Sweet potato planting

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Sweet potato planting
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Land preparation

• Good land preparation will
• enhance good sprouting and crop establishment
• reduces weed competition

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Land preparation . cont

• Precautions
• Avoid soil contaminated with diseases nematodes,
  or weevils. 4-yr rotations are recommended.
• avoid replanting on the same plot.
• the new plot should not be planted next to old or
  existing plot. Use 100 m barrier between plots.

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Land preparation . cont

1. soil rich in organic matter is not recommended
   cause rough, cracked, oversize root and promote
   veg. growth.
2. Sandy loam is preferred. Not clay soils.
3. Planting on ridge or mound is recommended good
   drainage and easy harvesting.

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Land selection

• Can grow in almost any soil
• Best on deep and moderate fertile soils.
• Sandy loam with well drained.
• Avoid clay soil irregular size and shape of
  
• tubers.
• Mounds are preferred for good drainage and
  easy
• harvesting

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Land selection

• Planting sweet potato in
• Rich, heavy soils produce high yields of low
  quality tubers and
• poor, light sandy soils generally produce low
  yields, but of high quality tubers.

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Planting Materials

• Tuber slips
• The sprouts from the root. To maximize the
  number of cuttings, remove the tips of the
  sprouts when they are about 20 cm long, to
  promote branching.
• Soaking tubers in
• sodium hypochlorite
• for 5-20 min.

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Planting Materials

• Tuber slips . cont
• The sprouts from the root.

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Planting Materials

• Stems/vines
• Select young plant of 2-3 months old, will
  produce higher yield.
• Plants free from pests and diseases.

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Planting Materials

• Stems/vines cont
• Generally the apical portion of the vine is
  better than the middle or basal portions. This
  portion is less likely to carry sweet potato
  weevils and fungal pathogens,
• and has been found to
• establish faster than
• other portions.

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Planting Materials

• Stems/vines cont
• Length of cutting is less important than the
  number of nodes. Typical size is 20-40 cm, with
  5-8 nodes.
• Usually one-third to two-thirds of the cutting
  is buried. A minimum of 2-3 nodes, but up to
  about 8 nodes, is placed under the soil.

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Planting Materials

• Stems/vines cont
• Cuttings infected with P D can be treated
  with
• Leaf scab disease soak cutting in Mancozeb
  for 15 min.
• Weevils soak in diazinon for
• 20 min.

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Plant spacing

• A common spacing is 30 cm between plants and 1
  to 1.5m between rows (12,500 to 14,500 slips per
  acre).

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Planting Materials
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Questions?
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Weed control

• Good land preparation.
• Use contact herbicide e.g. Gramoxone,
  glyphosate. Before planting (15-30 days)
• Critical within 1-2 months.

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Fertilizers

• Nitrogen (N)
• Has a strong influence on the distribution of
  dry matter.
• Affecting root growth relative to shoot
  growth.
• N deficient causes low protein content in
  tubers.

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Fertilizers

• Nitrogen (N) . cont
• The rate
• 30-90 kg N/ha.

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Fertilizers

• Phosphorus (P)
• The rate
• 100 kg P/ha.
• Potassium (K) has greater effect on tuber
• yield than N and P
• The rate
• 100 kg K/ha

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Fertilizers

• When to fertilize?
• Half the fertilizer can be applied before
  planting, either directly under the ridge or a
  near the ridge.
• Make the first application of fertilizer 10-14
  days before planting time.
• The second half of the fertilizer can be
  applied as a side-dressing after plants have
  begun new growth.

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Questions?
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Harvesting

• Need to harvest when
• 1. tubers at the right size for market.
• This depend on plant spacing and env.
• 2. Usually 130-170 days from planting are
  needed to give highest yields

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Harvesting

• If left in the field, plant will
• 1. continue to grow, the tuber will start
  regeneration phase and initiate new shoot
  growth.
• 2. Tubers will crack and become fibrous.
• 3. Weevil outbreak and rat damage.

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Questions?
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Thank you