Organic Cultivation of Potato 
Organic  potato production generally fits into a planned rotation on an organic  farm. It is possible for a specialist  potato farmer to grow organic potatoes on an organic farm. All other organic  standards will still need to be implemented and the farmer will have to  register with a certification body. It may also be possible to have a single  field in organic crop production, providing it operates a suitable planned  rotation, and organic potatoes can be adequately isolated from any other  potatoes grown on the farm.          Organic potato production is of  interest to many farmers as the crop: Is  in demand from consumers 
           
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Can  be profitable 
           
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Can  be a starting point for a break crop from grass in the rotation 
           
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Requires  cultivation which help control weeds 
           
         
        Challenges of organic potatoes  
                  Organic potato production  has a number of challenges that must be tackled:         
        
        Organic producers  have to rely on alternative approaches rather than artificial fertilizers and  synthetic chemical herbicides and fungicides. 
         
        Cultural practices 
        Soil  
        The soil should be  friable, porous and well drained. The optimum pH range is 4.8 to 5.4. It is a  cool weather crop. Potato is mostly grown as a rainfed crop. It is cultivated  in regions receiving a rainfall of 1200 – 2000 mm per annum.  
        Season and planting 
        Hills 
        
          
            
              Summer  | 
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              March – April  | 
             
            
              Autumn  | 
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              August –    September  | 
             
            
              Irrigated  | 
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              January –    February  | 
             
           
         
        Plains  
        October – November 
         
        Propagation  
         
        Use disease free,  well sprouted seeds weighing 40 – 50 grams. Plant the tubers at 20 cm apart.  Seed rate is 3000 – 3500 kg/ha. 
        Selecting potato varieties 
        In selecting varieties for organic  production there are two simple rules: 
        
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Grow  varieties suited to organic production  
           
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Grow  varieties which best suit the intended market as with all organic produce, grow  what will sell, not what you want to sell 
           
         
        Kufri  Swarna, Kufri Giriraj and Kufri Chipsona- II are suited for organic farming  since they are resistant to blight and nematode. 
        Preparation of field 
        Prepare the land  to fine tilth. In hills provide an inward slope of 1.40 in the terraces.  Provide drainage channel along the inner edge of the terrace. Form ridges and  furrows with a spacing of 45 cm between the ridges either by hand hoe or  ridger. 
        Irrigation 
        Irrigate  the crop 10 days after planting. Subsequently irrigation should be given once  in a week. 
        Manuring 
        
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Green manuring with lupin 60 days before  planting 
           
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Sprinkling horn manure to the soil @ 75 g/ha by dissolving it in 40 litres of water at the time of  land preparation  
           
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Application of well  decomposed farm yard manure @ 50 t/ha at the time of land preparation 
           
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Application of biodynamic  compost @ 5 t/ha at the time of land preparation 
           
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Application of vermicompost  @ 5 t/ha at the time of land preparation 
           
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Application of neem cake @  1250 kg/ha at the time of land preparation 
           
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Application of  biofertilizers like Azospirillum and Phosphobacteria @ 25 kg each/ha at  the time of land preparation 
           
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Spraying cow pat pit @ 5  kg/ha in 100 liters of water on 45th, 60th and 75th  day after planting 
           
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To increase the pH of the  soil, application of dolomite @ 10 tonnes/ha should be done 
           
         
        After cultivation 
        The critical  period of weed competition is up to 60 days and it is essential to keep the  field weed free during that period. Take up the first hoeing on 45th day  without disturbing stolons. Second hoeing and earthing up should be done at 60th  day.           As no herbicides  are permitted, weed control is carried out by:         
        
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Choosing  fields with no major weed problems 
           
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Flame  weeding of weed seedlings before the potato tops emerge – this can be expensive 
           
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Mechanical  weed control just before tops meet between rows 
           
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Limited  hand weeding of any large invasive weeds 
           
         
        Growth regulators 
        
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Foliar spraying of panchagavya @ 3 per  cent at 10 days interval from 1st month after sowing  
           
