Growing Saffron Plants Techniques, Methods:
The following content is all about Growing Saffron Plants.
INTRODUCTION TO GROWING SAFFRON PLANTS:
Saffron (Crocus Sativus), an autumn flowering perennial plant is believed to have descended from the wild saffron (Crocus Cartwrightianus) in the eastern mediterranean region. This plant is cultivated extensively in mediterranean regions like Spain, Turkey, France, Austria, England, Greece and Iran. In India two places are well known for the cultivation of saffron: Jammu and Kashmir and Himachal Pradesh.
The saffron plants grow to a height of 20 cm and bear lilac or purple color flowers. The corm is used for growing new plants. Stigmata, a part of the flower is dried and is used as a spice. It is red in color and is estimated to be the most expensive spice round the world. Therefore, sometimes it is addressed as ‘red gold’. The most unique feature about this plant is that it can almost be grown anywhere in the world.
While considering low-input agriculture options saffron is chosen because of its agronomical behaviour i.e. can resist adverse climate, autumn flowering, low requirement of fertilizers, low water requirement and highly adaptable to various soil conditions.
In India, this spice is addressed depending on the state where it is being used. In Hindi as kesar, in Bengali as jafran, in Malayalam as kunkumapoove, in Kashmiri as Kong, in Kannada as kumkuma, in Urdu as zafranekar, in Telugu as kumkumapovu.
Saffron is widely used in cooking and also has some medicinal values. It is used as a colouring and flavouring agent in multiple cuisines. The Ayurveda prescribes saffron for ailments like arthritis, infertility and liver problems. Saffron is mentioned as ‘varnya gana’ in the Ayurveda which means fairness and glow. Therefore it is also used in making cosmetics.
SOIL AND CLIMATE CONDITIONS FOR GROWING SAFFRON PLANTS:
Soil is of prime importance while growing saffron plants. A neutral clay-calcareous soil or silty soil is most ideal for these plants. Organic content of the soil also has to be maintained high while growing saffron plants. The pH level of soil has to be within the range of 6.0-8.0. These plants do not require much moisture and can withstand dryness in summer during growth. Too much of clay is not suitable for saffron plants.
Saffron is categorized under heat- tolerant plant. Sunlight is essential for growing saffron; they perform low in shady environment. Saffron plants are best grown in dry, moderate and continental climatic zones where the summer temperatures range between 35-40 degree Celsius and winter temperatures in between -15 to -20 degree Celsius. Extreme frost can be harmful because the corms are affected. If there is extreme dryness during spring then little irrigation is required. Sufficient regular rainfall in spring can also help remove dryness and aid in better flowering and corm lets.
PROPAGATION METHOD FOR GROWING SAFFRON PLANTS:
New saffron plants are grown from compressed underground stems called corms. The simple method of obtaining a corm is cutting it from the main stem. The obtained corm can be dusted using a fungicide powder and dried for about 48 hours and can be planted for growing a genetically new plant. Seed propagation is not an option for saffron plants and therefore it is said to belong to the species of sterile triploid.
CUTIVARS FOR GROWING SAFFRON PLANTS:
Three different varieties of saffron are grown around the world.
Aquila: This variety is grown in Italy. The threads are less dark in color when compared to Kashmir saffron but since it is grown in bulk it is widely available and less expensive.
Crème: Generally grown in the U.S and other countries. It is easily and economically available saffron in the market.
Lacha: This is considered to be the best variety available in the market and is exclusively grown in Kashmir soil. The threads are dark crimson red in color. It is also very expensive owing to its quality.
CROP ROTATION FOR GROWING SAFFRON PLANTS:
Analysis has shown that a minimum of 3 to 8 years gap has to be maintained for growing saffron plants on the same soil. Research shows that when saffron plants are grown on the same soil there is a drastic decrease in the stigma production and high increase in the weed. Therefore, saffron is included in the list of crop rotation. Wheat and legumes are rotated with saffron to earn profit and to maintain the fertility of the soil.
PLANTING TECHNIQUES FOR GROWING SAFFRON PLANTS:
Four major factors are taken into consideration for growing saffron and producing high yield: planting cycle, planting time, planting method and seed rate. Once a corm is planted, it is retained in the soil for many years and produces baby corms which help the production cycle but with reduced yield. Traditional planting cycle was of 10 to 12 years duration but recent recommended practise is 4 to 5 years planting cycle.
Generally for commercial saffron cultivation a virgin land is chosen which means that no prior tubers or corms of saffron plants were planted in that land. The soil of the land is tilled to a depth of 20 to 50 cm’s to maintain well-aired and loose plant beds. July, august and September are ideal for planting corms and harvesting is done after approximately eight weeks that is in the months of October and November. Saffron plants are grown on raised beds which facilitate sufficient irrigation and drainage.
Each corm is planted 7 to 15 cm deep within the soil because more the depth less is the multiplication of corm. This in turn produces less harvest but high quality blossom. Corms are planted in rows with each row separated by a distance of 15-20 cm. Holes are dug and the corms are planted, the soil that was dug is used to cover up the corms. After a block of rows some empty space (25 cm) is maintained to facilitate irrigation, pest control and harvesting techniques. Spacing between the corms is very important factor for growing saffron and this is usually dependent on grubbing.
Corm size is always essential for the saffron yield. Minimum size of the corm is 1g and maximum is 20g. Generally, a corm of 2-8g has no flowering potential whereas corm with size 8-14 g are productive and corm size beyond 14g have maximum flowering capacity. Before planting, all the corms weighing more than 8g are sorted out and the outer scales are removed. Corms are planted such that their apical bud is positioned upward.
