Precision Farming in Okra

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Okra, also known as “lady’s fingers” and “gumbo,” is a green flowering plant. Okra belongs to the same plant family as hibiscus and cotton. The term “okra” most commonly refers to the edible seedpods of the plant. Okra has long been favored as a food for the health-conscious. It contains potassium, vitamin B, vitamin C, folic acid, and calcium. It’s low in calories and has a high dietary fiber content. Recently, a new benefit of including okra in your diet is being considered. Okra has been suggested to help manage blood sugar in cases of type 1, type 2, and gestational diabetes.

Variety Arka Anamika, Arka Abhay or any popular commercial hybrids.
Soil type Well drained fertile soils  with a pH range of 6.0 to 7.0.
Season Sowing in June-July, Jan-Feb
Seed requirement 2.5 kg
Land preparation

 

Raised bed method: 10-15cm height, 75cm width, convenient length, 45cm inter-bed spacing.
FYM application Apply 10 tonnes of enriched FYM.
Neem cake application Apply neem cake @ 250kg.
Fertilizer Dose 50:30:40 kg N:P:K
Basal fertilizer application Apply 13-10-10 kg N:P:K (60 kg Ammonium sulphate + 60 kg Single super phosphate+ 17 kg Muriate of potash. Mix well and level the beds properly.
Laying of drip line Place one  in-line drip lateral at the center of the bed for which 3330 meter length of lateral pipe is required.
Polyethylene mulching 3330 meter length of mulch film of 1.2m width and 30micron thickness (110 kg)
Spacing and  plant population Double  crop row is maintained per bed of 75cm width. Spacing between the row is 45cm. Make holes of 5cm diameter (7.5cm diameter in hot sunny day) at a distance of 22.5cm along the crop row. 30000 seeds can be accommodated in one acre.
Irrigation Run the drip irrigation daily for a duration of 20 to 40 minutes depending on the crop stage, season and emitter discharge.
Fertigation Schedule fertigation once in 3 days starting from 21 days and ending at 102 days after transplanting for a 4 month duration crop, thus requiring 28 fertigations.
Water soluble Fertilizers per fertigation (Once in 3 days) 0-20 days: No fertigation

21-36 days: 2.0 kg 19-19-19/fertigation (6 fertigations)

39-57 days: 3.0 kg 19-19-19/ +1.0 kg KNO3+1.0 kg urea/fertigations (7 fertigations)

60-102 days: 5kg 19-19-19/ +1.0 kg KNO3+1.5 kg urea/fertigation  (15 fertigations)

(108 kg 19-all+22 kg KNO+ 30 kg urea)

Foliar nutrition Give foliar sprays @ 5g/litre using foliar spray grade fertilizers containing Ca, Mg, Fe, Mn, B, Cu, Zn three times starting from 45 days after transplanting at an interval of 15 days

Insect Pest management

Leaf hopper Image result for leafhopper on okra
Symptoms: 

This pest attacks the crop at its early stage of growth. Small, greenish leaf hoppers; nymphs and adults are found on the under side of the leaves. The adults and the nymphs suck the cell sap from the leaves. As a result the leaves curl upwards along the margins and have a burnt look which extend over the entire leaf area. The affected plants show a stunted growth

Management: 

Apply neem cake @100 kg/acre to beds after germination only and repeat after 30 days.

Sprays PNSPE (40 g/l) or Neem soap (10 g/l)  at 7-10 days interval

Spray  Imidacloprid (0.3ml/l) or Thiamethoxam (0.3g/l) (only once before flowering) or Quinalphos 25 EC (1.5 ml/l) or Dimethoate 30 EC (3 ml/l)

Shoot and fruit borer Image result for Shoot and fruit borer on okra http://www.krishisewa.com/images/articles/2013/okraipm2.jpg
Symptoms: 

Larvae feed on leaves, flower buds, flowers, grains, and bore into pods and fruits. Excrements (faeces / waste) of the feeding caterpillars are evident on damaged plant parts.

Look out for eggs and small caterpillars. Early detection of eggs, or young caterpillars before they bore into the fruits or pods is very important. Once the caterpillars have entered the fruit/pod they are difficult to control and by then they have caused damage. Early detection can be achieved by regular scouting of the crop. Monitoring moth population by using pheromone traps reduces crop inspection time considerably and leads to timely intervention.

