HORDI Crop – Potato

HORDI - LOGO
<< Crop Page    

Potato

Solanum tuberosum

Potato is belong to solanacea family. It was introduced to Sri Lanka by Samuel Baker in 1850. Large Scale cultivation of potato was started by Department of Agriculture in Rahangala farm but it was failed due to bacterial wilt. Farmers multiply potato seeds on land in higher elevation for producing seeds for the major cultivation season (Yala season).

Released Varieties

Climate requirements/ Areas suitable for cultivation

Tuber initiation of potato requires low soil temperature less than 24 oC. Day and night temperature difference should have more than 10 oC for successful crop. Potato grows well in up country area whereas heat tolerance varieties can be grown in dry areas such as Jaffna and Kalpitiya. 

Soil

Well drain soil with more organic matter is required. Suitable pH range is 5.5-6.6.

Seed requirement

2000 kg tubers /ha

Nursery Management

N/A

Land preparation

Plough soil to the depth of 30 cm and add lime if pH is low.

Planting

Potato tubers can be planted in ridges or raised beds. Soil earthing up is carried out 30 days after planting

Spacing

60 x 25 cm

Fertilizer

For up lands of Nuwara Eliya and Badulla districts and calcic red latosols soil of Jaffna district;

Times for applyUrea  kg/haTSP kg/haMOP kg/ha
Basal fertilizer55270125
Top dressing (2 weeks after planting) 110
Top dressing (3-4 weeks after planting)165125

For rice based cropping system of Nuwara Eliya and Badulla districts;

Times for applyUrea  kg/haTSP kg/haMOP kg/ha
Basal fertilizer5527085
Top dressing (2 weeks after planting) 110
Top dressing (3-4 weeks after planting)16585

For regosols of Kalpitiya;

Times for applyUrea  kg/haTSP kg/haMOP kg/ha
Basal fertilizer270
Top dressing (2 weeks after planting) 6550
Top dressing (4, 6 & 8 weeks after planting)9070

Water supply

Tuberization and tuber bulking stages are critical for water supply. High yielding crop required about 70 % available water. Sprinkler or drip irrigation methods are more suitable than the furrow irrigation.

Weed Control

Pre-emergent herbicide: metribuzine can be spray to control weeds. Weeds also control by intercultural operations at 2 and 4 weeks after planting.

