2 per week are recommended for flower yield and quality.
Foliar spray of micronutrients is more effective in roses. It is recommended that 3 g each of magnesium sulphate and potassium sulphate along with 0.75 g borax dissolved in 1 liter of water and sprayed on rose corrected the deficiency of magnesium, potassium and boron.
Weeding and Hoeing
Weeding if neglected, may cause a setback in flower yield and quality. Manual weeding is the most prevalent practice. Hoeing of rose beds at fortnightly intervals is helpful in removing weeds and loosening soil for better aeration and improving soil moisture retention capacity. Shallow hoeing is preferred as deep hoeing destroys the fibrous roots.
Mulching reduces weed infestation and promotes economy of irrigation water. Various materials such as dry plant leaves and paddy straw etc can be used for mulching. About 6-8 cm mulch of dried leaves of Jamun tree in rose beds in the month of April does not allow any weeds for about 2 months i.e. in May and June and reduces their reappearance in following months.
Removal of a part of terminal growing region of shoot is known as pinching and is an important operation in rose cultivation, after every flush, minor pinching is done for the succeeding return crop and for adjust flowering for a specific timing. Pinching reduces the plant height and increases new axillary branching. It should be carried out above 3 leaflets in weak and 5 leaflets in healthy shoots.
Disbudding and Disuckering
Disbudding of axillaries buds in Hybrid Tea and Floribunda roses are beneficial for increasing the size of flower. The suckers appearing from root-stocks should be removed periodically from the point of origin.
Insects and Pests
Red spider mite (Tetranychus urticae)
Mites are very common on rose. They first appear on lower surface of leaves, and can subsequently cover the entire leaf, stem and after sometime whole plant with their web. The infected plants give dusty and webbed appearance. These can be controlled by spraying Kelthane @ 0.1% or Omite 0.03%.
Caterpillars are mostly a problem of rose buds and young leaves. In the initial stages, they eat away the foliage. The eggs are laid on the buds and larvae eat into the bud damaging it completely. Caterpillars can be controlled by spraying Nuvan @ 0.15 to 0.2%.
Aphids (Macrosiphum rose and Aphis gossypii)
Aphids occur in more than 4000 aphis species. Many are vectors for a number of viruses. Aphids are sucking insects that draw chlorophyll from leaves and buds. It is recommended to spray of Metasystox or Malathion @ 0.2 % to control aphids.
Thrips (Thrips maginis and Frankliniella tritici)
Among insects, thrips are the most serious pests on rose. Thrips prefer dry hot conditions. Both nymphs and adult forms of this small insect and suck the cell sap from the leaves, tender stem and flowers. It is recommended the application of dimethoate and monocrotophos @ 0.05-0.1% to control thrips.
Red Scale (Lindingaspis rossi and Aonidiella aurantii)
Red scale insect attacks on the lower part of old stem of rose and cover them with reddish brown waxy incrustation. The scale insect sucks the plant sap and the infested stems gradually dries up. Rainy season is the main period for infestation of red scale insects on rose plant. These insects can be removed by rubbing the infested stems with old soft tooth brush. These can be controlled by spraying Monocrotophos @0.1-0.15%.
Dieback (Diplodia rosarum)
Fungi such as Colletotrichum sp. have also been found associated with die back disease. The severity of this disease is noticed after the pruning operation. As sit name indicates, symptoms of this disease are blackening at the tip of stem which spreads downwards rapidly. The disease can be prevented by taking precaution at the time of pruning. The pruning cut should be slanting and made with sharp secateurs. Some systemic fungicides like Bavistin 0.2% should be sprayed immediate after pruning. Removal of affected part including about 2-3 cm below in the healthy part and use of Bavistin paste afterwards controls the disease.
Powdery mildew (Sphaerotheca pannosa var. rosae)
In powdery mildew, initialy whitish tiny spots appear on young leaves. The entire plant displys white powdery appearance in severe cases, consequently reducing the vigour of the plant. Infected buds do not open and in open flowers the infection leads to discolouration. The disease can be controlled by Karathane (0.1%) or Benlate (0.1%) sprays.
Downy mildew (Peronospora spersa)
Downy Mildew is a very common disease of roses and occurs under moist cloudy conditions. All species of cultivated and wild rose seem to be susceptible. Under cool and moist spring conditions, young leaves, stems and flowers may manifest purple to red or brown irregular spots. As the disease advances, lesions on leaves become angular and black with the possible appearance of white mycelium on the underside of the leaf. The disease can be controlled by spraying Ridomil or Dithane M-45 0.2%.
Black spot (Diplocarpon rosae)
This fungal disease was first reported in 1963 and causes major problems in cold climate of temperate region and during rainy season in the plain area. The infested leaves show black spots on upper and lower sides. At later stages, leaves become yellow and fall off. The disease can be controlled by spraying Dithane M-45 0.15%. It is also advised to have minor pruning if required during rainy season if there is over growth including removal of minor and diseased shoots.
Flower harvesting and post harvest management
The flowers are harvested when they are at tight bud stage and when petals have just started unfolding. It should be harvested either in the morning or evening by sharp secateur. After harvesting, flowers should be dipped in clean water. To store cut flowers, it is recommended to place them in good quality water at 2-40C temperature. Approximately in Hybrid Tea and Floribunda roses 150-250 and 250-300 flowering shoots/sqm/year respectively a reasonable expectation for polyhouse grown roses.