Okra-Kharagpur

  Introduction:  
  Okra or Ladies finger popularly known as 'Bhindi' is one of the important vegetables grown throughout the tropical, sub-tropical and in the warmer parts of temperate regions in India. The nutritional value of 100g of edible okra is characterized 1.9 g protein, 0.2 g fat, 6.4 g carbohydrate, 0.7 g minerals and 1.2 g fibers. Okra has a good potential as a foreign exchanger crop. It is cultivated in 0.432 M ha area with the production of 4.528 Mmt and productivity of 10.5 mt/ha. The major okra producing states are Uttar Pradesh, Bihar, Orissa, West Bengal, Andhra Pradesh, Karnataka and Assam. In West Bengal, 0.830 M mt of Okra is produced from 72,600 ha with an average productivity of 11.4 mt/ha. The crop is also used in paper industry as well as for the extraction of fiber.  
     
  Crop varieties:  
  Okra (Abelmoschus esculentum (L.) Moench) Plant belongs to the family Malvaceae. The crop varieties are Kamini, Pusa Mukhamali, Parbhani Kranti etc. are commonly cultivated varieties.  
     
  Conventional practices:  
  Generally farmers grow locally available varieties with check basin or furrow method of irrigation. Standard practices of nutrient and plant protection measures are rarely adopted.  
     
  Suitable agro-climatic conditions:  
  Okra is a warm-weather crop. It can be grown in the temperature range from 22o to 35oC. Okra is susceptible to frost and cold injury below 12oC temperature.  
     
  Suitable soils:  
  Okra can be grown on a wide range of soils, having good internal drainage. Soils with high organic matter are preferred. Application of lime or dolomite may be done in acid soil to bring the pH in the range of 6.0 - 6.5.  
     
  Preparation of land:  
  Intensive tillage is required for the land preparation of Okra. Deep (20-25 cm) ploughing followed by cross harrowing is done to make the soil friable and loose. One or two planking's are also needed to make the soil surface smooth and level.  
     
  Soil sterilization:  
  The sterilization of the soil can be achieved by both physical and chemical means. Physical control measures include treatments with steam and solar energy. Chemical control methods include treatments with herbicides and fumigants. Soil sterilization can also be achieved by using transparent plastic mulch film, which is termed as soil solarization. During soil solarization, the incoming solar radiation penetrates the transparent plastic film (150 micron) and is absorbed in the soil. The absorbed radiation converts into heat energy, which raises the soil temperature and kills many soil-borne organisms including plant pathogens and pests.  
     
  Planting:  
  Sowing is done in two seasons: end of January for the summer crop and end of May for the rainy season crop. The seed rate for the summer crop is 18 to 20 kg /ha and 10 to 12 kg /ha for the rainy season crop. A spacing of 60 x 45 cm or 60 x 30 cm is generally adopted.  
     
  Drip Irrigation System:  
 
Area 1 ha
Planting geometry 60cm x 30cm
Variable items 75 mm F PVC/HDPE pipe-54 m, 75 mm F PVC/HDPE pipe-102 m, 12mm F LDPE Lateral-8400 m, Online dripper (2 l/h)-13,888 Nos., Control valve- 2 Nos., Flush valve- 2 Nos., Tees/bends-1 No., Accessories
Fixed items Screen filter (15m3/ h) -1 No., Bypass assembly: 1 No., Fertilizer applicator –1 No., Accessories
 
     
  Irrigation scheduling:  
  The crop requires adequate moisture in the soil during summer months for faster growth. Drip irrigation is most suitable to the crop as it provides uniform moisture throughout the season. The daily water requirement of Okra crop is 2.4 l/day/4 plants during early growth stage and 7.6 l/day/4 plants during the peak growth stage. The irrigation system should be operated daily for 75 minutes during initial growth stage and for 228 minutes during peak growth of the crop with an emitter capacity of 2 lph. Irrigation on each day or on alternate days with On-line type of drippers is preferred.  
     
  Application of fertilizers:  
  In order to maximize the yield about 30 t of FYM, 350 kg Super phosphate, 125 kg Murate of Potash and 300 kg Ammonium sulphate should be applied in the rows before sowing for one hectare of land. Nitrogen should be applied through fertigation in three split doses.
  
     
  Weed control:  
  As Okra is harvested over a long period, weed control happens to be an important cultural operation. Shallow rooted inter-row cultivation and hand weeding may be used to minimize weeds in the inter row zone. Black plastic mulch may be used to suppress weed growth. The black plastic mulch (150 micron) also keeps the soil warm and encourages plant growth.  
     
  Plant protection:  
  The control measures for insects, pests and disease depend upon type and intensity of the problems. The control measures for the main pests and diseases are stated below.  
  Flea beetle is the major insect for Okra. This can be controlled with row covers or applications of Rotenone or Pyrethrin. Okra is susceptible to diseases such as Verticillium, Fusarium and several other fungal diseases in wet season. These diseases can be controlled by proper crop rotation and good garden sanitation practices.  
     
  Harvesting, yield and quality control:  
  Okra is harvested after 60 to 70 days from planting, when pods are 2 to 3 inches long. At this stage the pods are still tender. Longer Okra pods will tend to be tough and fibrous. Round-podded Okra varieties remain tender at longer pod sizes and are good to use for slicing and freezing. Since, Okra grows very fast, it should be harvested on every second day. The pods should not be allowed to mature on the plant because this will inhibit more pods from developing and reduce the productivity of the plant. Handling of okra should be done carefully because the pods bruise easily. The yield of Okra varies from 5 - 7 t/ha in summer to 8 - 10 t/ha in the rainy season.  
     
  Post harvest handling and storage:  
  Okra has a short storage life. A fresh good pod can be stored for 7-10 days at 7-100 C temperature and 90-95% relative humidity. At temperatures below 70 C Okra is subjected to chilling injury, which results in surface discoloration, pitting and decay.  
     
  Cost economics:  
 
Area: 1 ha.
Planting geometry 60cm x 30cm.
Fixed cost of drip system Rs. 99,366
Rate of interest 10.5%
Life of system 7.5 years
Annual cost of drip System Rs. 14,287
Cost of cultivation Rs. 11,500
Expected yield 17 mt/ha
Expected Benefit Cost ratio 2.2
 
     
  For more information, kindly Contact:  
  Principal Investigator, Precision Farming Development Centre (PFDC)
Agricultural & Food Engineering Department, IIT Kharagpur (W.B.) 721 302.
Tel: 03222-283150 (O), Fax: 03222-282244 / 255303 (O), Email: kamlesh@agfe.iitkgp.ernet.in