Management: 

Spray of  PNSPE (40 g/l)  or Neem soap (10 g/l) at 7-10 days interval. Apply neem cake @ 100 kg/acre after germination and repeat two more times at 30 days interval.

Collect and destroy the infected fruits and grown up larvae. Do not spray insecticides after maturity of fruits. Apply nuclear polyhedrosis virus (HaNPV) @250-500 larval equivalent/ha.

or Cypermethrin  10 EC (1.5 ml/l) or Emamectin Benzoate 5 SG (0.3 ml/l) or Fenvalerate 20 EC (0.5 ml/l) or Lambda-Cyhalothrin 5 EC ( 0.75 ml/l) or Phosalone 35 EC (2.0 ml/l) or Pyridalyl 10 EC (1.0 ml/l) or Quinalphos 25 EC (1.5ml/l)

Aphids
Symptoms: 

This is a polyphagous pest, feeding in colonies and completely covers the shoot tips, buds and lower surface of leaves. Both nymphs and adults suck the sap. They also excrete honeydew on which sooty mould develops. Aphids live in clusters (known as colonies) on leaves and stems. Initially they are present on tender parts of the plant (young shoots and leaves), but as their number increases they can cover the whole plant. As the colony grows winged aphids are produced which fly away looking for new plants to start a new colony.

Management: 

Thoroughly spray neem or pongamia soap (1%) or pulverized neem seed powder extract (PNSPE) 4%.

Onion, garlic and Mexican marigold repel aphids. Try planting few near the crops.

Try blasting aphids with a strong jet of water. Because of their weak legs, many of the dislodged aphids will not be able to crawl back up the plants. Repeat every few days until the problem is under control.

Aphids are especially attracted to mustards. You can plant these near more valuable plants as traps for the aphids.

Chilli pepper 
Cut half a kg of hot chilli peppers in small pieces and boil them in 4 litres of water for 20 minutes. Add equal amount of soapy (bar soap) water, cool and spray (KIOF). or

Pulverise 100g chillies in a mortar, shake vigorously with 1 litre of water and filter through a cloth. Dilute 1 part of this mixture with 5 parts of soapy water before spraying (G. Stoll, 1988). Chilli also repels ants.

or   Acetamiprid (0.15g/l) or  Imidacloprid 17.8 SL (0.2 ml/l) or Thiamethoxam 70 WS (0.3 ml/l)

Mites Related image
Symptoms: 

The infestation of mites is mostly observed during the warm and dry periods of the season. Nymphs and adults lacerate the leaves resulting in whitish grey patches and affected leaves become mottled, turn brown and fall. Mites usually extract the cell contents from the leaves using their long, needle- like mouthparts. This results in reduced chlorophyll content in the leaves, leading to the formation of white or yellow speckles on the leaves. In severe infestations, leaves completely desiccate and drop off. The mites also produce webbing on the leaf surfaces in severe conditions.

Management: 

Prune leaves, stems and other infested parts of plants well past any webbing and discard in trash (and not in compost piles).

Spray Pulvarized Neem Seed Powder Extract (PNSPE) (4%) or Wettable Sulphur 80WP (3g/l) or Dicofol 18.5 EC (2.5 ml/l) or  Quinalphos 25 EC (1.5ml/l)  or  Fenazaquin 10 EC (2.5 ml/l) or Fenpropathrin 30 EC (0.3 ml/l).

Spray lower surface of the leaves where mites are generally found.

Disease management

Powdery mildew Image result for powdery mildew on okra
Symptoms: 

Disease appears on all foliar part as white to dull white, powdery growth. This white growth quickly covers most of the leaf surface and leads to heavy reduction in photosynthesis area. The disease is most commonly observed on the upper sides of the leaves. It also affects the lower sides of leaves, young stems, buds, flowers and young fruit. Infected leaves may become distorted, turn yellow with small patches of green, and fall prematurely. Infected buds may fail to open.

Management: 

Once the disease becomes a problem avoid late-season applications of nitrogen fertilizer to limit the production of succulent tissue, which is more susceptible to infection. Avoid overhead watering to help reduce the relative humidity.

Remove and destroy all infected plant parts (leaves, etc.). For infected vegetables and other annuals, remove after harvest as much as possible of the plant and its debris. This decreases the ability of the fungus to survive to next season. Do not compost infected plant debris. Temperatures in the compost often are not hot enough to kill the fungus.

Selectively prune overcrowded plant material to help increase air circulation. This helps reduce relative humidity and infection.