WEED CONTROL FOR GROWING SAFFRON PLANTS:
Weeds in the soil where saffron cultivation is done can deplete the soil of its nutrients. Weeds are removed manually and extra care is taken not to harm the corms or bulbs of saffron plants. At some places farmers do not practise weeding, they allow the weeds to grow and harvest them. Two best seasons for weeding are November and March. In India no chemicals are used for weeding but in some places simazine (gesatop 50%) or astrzine (gesaprim 50%) are used @10kg/ha for weed control. Occasional hoeing during June and September keeps the soil aerated and also helps remove weeds
FERTILIZERS FOR GROWING SAFFRON PLANTS:
Growing saffron for years can reduce the fertility of soil because the saffron plants drain the nitrogen, phosphorous and potassium from the soil. Therefore a system of integrated nutrient management (INM) is suggested to maintain the fertility of the land. The composition of fertilizers recommended by the INM is inorganic fertilizers: nitrogen, phosphorous and potassium in the ratio of 90:60:50 kg/ha respectively. Nitrogen is applied in the form of urea @145.728kg/ha, phosphorus in the form of DAP@132kg/ha, potassium in the form of MOP@ 83kg/ha, well decomposed farm yard manure@10 tons/ha and vermicompost @25kg/ha are applied during the second hoeing of existing plants and while planting fresh corms as a basal dose to the soil. About half dose of Nitrogen fertilizer has to be applied again during the vegetative phase in the month of November.
IRRIGATION REQUIREMENTS FOR GROWING SAFFRON PLANTS:
Saffron plants can survive in sufficient moist land. They do not require extreme wet soil. Since rain is unpredictable in India these days, a method of sprinkler irrigation is followed. In this method 7lac l/ha of water is distributed over 10 irrigation cycles with a seven day interval. Irrigation during the pre-flowering phase i.e. from last week of august to mid October is very essential as this facilitates flowering and requires seven cycles of irrigation. The vegetative phase i.e. corn development stage during November requires the last three irrigation cycles.
PESTS AND DISEASES CONTROL IN GROWING SAFFRON PLANTS:
Wood mice, rabbits, voles and porcupines are a threat to saffron plants. These pests are fond of corms and leaves of the plant. Fumigating the burrows of these pests with aluminium phosphide@2pellets/burrow or by 5 to 10 grams of aluminium phosphide pouch/burrow and covering them with wet mud is a method to control the pests.
Saffron plants are generally affected by three diseases:
Fusarium wilt disease in growing saffron plants: The disease causing agent is Fusarium oxysporum. The symptoms of the disease are corm rot, rotting of the basal stem during flowering stage and shoots turning yellow and wilting away.
Violet root rot in disease in growing saffron plants: The agent causing this disease in saffron plants is Rhizoctonia species. Appearance of chlorotic leaves and wilting of the entire plant are symptoms of this disease. This form is contagious and needs to be addressed immediately.
Rhizoctonia Crocorum disease in growing saffron plants: The disease is caused by Rhizoctonia species. Start of infection in the leaves and travels downward to the roots which ultimately rot and violet mycelial growth are symptoms of the disease.
To avoid fungi on saffron plants, the corms are treated with anti-fungal solutions such a copper-based solution or benomil.
HARVESTING OF SAFFRON PLANTS:
The blooming season of saffron plants starts in October and continues for three weeks. ‘Blanket days ‘is the term used to signify the intense blossom period of about 2 – 6days. Blooms are harvested during the early morning or before noon so that the petals do not wilt. Generally the sleeping blooms are also harvested to obtain high quality threads. Flowers have to be collected in plastic baskets or paper craft bags with proper aeration and hand gloves should be used to maintain hygiene.
Once the blooms are collected, the process of striping is done i.e. the stigma or the thread within the flower is carefully and manually removed. This process has to be done within 10-12 hours of flower collection to obtain maximum recovery of pistil. If the separation of stigma is delayed by 36-72 hours then it would result in loss of recovery.
DRYING TECHNIQUES OF SAFFRON PLANTS:
Traditional way used by farmers for drying saffron is shade drying for about 27 to 53 hours. Average temperature for drying saffron is 40-50 degree Celsius. Drying reduces the weight and size of the stigma by 80%. Hot air dryers, solar dryers, coal dryers and dehydrators are modern ways to dry the stigma. If bulk drying has to be done then a room with temperature of 30 to 35 degree Celsius is maintained and saffron threads are heated for about 10 to 12 hours. Whereas a dehydrator set to 48 degree Celsius can dry the threads in 3 hours. Drying plays a very sensitive role during the entire saffron growing cycle. Over drying can reduce the quality and price of saffron.
YEILD OF SAFFRON PLANTS:
The yield of saffron plants is unpredictable as this depends on the biological and environmental factors. Usually it is believed that one hectare of saffron plants produce 10 to 15 kg of dried stigma. Kashmir yields 2.5 kg/ha of saffron.
GRUBBING TECHNIQUE FOR GROWING SAFFRON PLANTS:
Once a yield of saffron is obtained, the plants turn brown and wither off. At this stage the corms are not productive, so a method called grubbing is done to collect all the corms and store them for future. After a period of four years the cropping capacity of corms becomes negligible. So, in the fifth year grubbing of corms is done. Grubbing is upturning the saffron fields manually or mechanically. The corms are collected manually and cleaned. The unwanted things around the corms are removed and they are sorted according to size for future planting. Corms cannot resist heat and bright sunlight, so they are stored in a well-ventilated dark area for next planting season.
STORAGE METHODS IN GROWING SAFFRON PLANTS:
Once the drying stage is complete, they are allowed to cool and then wrapped in tissues or foils. They have to be stored in a cool dark place for minimum 30 days before being ready to be used. Saffron threads with 8% moisture are stored in air-tight containers at 10 degree Celsius for about 6 months. High moisture and temperature can lead to a faded pigment in saffron.