Pest Management

Become serious pest during the dry period Damage symptoms Adult punchers leave for both feeding and oviposition. This may cause a spotted appearance on foliage. Larvae make irregular mine and result drying and withering of leaves. Damage potato plants succumb to secondary infection by late blight.
Management
  • Regular field inspection
  • Yellow colour sticky trap
  • Covering crops with suitable material prevent mitigating flies
  • Removal of other host plants surrounds the crop field
  • Removal and distraction of infected plant material
  • Augment ecto-parasitoid Diglyphus isaea
  • Encourage naturally found parasitoids Hemiptarsenus semibiclavas and Opius spp
Chemical control
  • Azadiractin 1% EC at the rate of 16ml/16 l of water
  • Abamectin 18g/l EC at the rate of 9.6 ml/16 l of water
  • Neem seed water extract at the rate of 640g/16 l of water
Most economic damage occurs to potato tubers in storage conditions Damage Symptoms In Field Larvae destroy the crop by mining leaves or boring in to petioles and terminal shoots. This cause wilting and reduce photosynthesis.After tuberization the larvae enter into the tubers and feed on them. Infested tubers are further exposed to secondary infections which lead to rotting. In stores Adult moth infests tubers by depositing eggs near the tuber eyes. Larvae cause irregular galleries and tunnels deep inside or just below the skin of the tubers. Tunnel can be detected by excreta appearing black at the entrance. Larval damage results both weight and quality loss of potato tubers.
Management In field
  • Regular monitoring
  • Healthy seed tubers to be planted slightly deeper
  • Proper earthing up to avoid exposing tubers
  • Crop rotation
  • Discourage growing of alternate host plants
  • Proper irrigation to prevent soil cracks and soil spaces are
  • Removing all tubers from fields at harvesting
  • Destruction of residues and maintain proper field sanitation
Chemical control
  • Chlorantraniliprole20%+Thiamethoxam 20%WG at the rate of 5g per 16l of water
In stores
  • Reject seed lots from fields or storage that had been infested with PTM
  • Maintain proper Storage sanitation
  • Tubers must be undamaged and free from soil or other residues
  • Tubers should be kept at cold store
  • Application of seed treatments- Thiocyclam (Hydrogen Oxalate) 50% SP-40g/100Kg of seeds
Chemical control
  • Pirimiphose methyl 500g/l EC at the rate of 64 ml per 16 l of water
  • Acetamiprid 200g/l SP at the rate of 16 ml per 16 l of water
  • Novaluron 100g/l EC at the rate of 16 ml per 16 l of water
Damage symptoms Habitually they are nocturnal. Early instars make round holes in leaves. Later, the shoots are damaged close to the ground, often cut the whole plant at the base, during emergence. Cut several plants in a single night and pulling the plant stem belowground.  Cut plants show wilting during day time. Formed unsightly holes in the potato tubers
Management
  • Regular monitoring
  • Hand collecting and destroying
  • Weed management
  • Proper field sanitation
  • Plough the soil deeply to bring the larvae and pupa to the surface of the soil
  • Encourage predatory birds to preying the worms during tillage operation
Chemical control
  • Profenophos 500 g/l EC at the rate of 32 ml per 16 l of water
  • Etofenprox 100g/l EC at the rate of 24 ml per 16 l of water

Damage Symptoms

Nematode remove nutrient from the roots and diminish supply of nutrient and water to the stems and leaves by injuring the roots and stunning their growth. Moderately infested plants normally have reduced tuber size. Heavily infested plants develop poorly and show yellowing of plants.  Temperature become wormer, wilting of plants occurs.

Management

There are three basic challenges in managing PCN.

  • Keeping potato land free of PCN
  • Preventing lightly infested land from becoming heavily infested
  • Bring high populations back to manageable levels

Follow the instruction below if the land is not infested

  • Use certified seeds from DOA
  • Avoid use of seed potatoes, soil and agriculture implements from infested land
  • Treat the seed with 1% Sodium Hypochlorite solution for 25-30 minutes before planting
  • Soil testing before planting
  • Use interval between potato crops
  • Preventing lightly infested land from becoming heavily infested
  • Crop rotation
  • Fallowing
  • Avoid cultivation potato or solanaceous crops two or three seasons
  • Use of resistant varieties
  • Repeated sampling and determine the whether management is working
  • Bring high populations back to manageable levels
  • Apply Calcium hypochlorite at the rate of 70Kg/ha

Other than that educated farmers on the followings are more important

  • Importance of PCN as a potato pest
  • Easy method to detect PCN
  • Control methods
  • Prevent spread of PCN to new land
Aphids are vectors of several viruses. Direct feeding damage is not significant. Damage symptoms They occur in large numbers on the tender shoots and lower leaf surfaces and suck the plant sap. Severe aphid infestations cause young leaves to curl and become deformed. Produce honeydew, which leads to the development of sooty mould. Transmit virus diseases.
Management
  • Monitoring aphids’ population visually or placing yellow colour water trap.
  • Weed control in crop fields to reduce the availability of alternate host plants
  • Protect the predators and parasitoids by avoiding the use of broad-spectrum pesticides unnecessarily
Chemical control
  • Thiamethoxam 25% WG at the rate of 5g per 16 l of water
  • Imidacloprid 70%WG at the rate of 2g per 16 l of water
  • Thiocyclam (Hydrogen Oxalate) 50% SP at the rate of 40g per 16 l of water
  • Chlorantraniliprole 20% + Thiamethoxam 20% WG at the rate of 5g per 16 l of water
  • Buprofezin 25% SC at the rate of 45ml per 16 l of water
  • Azadirachtine 5%EC at the rate of 16ml per 16 l of water

