Marigold cultivation- A viable avenue for farmer's livelihood security
Authors: Kanwar Pal Singh, Prabhat Kumar, Sapna Panwar, Namita and Pavnesh K. Verma
Division of Floriculture and Landscaping, Indian Agricultural Research Institute
Among loose flowers, marigold (Tagetes sp. Linn.), is an important flower which is used for floral decorations, religious offerings and also for making garlands and flower baskets. It is native to South and Central America, especially Mexico. The species such as Tagetes erecta, Tagetes patula and Tagetes minuta are commonly cultivated in India. Today, it is one of the most important commercial flowers grown worldwide and in India it accounts for more than half of the nation's loose flower production.Major marigold growing states are Karnataka, Gujarat, Maharashtra, Haryana, Andhra Pradesh, Uttar Pradesh, Chattisgarh, Odisha, Jammu & Kashmir, Puducherry, Andaman Nicobar, Arunachal Pradesh, West Bengal, Tamil Nadu, etc. It occupies an area of 42,880 hectares with production of 3, 60,210 metric tons loose flower (NHB database, 2012-13). Marigold has gained popularity because of its adaptability to various soil and climatic conditions, longer blooming period, beautiful flowers which have good shelf life. Marigold flowers are mainly grown in India for loose flower production and being used extensively for making garlands, for beautification of mandaps and decoration of cars in marriages and religious offerings
Marigold flowers are rich source of carotenoids and being grown on commercial scale for extracting these carotenoids. Flower petals contain xanthophylls which are major carotenoids fractions and lutein forms 80-90 percent of the total xanthophyll content. Carotenoids are the major source of pigment for poultry feed used for intensification of colour of egg yolk and boiler skin. It has been reported that dietary carotenoids are the agents for prevention and treatment of several illness such as concerned photosensitivity diseases. The purified extract of marigold petals, containing lutein dipalmitate has been marked as an ophthalmologic agent under the name "Adaptional".They also protect the eye from long term damage by light which can lead to a progressive condition known as age related macular degeneration (AMD). Some of the carotenoids have been in the market for more than 20 years and are used extensively in food colouring. Marigold petals have anti-fungal, anti-bacterial and anti-inflammatory properties that can be utilized for the production of creams.Marigold species especially T. minuta oil is the most valuable and precious for using in high grade perfumes and cosmetics. Marigold leaves and flowers possess a good insect repelling properties It has juvenile hormonal and insect repellent activities against flies, ants and mosquitoes. Therefore, marigold oil is being used on commercial scale for formulation of insect repellent. Tagetes spp. have been reported by numerous researcher's to provide a method for protecting crop plants from damage caused by various nematode and insect pests .
Varieties from IARI
In marigold, many varieties and strains are available which vary in plant height, growth habit, flower shape and size. Mostly local varieties are being cultivated by the farmers which are generally low yielders. The Division of Floriculture and Landscaping, Indian Agricultural Research Institute, New Delhi has developed high yielding varieties of marigold which are as follows.
African marigold (Tagetes erecta)
Pusa Narangi Gainda: Pusa Narangi Gainda was developed by pedigree hybridization by crossing two exotic varieties Cracker Jack x Golden Jubilee. The plants of this variety are of medium stature, vigorous and uniform, foliage-dark green which grows to a height of 80-85 cm. It flowers in 125-136 days after sowing. The flowers are orange coloured, carnation type, double and compact in nature. The variety can yield upto 25-30 tonnes/ha and is commercially grown for loose flowers throughout the country during winter months.It is most suitable for garland making, religious offerings and carotenoid extraction.
Pusa Basanti Gainda: Pusa Basanti Gainda was developed by pedigree hybridization by crossing two exotic varieties Golden Yellow x Sun Giant.It is little late maturing variety which takes 135-145 days. The flowering duration is long (40-45 days), plants are 60 -65 cm tall, vigorous and uniform withdark green foliage. Flowers sulfur yellow coloured, carnation type, double and compact. It is ideal for loose flower production and also for growing in pots and beds in the garden.