Apply Wettable sulphur (3.0g/l) or Neem Oil (15ml/l) or Flusilazole (0.3 ml/l) or Dinocap (1.0 ml/l) or Hexaconazole (0.5 ml/l) or Difenoconazole (0.6 ml/l) three-four times at 15 days interval

Cercospora leaf spot http://agritech.tnau.ac.in/crop_protection/Cercospora_1.jpeg http://agritech.tnau.ac.in/crop_protection/Cercopspora%20leaf%20spot.jpg
Symptoms: 

Leaf spot can be serious in humid warm areas. It causes leaf spots of various shapes. It grows as a sooty to dark oily (olivaceous) mould on the underside of leaves, but when infection is severe and conditions are very humid it also appears on upper surface of infected leaves. Seriously infected foliage rolls, wilts and falls to the ground.

Management: 

Since the fungus survives on the diseased plant material, removal and destruction and of diseased plant material helps to check the spread of the disease.

Spray Chlorothalonil (2.0g/l ) or Pre packed mixture of Carbendazim+ Mancozeb (2.0 g/l).

The disease is effectively controlled by spraying with Copper Oxychloride (0.3%) or Zineb (0.2%) starting from about a month after sowing and repeating at fortnightly intervals, depending upon the severity of the disease incidence.

Wilt (Rhizoctonia / Fusarium)
Symptoms: 

This disease is caused by fungi, which persist in the soil for a very long time. Initially the plants show temporary wilting symptoms, which becomes permanent and progressive, affecting more vines. The leaves of the affected plants show yellowing, loose turgidity and show drooping symptoms. Eventually, the plant dies. In older plants, leaves wilt suddenly and vascular bundles in the collar region become yellow or brown.

Management: 

Continuous cultivation of bhendi on the same piece of land should be avoided.

Drenching of Bordaux mixture (1%) or Pre packed mixture of Carbendazim+ Mancozeb (2g/l)

Okra Yellow-Vein mosaic Bhendi yellow vein mosaic Image result for Okra Yellow-Vein mosaic
Symptoms: 

The symptoms include alternate green and yellow patches, vein clearing, and vein chlorosis of leaves. The yellow network of veins is very conspicuous, and vein and veinlets are thickened. In severe cases, the chlorosis may extend to the interveinal area and may result in complete yellowing of leaves. Fruits are dwarfed, malformed, and yellow green. The whitefly vector reproduces to significant numbers during the summer season when it transmits the virus between okra plants.

Management: 

Control white flies:

Growing African marigold has been reported to discourage whiteflies.

Tobacco Decoction: Boil 1 kg tobacco dust in 10 liters of water for 30 minutes to attain coffee red colour. Add water to the boiling solution to make 10 litres volume. Cool and filter the decoction using a thin muslin cloth. Add soap @ 2 g/l and dilute to 80 to 100 litres for spray. This preparation is effective against whitefly, aphids, and leafhoppers. Tobacco decoction should not be used frequently as it is toxic to natural enemies.

Neem-based pesticides are reported to control young nymphs, inhibit growth and development of older nymphs, and reduce egg laying by adult whiteflies. Efficacy of neem-based pesticides can be enhanced by adding 0.1 to 0.5% of soft soap.

Yellow sticky traps usually used to monitor the presence of whiteflies for timing of interventions, have also been used as a control method for low density infestations in enclosed environments. Yellow plastic gallon containers mounted upside down on sticks coated with transparent automobile grease or used motor oil. These should be placed in and around the field at about 10 cm above the foliage. Clean and re-oil when traps are covered with flies.

Spray Imidacloprid 200S L (0.3ml/l) or Thiomethoxom 25 WP (0.3g/l) in nursery after 15 days of sowing and after 15 days of planting in main field.

Drench the protrays with Imidacloprid 200SL (0.3ml/l) or Thiomethoxom 25 WP (0.3g/l) one day before transplanting.

Use of resistant cultivars.

Okra enation leaf curl

And Okra fruit distortion mosaic

Symptoms: 

Okra enation leaf curl: On lower surface of leaves we will see a small pin head enations. This enation become warty and rough in structure at later stage. Reduce in leaf size. The stem, lateral branches and leaf petioles become twisted along enation. Leaves appear thick and leathery. In severely infected plants the emerging leaves shows bold enations and curling. And produce few deformed fruits.

The virus is transmitted by white fly.