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Spraying 10% vermiwash 5  times at 15 days interval from one month after sowing 
           
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Foliar spray of horn silica  @ 2.5 g/ha in 50 litres of water on 65th  day after sowing 
           
         
        Plant protection 
        Pests 
        Aphids 
        
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Foliar  spray of 10% nettle leaf extract on 45th, 60th and 75th  day after sowing 
           
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Foliar  spray of 10% garlic- chilli extract on 45th, 60th and 75th  day after sowing 
           
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Foliar  spray of 3% neem oil 
           
         
        Cutworms 
        
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Install  light trap during summer to attract adult moths 
           
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Install  sprinkler irrigation system and irrigate the field in day time to expose the  larvae for predation by birds 
           
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Application  of pyrethrum bait in soil 
           
         
        White grubs 
        
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Summer  ploughing to expose the pupae and adults 
           
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Install  light traps between 7 pm and 9 pm in April – May months 
           
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Hand  pick the adult beetles in the morning 
           
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Hand  pick the 3rd instar grub during July – August 
           
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Application  of Metarrhizium anisopliae @ 20 kg/ha at the time of land preparation 
           
         
        Potato tuber moth 
        
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Avoid  shallow planting of tubers. Plant the tubers at 10 – 15 cm depth 
           
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Install  pheromone traps @ 20 numbers per hectare 
           
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Earth  up at 60 days after planting to avoid potato tuber moth egg laying in the  exposed tubers 
           
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To  control foliar damage, spray 5% neem seed kernel extract  
           
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Keep  pheromone traps in godowns 
           
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In  godowns cover the upper surface of potato with Lantana or Eupatorium branches to repel ovipositing moths 
           
         
        Diseases 
        Potato blight 
        Potato  blight cannot be cured and particularly in an organic situation, avoidance is  definitely the best policy. 
        
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Blight  is not generally a problem with early harvested, early varieties 
           
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Plant  early varieties if suitable/possible 
           
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Plant  healthy, blight free seed 
           
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Select  varieties with high blight resistance 
           
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Listen  for and pay attention to blight warnings 
           
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If  the blight pressure is high apply a permitted fungicide 
           
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Remove  ground creepers which serve as a source of infection 
           
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Spraying  Agni Hotra ash (200 g Agni Hotra ash soaked in 1 liter cow urine for 15 days  and diluted in 10 litres of water before spraying) 3 times at one month  interval from one month after planting 
           
         
        Brown rot 
        
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Select  disease free seeds 
           
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Give  proper drainage facilities 
           
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Remove  and destroy the affected plants 
           
         
        Virus diseases 
        
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Use  virus free potato tubers 
           
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Rogue  the virus affected plants regularly 
           
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Control  the aphid vectors by spraying 10% nettle leaf extract on 45th, 60th  and 75th day after planting 
           
         
        Nematodes 
        
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Avoid  growing potato year after year in the same field 
           
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Follow  rotation of crop with vegetables and green manure 
           
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For  cyst nematode, a resistant variety called Kufri Swarna can be grown 
           
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Application  of Pseudomonas fluorescens @ 10 kg/ha can be done 
           
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Sow  mustard as intercrop at the time of potato planting and harvest the mustard  greens on 45th day for the control of potato cyst nematode 
           
         
        Haulm removal 
         
        Only physical  means of haulm removal are permitted. These include: 
          a) Flailing (haulm chopping) 
          b) Haulm pulling 
          c) Flaming  
          Chemical methods of desiccation or  application of sulphuric acid are not permitted. 
   
  Storage  
         
        Normal methods of storage apply to  organic potatoes however, 
        
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Adequate  isolation from non organic potatoes will be required to avoid substitution or  contamination. This may require visibly identifiable varieties only. 
           
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Sprout  suppressants and fungicides are not permitted in store. 
           
         
        Yield 
      15 – 20 t/ha in duration of 120 days.  |