Marigold is one of the most important flower crops which is used extensively in all ceremonies. It has value both as loose flower as well as cut flower. The short duration of crop wider adaptability, ability of growing in different seasons of year and moderate price made it a popular and most widely used flower crop. The flower was introduced in our country during 16th century. Marigold is used as a cut flower, loose flower, as garden plant, as a pot plant as well as used for its medical properties.
Type of Marigold
• Tegeteserecta commonly called as African marigold.
• Tegetespatula commonly called as French marigold.
The characteristics of T. erecta are that plant is annual, hardy, erect and profuse branching and grows upto 90cm high. Leaves and leaflets have pinnately and lanceolate to serrated appearance. The flower colour varies from yellow, lemon, golden yellow to orange which are double or single petalled.
The main characters of T. patula are the height of the plant goes upto 30cm and its hardy annual. The colour of leaves ranges from dark green and reddish stem with bushy appearance of the plant. Leaves have the same arrangement as of T. erecta.
Ideal soil for Marigold cultivation
The most ideal soil for the cultivation of marigold is considered soil having pH range from 7.0 to 7.5 i.e. neutral. The soil should be well drained, well aerated, rich in organic matter and soil properties should be optimum for plant growth and development. As far as French marigold is concerned it loves a soil rich in organic matter and light in texture. The African marigold at the other hand loves moist soil. However, marigold can be grown in any type of soil provided the pH, EC, OC, and available NPK apart with other essential elements are at optimum level.
Marigold is normally cultivated in Maharashtra, Karnataka, Gujarat, Andhra Pradesh, Tamil Nadu and Madhya Pradesh.
Marigold grows in wide range of climatic conditions and can be grown round the year. However proper climate plays an important role in quality higher yield per unit area. The most ideal temperature requirement range for marigold is 18-350C. Under the temperature range of 18-200C the growth of plant is excellent. The temperature above 360C causes reduction in flower stalk length, flower size, and yield. As far as low temperature below the optimum level is concerned the frost attack causes damage to crop. So optimum temperature and appropriate environmental conditions like optimum light, humidity etc. influence both production and productivity.
The land is thoroughly ploughed two times followed by leveling of field. Soil solarization has been recommended so as to come over the problem of insect pests.
Propagation and Nursery raising
Marigold is commercially spread through seeds; however, propagation by cuttings is practiced for maintaining the true to type conditions. The recommended seed rate is 1.5 kg/ha. The optimum temperature for germination is from 180C to 300C. However, the seed germination can be aided under protected conditions.
The nursery beds of 1m breadth and of any convenient length are prepared by digging the soil at least up to 30cm. The beds should be raised one so as to protect it from adverse conditions like uneven rains etc. The soil should be properly prepared, leveled and cleaned. The addition of FYM improves soil fertility and helps in excellent germination rate. To protect the seeds from soil borne pathogens and insects like ants, the dusting of BHC to beds and treatment to seeds helps to manage these problems. Seeds are sown in line and liberal watering is done as seeds need water to come for germination. To aid the process of germination the dark conditions with straw are provided for 3 days and germination takes place within 7-10 days. The seedlings are transplanted at 4 true leaf stages which come within one month.
The transplanting is carried out after a seedling attains 4 leaf stage which is around one month after sowing. The process of transplanting should be carried out during the cool hours of the day, i.e. either in morning or evening but evening time is preferred as seedling get enough cool hours of night to adapt itself under new atmosphere. After transplanting liberal watering should be done. Care should be taken that soil remain moist but not too wet which may invite the problems like damping off. The planting density or spacing is adjusted as per the type of marigold as well as on the basis of cultivar. The usual spacing for African marigold is 45cm x 45cm and for French marigold 25cm x 25cm.
The irrigation scheduling depends upon the season and soil type. Under heavy soils less irrigation is given compared to light soils. Besides this the stage of growth as well determines the quantity of water required. During the peak vegetative stage if there is shortage of water the growth is influenced badly which in turn influences flowering. In general, the irrigation is given at weekly interval during summer and at 15 days interval during winter.
Proper manuring and fertilization play an important role in growth, development and flowering of plant. The incorporation of organic manures like FYM, vermin compost etc. helps in maintaining soil properties and improves moisture and nutrient holding capacity of the soil. The application of inorganic fertilizers maintains the available soil macro and micro nutrient level and is important for crop growth & flowering. Among the nutrients primary macro elements NPK are of prime importance as N is related with growth and PK with flowering and the combined effect of all the three provides excellent vegetative growth and higher quality yield Nitrogen plays a key role in enhancing qualitative as well as quantitative characteristics through its influence on growth and development. Phosphorus encourages root development and thus influence growth and flowering. Potassium leads to hardiness of plant and improves resistance to cold, diseases especially powdery mildew. Calcium helps in root growth and helps in translocation of carbohydrates, magnesium forms dark green colour to leaves besides enhances phosphorus uptake, manganese acts as a catalyst for enzyme activity and its function cannot be replaced by any other nutrient Iron helps in chlorophyll formation. Boron promotes the calcium use efficiency and deficiency causes shoot tip and malformation. Therefore, lack of any nutrient has adverse effect on plant growth and development.
At the time of soil preparation FYM @ 25 tones/ha is incorporated. The recommended dose of 90 kg N, 90 kg P2O5 and 75 kg K2O is applied per ha. Phosphorus and potassium are given as common basal dose while as N is given in three split doses. Half N is given as a basal dose and remaining half 30 and 45 days after transplanting as a top dressing. Try should be to apply nutrients during the cool hours. The INM i.e. integrated nutrient management concept is now a days found successful for marigold as it provides excellent size of bloom with good weight, colour and shine. In this method half of the nutrients are applied through organic sources and half through inorganic sources. The use of bio fertilizers is found successful for improving yield and available soil nutrients and fertility besides it reduces the amount of NP application through inorganic sources and is eco-friendly. Azotobacter helps to fix atmospheric nitrogen and saves around 30kg N/ha per year while as phosphate solubilizing bacteria (PSB) saves around 20-30 kg P2O5/ha per year through effective solubilization. So, application of nutrients through INM paves a way for better results.
Integrated weed control should be followed to keep weed population below the level of damage as these harm yield through nutrient competition as well as aids the insect & diseases venues. The use of pre-emergence followed by post emergence and hand weeding gives excellent results. The assessment shows that 5-6 weeds during the crop period are practiced.
Pinching is the most important cultural operation for improving qualitative as well as quantitative characters of marigold. The apical dominance is the main factor which restricts the growth of lateral shoots. The apical dominance is due to auxin. After transplanting of 45 days branches of the plant are pinched to improve the growth of laterals. The time of 45 days is fixed as plant first grows to its proper size and then develops lateral buds. So, this stage is stable for pinching as the time starts the encouraging of laterals. The formation of laterals produces more flowers from a single plant thus improves production and productivity. At the early stages disbudding of apical shoots is performed so that flower formation should be respected in the early stage which may either disturb the whole plant production in the long run.
It means providing support to the tall plants. The African type marigold plants grow tall and needs to be staked with the help of bamboo sticks otherwise, lodging and bent stem may affect proper display of the plant.
Marigold flowers are plucked when they have attained the full size. Harvesting of flowers is done in the evening, just before the flowers are fully opened. Field should be irrigated before plucking as these flowers keep for life for longer period after harvest. Fresh flowers are packed in bamboo baskets or gunny bags for transporting to the local markets.
The yield of marigold flowers varies considerably depending upon the season, fertility of the soil and variety. The yield of African marigold and French marigold varies from 8-12 t/ha and 11-18 t/ha respectively.