Management: 

Remove the infected plant and burn them to avoid further spread of disease.

Control white flies:

Growing African marigold has been reported to discourage whiteflies.

Tobacco Decoction: Boil 1 kg tobacco dust in 10 liters of water for 30 minutes to attain coffee red colour. Add water to the boiling solution to make 10 litres volume. Cool and filter the decoction using a thin muslin cloth. Add soap @ 2 g/l and dilute to 80 to 100 litres for spray. This preparation is effective against whitefly, aphids, and leafhoppers. Tobacco decoction should not be used frequently as it is toxic to natural enemies.

Neem-based pesticides are reported to control young nymphs, inhibit growth and development of older nymphs, and reduce egg laying by adult whiteflies. Efficacy of neem-based pesticides can be enhanced by adding 0.1 to 0.5% of soft soap.

Yellow sticky traps usually used to monitor the presence of whiteflies for timing of interventions, have also been used as a control method for low density infestations in enclosed environments. Yellow plastic gallon containers mounted upside down on sticks coated with transparent automobile grease or used motor oil. These should be placed in and around the field at about 10 cm above the foliage. Clean and re-oil when traps are covered with flies.

Spray Imidacloprid 200S L (0.3ml/l) or Thiomethoxam 25 WP (0.3 g/l) in nursery after 15 days of sowing and after 15 days of planting in main field

Drench the protrays with Imidacloprid 200SL (0.3ml/l) or Thiomethoxam 25 WP (0.3g/l) one day before transplanting

Harvesting and yield About 12 tonnes in 120 days.

Integrated pest management practices: (http://www.krishisewa.com/articles/disease-management/233-okra-ipm.html)

  • Sowing of YVMV resistant cultivars viz. parbhani kranti, makhmali, tulsi, Anupama-1, Varsha Uphar, Hisar Unnat, Arka anamika, Hisar Naveen and Sun-40 etc. especially during kharif season of the crop.
  • Seed treatment with imidacloprid 70WS or thiomethoxam 30FS @ 5gm/ kg of seed.
  • Grow maize/sorghum on borders as a barrier to prevent the entry of shoot & fruit borer adults.
  • Set up yellow sticky and delta traps for whiteflies.
  • Erection of bird perches @10/acre in the field for facilitating bird predation.
  • Give two to three sprays of NSKE @ 5% alternating with sprays of pesticides, if needed, against leafhopper, whitefly and mites etc.
  • Install pheromone traps @ 5/ acre for monitoring of Earias vittella moth emergence. Replace the lures after every 30-40 days interval.
  • Release egg parasitoid Trichogramma chilonis @1-1.5 lakh/ ha starting from 30-35 days after sowing, 4-5 times at weekly interval for shoot & fruit borer.
  • Shoot & fruit borer, Earias vittella if crosses ETL (5 % infestation), spray cypermethrin 25 EC @ 200 g a.i/ha or spinosad 45SC @ 0.3 ml/lit or emamectin benzoate 25WG @ 0.4 gm/lit is effective against.
  • Rogue out the YVMV affected plants, if any, from time to time.
  • Periodically remove and destroy the borer affected shoots and fruits.
  • Need based application of chemical pesticides viz. imidacloprid 17.8SL @ 150 ml/ha, cypermethrin 25EC @ 200 g a.i/ha (0.005%), quinalphos 25EC @ 0.05% or propargite 57 EC @ 0.1 % for control of leafhoppers, whiteflies, borers and mites.
  • Removal and destruction of alternate weed hosts near the surrounding field.

http://www.krishisewa.com/images/articles/2013/okraipm12.jpg

Sorghum grown as border in okra

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Natural enemies in okra ecosystem

Note: All recommendations and yields are for one acre area

 

*FYM Enrichment  with Bio-fertilizers and bio-pesticide

 

Well decomposed Farm yard manure (one tonne) is thoroughly mixed Azotobacteror Azospirillum, Phosphate Solubilizing bacteria (PSB),  Trichodermaharzianum or Trichodermaviridae, Pseudomonas fluorescens, Bacillus subtilis, Paecilomyceslilacinus or Pochoniachlamydosporia  each @ 1 kg. This is then moistened by sprinkling water and covered with  wet gunny cloth kept to incubate for  about 3- 4 weeks (15-20 days). For better aeration and decomposition it is advised to give a turn in between at around 10-12 days. This enriched FYM should be mixed with remaining nine tonnes of FYM before applying to the main field.