French marigold (Tagetes patula)
Pusa Arpita : The variety produces tall, bushy and vigorous plants. Plant height and spread ranges from 90-100 cm and 60-70 cm, respectively. The foliage colour is dark green and stem colour is greenish purple. The crop establishment is very good and the plants grow straight with strong stems. The variety produces medium sized light orange coloured flowers. The flowers are compact with turmeric yellow colour of petals at lower surface.
Soil and Climate
Marigold can be cultivated in a wide variety of soils. A deep fertile, friable soil having good water holding capacity and aeration is suitable. Sandy loam soil with a pH of 7.0-7.5 having good drainage is favourable. Marigold needs plenty of sunshine, so it should be grown in open sunny conditions. In winter, seedlings and plants are damaged by severe frost so nursery should be sown under moderate conditions. The environmental conditions markedly influence the growth and flowering of marigold. Marigold is a quantitatively short day plant so flowering is accelerated by short days whereas long days may delay flowering when combined with higher temperatures. Mild temperature during growing period greatly improved flowering. The flowering of marigold can be taken throughout the year by taking crops in succession in order to ensure their regular supply to the market.
Marigold is propagated by both sexual and asexual propagation. However marigold is commercially propagated by seed. Plants raised from seeds are vigorous, healthy and establish well.It is also propagated by cuttings to obtain uniformity in growth and flowering traits. Male sterile lines are also propagated and maintained by cuttings.
Seeds of many cultivars are easily available and germinate quickly. The seed rate is 800-1000 grams per hectare. Marigold seeds germinate well at temperatures ranging from 18 to 30oC. Nursery beds are prepared after thoroughly mixing well rotten farmyard manure. Raised nursery beds of convenient size (normally 1 m wide and raised to 15 cm) are prepared. Before sowing, the seeds are treated with Captaf or Bavistin. The nursery bed may also be drenched with 0.1% Bavistin. Seed should be finely covered with farmyard manure or leaf mould. Watering should be given with the help of a fine rose can. Formation of hard pan should be prevented for good emergence of the seedlings. The sowing should not be too dense to prevent the damping off of the seedlings. The seeds can be sown from mid October to mid November. The seedlings are ready for transplanting in 25-30 days after seed sowing.
Marigold is also propagated through cuttings to produce true to type plants and to maintain male sterile lines. Cuttings of 6-10 cm length can be planted in sand. The base of the cuttings may be treated with commercial formulations of Indole butyric acid (IBA) to promote the rooting.
The seedlings are transplanted in the field after one month of seed sowing. A spacing of 45 x 45 cm for African marigold and 30 x 30 cm for French marigold has been found to be optimum for commercial cultivation. The seedlings at the time of transplanting should be disease free and should have 3-4 true leaves. Light irrigation should be given after transplanting.
It was observed that fresh and dry weight of plants increased for 70-75 days until flowering and need for nitrogen lasted till this stage. Potassium was required till seed formation (90-100 days). It responds well to both macro and micro nutrients in addition to organic manures. Well rotten farmyard manure @ 30tonnes should be incorporated per hectare well in the soil at the time of soil preparation. In addition to farmyard manure, it is advisable to apply 120 kg/ha of nitrogen and 80 kg/ha each of phosphorus and potash for getting good vegetative growth and flowering. Whole quantity of phosphorus and potash should be applied at the time of land preparation. Nitrogen is to be applied in two split doses. The first dose should be applied 20 days after planting and the second dose 40 days after transplanting. It will be better if two foliar sprays of 0.2% urea are done at an interval of 15 days.
In African marigold, because of apical dominance the plants grow tall and lanky with very few branches. Such plants are susceptible to lodging and the flower production will be less. Pinching is done to break apical dominance and to encourage axillary branching and thereby increasing flower production. French marigold does not require pinching. Pinching slightly delays flowering but improves flower production. Pinching 40 days after transplanting has been found to be optimal.
