T Jamir, LK Baishya, LJ Bordoloi, DJ Rajkhowa and A Aziz Qureshi
Sunflower (Helianthus annus L) is a photo insensitive oilseed crop; which can be successfully grown in any season. Commercially available sunflower varieties contain 39 to 49% oil. Sunflower oil is generally considered a premium oil, good for heart patients because of its high level of unsaturated fatty acids and lack of linolenicacid and bland flavour. The primary fatty acids in the oil are oleic and linoleic (typically 90% unsaturated fatty acids), with the rest consists of palmitic and stearic saturated fatty acids. Sunflower oil used for frying purposes tends to enhance shelf life of snacks and used as an ingredient of infant formulas requiring stability. Non-dehulled or partly dehulled sunflower meal is a good diet for ruminant swine and poultry feed. Protein percentage of sunflower meal ranges from 28% fin whole seeds to 42% in dehulled seeds. Use of sunflower oil (and other vegetable oils) as a pesticide carrier and in the production of agrichemicals, surfactants, adhesives, plastics, fabric softeners, lubricants and coatings has been explored. Use of sunflower seed for birdfeed or in human diets as a snack, has became popular. Sunflower can also be used as a silage crop.
Climate: Sunflower is a photo insensitive and tolerant of both low and high temperatures. Sunflower seeds will germinate at 10°C, but temperatures of at least 23 to 27°C are required for satisfactory germination. Seedlings in the cotyledon stage have survived temperatures down to below 3°C. Optimum temperatures for growth are 23 to 27°C, but a wider range of temperatures (17 to 37°C) show little effect on productivity. Extremely high temperatures have been shown to lower oil percentage, seed sets and germination. Research conducted at ICAR RC for NEH Region, Nagaland Centre have shown that sunflower crop comes up very well in Nagaland during rabi season in the valley and summer in the hills.
Soil: Sunflower will grow in a wide range of fertile soil types; sandy loam to clays with pH value ranging from 6.0 to 7.5.
Seedbed Preparation: Conventional systems can increase the availability and improve the distribution of potassium and nitrogen and increase the seed zone temperatures of soil. It break up soil limiting layers, destroy weeds and provide a suitable seedbed and at the same time ensures maximum rainfall infiltration, as well as prevent wind and water erosion.
Selection of Variety
Sunflower varieties and hybrids grown in India
Variety Source Average yield (kg/ha) Oil content (%)
KBSH-53 UAS, Bangalore 900 – 1800 36-39
LSFH- 171 IIOR, Hyderabad 1000-1500 36-39
KBSH-44 UAS, Bangalore 1400-1600 36-38
KBSH-41 IIOR, Hyderabad 1300-1600 39-40
DRSH-I IIOR, Hyderabad 1400-3000 40-42
Seed and Sowing: Healthy seed of improved variety/ hybrid should be selected for sowing. The seed should be treated with Captan/bavistin @ 3g per kg of seed before sowing. First week of October to first week of November is the normal sowing time for rabi crop. However, sunflower can be planted at a wide range of date. Planting to an extent which causes flowering, seed filling coincide with periods of high temperature will result in decrease of crop and oil yield.
Method and Rate of Seeding: A spacing of 45 cm should be maintained between two rows while seeds should be drilled in 5-6 cm deep furrows at the rate of 18-20 kg per hectare for pure stand. Plant population has a strong effect on seed size, head size, and percent oil. A medium to high population produces higher oil percentage than under low populations and the smaller heads dry down faster at higher plant populations.
Fertility and Lime Requirements
Fertilization: Sunflower utilizes soil nutrients exceptionally well. The main reason for this is the finely branched and extensive root system. Its roots come into contact with nutrients which cannot be utilised by other crops.
Macro-nutrients: Sunflower normally reacts well to nitrogen and phosphorus fertilization, where there is a shortage of these elements in the soil. It is therefore, essential that any fertilization programme for sunflower should be based on soil analyses. It significantly limits unnecessary fertilization costs. After levelling of the land, fertilizer @ 60-40-20 NPK for low fertility and 40-30-20 kg/ha of NPK respectively for high fertility soil should be placed in furrows 8-10 cm deep and 4-5 cm away from the seed at the time of sowing. To increase the efficiency of nitrogen 60% of nitrogen may be applied as basal and remaining top dressed 40 days after sowing. Furrow lime application @500kg/ hectare is essential to maintain soil pH.
Molybdenum and boron: Shortages of boron and molybdenum often limit the growth and yield of sunflower. To avoid problems concerning these two elements, care should be taken to apply fertilizer containing boron and to ensure that seeds are treated with molybdenum prior to planting.
Irrigation: A critical time for water stress is the period 20 days before and 20 days after flow-ering. If stress is likely during this period, irrigation will increase yield, oil percentage and test weight. Protein percentage, however, will decrease.
Weed Control: Young plants are highly sensitive to strong weed competition and cannot develop fast enough to form a full shade covering which can suppress weed seedlings. Therefore, the first 6 weeks after planting are a critical period for the crop. Yields can be increased significantly by keeping fields free of weeds during this time.
Diseases: The major diseases include rust, downy mildew, Verticillium wilt, Sclerotia stalk and head rot, phoma black stem and leaf spot. Application of Indofil M-45 @3ml/liters followed by Carbendazim@2ml/liters at 10 -15 days intervals can control of the major diseases of sunflower.
Crop rotation: Sunflower should be grown in rotation with other crops as the risk of diseases and weeds increase with monocropping. A yield and quality advantage is often measured in a follow-up maize or sorghum crop. Weed and pest problems decrease with crop rotation. In Nagaland it can be grown after rice crop.
Harvesting: Harvesting should commence when 80% of the sunflower heads turn brown in order to minimise losses caused by birds, lodging and shattering. Sunflower is generally mature long before it is dry enough for combining. The sunflower plant is physiologically mature when the back of the head turned from green to yellow and the bracts turn brown, about 30 to 45 days after bloom and seed moisture becomes about 35%. The total growing period (from seeding to harvesting) for sunflower ranged from 125 to 130 days.
Harvesting methods: Harvesting is done either manually or mechanically. Manual harvesting is practiced by cutting the crop with a sickle or knife. Commercially available sunflower headers are useful in decreasing loss of seed as the crop is direct combined.
Storage: Seeds should be below 12% moisture for temporary storage and below 9% for long-term storage.
Economics of Production and Markets
The average cost of cultivation for sunflower in Nagaland is Rs. 15000/- (Approx) and gross income Rs.48000/- (as average yield is 1500kg/ha). This indicates that the crop is more beneficial to the farmers of Nagaland.