 

**Neem cake Enrichment  with Bio-fertilizers and bio-pesticide

 

Powdered neem cake (100 kg) with oil content (>10 %) is thoroughly mixed Azotobacteror Azospirillum Phosphate Solubilizing bacteria (PSB),  Trichodermaharzianum or Trichodermaviridae, Pseudomonas fluorescens, Bacillus subtilis, Paecilomyceslilacinus or Pochoniachlamydosporia  each @ 1 kg. This is then moistened by sprinkling water and covered with wet gunny cloth kept to incubate for about 10 days. If it is to be stored for a few more days, for better aeration and decomposition it is advised to give a turn. This enriched neem cake should be applied to the main field along with farm yard manure application at the time of bed preparation for planting. This enrichment is required, if enriched FYM was not used/applied.

 

***Poison baiting: Mix rice bran (10-12 kg/acre) with jaggery (gur) or molasses (2 kg) in the morning. Allow it to ferment till evening.  In the evening, mix this with an insecticide like methomyl or thiodicarb (250 g) and broadcast in main plot. Cutworms get attracted, feed on the fermented poison bait and get killed. Baiting has to be repeated 2 or 3 times more if the incidence of the cut worm or armyworm is high.

 

Baking soda spray: Baking soda is a white soluble compound that has fungicidal properties when used as spray on diseased plants. It also serves as protectant (on plants) from disease-causing pathogens. Mix 1 tbsp of baking soda and 1 tbsp of dormant oil or vegetable oil. Add 4 liters of water and  stir well. Add one tbsp of dish washing liquid soap and stir it again. Fill-in water can or sprinkler and spray. Stir or shake the container from time to time to prevent soda from separating. Repeat application every after 2 weeks. Apply baking soda spray as soon as the symptoms appear. Be sure to include the undersides of the plants’ foliage. Spray in the early morning or late afternoon.

Bordeaux mix: There are many copper compounds that are used as fungicides. The most common is Bordeaux mix which is a combination of copper sulphate and hydrated lime.

Copper sulphate, lime and water in the ratio 1:1:100 are used for preparing one per cent Bordeaux mixture. In order to prepare 100 Litres of mixture one kg of copper sulphate is dissolved in 50 Litres water. In another vessel one kg of fresh quick lime is slaked by sprinkling water and the volume of lime solution is made up to 50 Litres water. The copper sulphate solution is poured into lime solution by stirring the mixture. Both solutions can also be poured into a third vessel with constant stirring. The prepared Bordeaux mixture should be strained through a cloth/strainer before spraying.

Spray plants thoroughly preferably early in the morning, in a dry and sunny day. In this way, the plants have the time to dry and the solution can not penetrate into the leaves’ tissues. Constantly shake the sprayer while in the process of application to prevent the solution from clogging.

 

Cattle-dung and Urine Extract: Mix Cattle-dung (5 kg) and urine (5 liters) thoroughly in 5 liters of water in a container and allow this mixture for 4 days by keeping a lid over the container.  After 4 days, filter and add 100 grams of lime to this solution. Dilute the solution in 80 liters of water, which is sufficient for spraying an acre. Spraying cow dung urine solution prevents eggs laying by the moth, e.g. Helivoerpa and Spodoptera, etc. It is found to give protection against some diseases and the sprayed crop looks green and healthy.

 

Tobacco Decoction: Boil 1 kg tobacco dust in 10 liters of water for 30 minutes to attain coffee red colour. Add water to the boiling solution to make 10 litres volume. Cool and filter the decoction using a thin muslin cloth. Add soap @ 2 g/l and dilute to 80 to 100 litres for spray. This preparation is effective against whitefly, aphids, and leafhoppers. Tobacco decoction should not be used frequently as it is toxic to natural enemies.

 

Precision agriculture, as the name implies, means application of precise and correct amount of inputs like water, fertilizer, pesticides etc. at the correct time to the crop for increasing its productivity and maximizing its yields. Precision agriculture management practices can significantly reduce the amount of nutrient and other crop inputs used while boosting yields. Farmers thus obtain a return on their investment by saving on water, pesticide, and fertilizer costs. Applying the right amount of inputs in the right place and at the right time benefits crops, soils and groundwater, and thus the entire crop cycle. Consequently, precision agriculture has become a cornerstone of sustainable agriculture, since it respects crops, soils and farmers.

 

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