The cultivars of African marigold usually grow taller and growth retarding chemicals have been recommended for reducing the height and improving the appearance as potted plant. SADH 2500 ppm reduced plant height and improved the foliage colour. When 2-5% solutions of CCC were sprayed, there was a marked improvement in growth and flowering. The treated plants were dwarf in nature. Repeated applications of GA3 slightly improved height and flowering.
For all stages of vegetative growth and flowering, sufficient amount of moisture is essential. Moisture stress at any of the vegetative and flowering stages markedly influences growth and flowering. The frequency and quantum of irrigation is dependent on species, variety, soil and season. During the summer months, the plants are liable to dessication due to hot winds. Therefore the plants should be irrigated according to the atmospheric conditions. Winter crop requires irrigation at an interval of 8-10 days.
In marigold, weed control is laborious and it involves lot of cost. If weeds are not controlled in time, growth, flowering and productivity are drastically affected. At least 5-6 manual weedings are required for the entire cropping period. Alachlor @2.5-3.0 kg/ha is effective in controlling the weeds during the entire cropping period.
Harvesting and Packaging
The flowers are harvested when they are fully open and have attained full size. Field should be irrigated before plucking as flowers will retain freshness for longer period after harvest. After harvesting, the flowers are packed in small and big bamboo baskets.They are then transported to nearest or distant markets by buses or lorries. It is better to harvest the flowers in the morning and to store them in a cool place before packing.
Diseases and insect pests
Damping off (Pythium sp., Rhizoctonia sp.)
This disease affects the seedlings. Before emergence brown coloured spots appear on radicle and plumule causing pre-emergence death of the seedlings. After emergence, brownish necrotic spots appear on the collar portion of the seedlings. These necrotic spots in severe cases form a girdled portion leading to the collapse of seedlings. The disease can be controlled by prophylactic drenching of nursery beds with Captaf and Bavistin. Seed treatment with 0.1% Captaf will also reduce the incidence of the disease.
Leaf spot and blight Alternaria sp., Cercospora sp., Septoria sp., Colletotrichum sp.
Various pathogens cause leaf spot and blight in marigold. The symptoms appear as small brownish spots on leaves. In case of Alternaria infection, the spots show concentric circles. In severe cases, the infection may spread to inflorescence. In case of Cercospora, the spots show bird eye appearance with dark border and light coloured centre. Septoria infection is marked by black spots. The blight of marigold is caused by Colletotrichum sp.The infected plants show burnt appearance. These leaf spot diseases can be controlled by Dithane M-45 0.3% spray.
Inflorescence blight : (Alternaria zinnae)
Initially minute brown spots appear which enlarge into blotches. The spots show zonations or concentric circle (Target board) pattern. Inflorescence gives a burnt appearance in severe cases. This disease can be controlled by Dithane M-45 (0.3%) spray.
Flower bud rot : (Alternaria dianthi)
This disease appears on inflorescence or young buds which show discoloured appearance in initial stages. The buds show dry rotting in case of severe infection. Bud rot can be controlled by Dithane M-45(0.3%) spray.
Powdery mildew: (Oidiumsp., Leveillula taurica)
Whitish tiny spots appear on leaves initialy. The entire plant shows powdery appearance in severe cases. The disease can be controlled by Karathane (0.1%) sprays.
Viral diseases : (Cucumber Mosaic Virus, Aster Yellow Virus)
Infected plants show chlorotic streaking and yellow mosaic appearance. Infected plants get dwarfed. Roguing of diseased plants and insecticidal sprays to control vector population prevent the spread of the disease.
Red spider mite: (Tetranychus sp.)
Mites infect old plants. The diseased plants give dusty appearance. The plants show webbed appearance. The disease can be controlled by spraying Kelthane (Dicofol) 0.1%
Hairy caterpillar: (Diacrisia obliqua)
In the initial stages they eat away the foliage later stages they eat away the ray florets of the inflorescence. This can be controlled by spraying Nuvan( 0.2%).
Leaf hopper: (Empoasca fabae)
The hoppers suck sap from the leaves and stem. The infected plants show cupped or rolled leaves and give wilted appearance spraying of Metasystox (0.2 %) controls the hoppers.
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