Damage symptoms

Thrips feed on potato leaves by rasping plant cells and sucking out its contents. Feeding on leaves caused deformities of the crop. Commonly found on the underside of leaves. Distinctive silvery or bronze scarring on the surfaces of the stems or leaves where the thrips feed

Management

  • Weed control in crop fields to reduce the availability of alternate host plants
  • Protect the predators and parasitoids by avoiding the use of broad-spectrum pesticides unnecessarily
  • Planting at correct time
  • Crop rotation

Chemical control

  • Thiamethoxam 25% WG at the rate of 5g per 16 l of water
  • Imidacloprid 70%WG at the rate of 2g per 16 l of water
  • Thiocyclam (Hydrogen Oxalate) 50% SP at the rate of 40g per 16 l of water
  • Chlorantraniliprole 20% + Thiamethoxam 20% WG at the rate of 5g per 16 l of water
  • Buprofezin 25% SC at the rate of 45ml per 16 l of water
  • Azadirachtine 5%EC at the rate of 16ml per 16 l of water

Damage symptoms

The adults and nymphs suck the plant sap and reduce the vigor of the plant. In severe infestations, the leaves turn yellow and drop off. When the populations are high they secrete large quantities of honeydew, which favors the growth of sooty mould on leaf surfaces and reduces the photosynthetic efficiency of the plants.

Management

  • Maintain a high standard of weed control in crop fields to reduce the availability of alternate host plants
  • Use yellow/blue sticky traps (Hang the traps slightly above or at the canopy level for better trapping)
  • Spraying water – useful in dislodging adults

Chemical control

  • Thiocyclam (Hydrogen Oxalate) 50% SP at the rate of 40g per 16 l of water
  • Chlorantraniliprole 20% + Thiamethoxam 20% WG at the rate of 5g per 16 l of water
  • Buprofezin 25% SC at the rate of 45ml per 16 l of water
  • Azadirachtine 5%EC at the rate of 16ml per 16 l of water

These pests are recorded as occasional pest.

Damage symptoms

The larvae damage roots, stems and tubers and reduce the market quality of tubers.

Management

  • Plough the soil deeply to bring grubs to the surface
  • Encourage predatory birds to preying the worms during tillage operation
  • Crop rotation
  • Increase field sanitation
  • Application of properly decomposed FYM(Farm Yard Manure) /compost at recommended dose

Damage symptoms

Create irregular holes with smooth edges on leaves and destroy tender leaves. Damage is common during rainy weather or an abundance of weed growth.

Management

  • Eliminate place where can shelter during day time
  • Regular practice of trapping and removing snails
  • Removing debris and manage field sanitations
  • Proper weed management
  • Regular field infection and hand collection
  • Encourage predatory birds by enhancing natural habitats

Chemical control

  • Metaldehyde 5% GR at the rate of 10-40 Kg/ha

Disease Management

  • Crop rotation/Fallowing
  • Start cultivation at correct time
  • Use resistant varieties – Carlous
  • Use disease free tubers
  • Application of Fungicides – Mancozeb, Maneb, Metalaxyl, Fluazinam
  • Crop rotation
  • Application of fungicides – Mancozeb, Maneb
  • Use disease free tubers
  • Maintain soil pH 5.0- 5.2
  • Maintain soil water level
  • Crop rotation
  • Use disease free tubers
  • Crop rotation/Fallowing
  • Use disease free tubers
  • Crop rotation/fallowing – at least three years
  • Improve drainage in the fields
  • Use disease free tubers
  • Crop rotation
  • Control vectors – aphids
  • Regular monitoring the field
  • Remove and destroy infected plants

Harvesting

Haulms should be removed 2 weeks before harvesting for maturing tubers

Yield

20-25 t/ha