Potato (Solanaum (tuberosum)

 Varieties currently being grown at the Institute are:

 Montclare

·         late maturity

·         produces large to extra-large tuber with deep eyes

·         white skinned and white fleshed

·         yield up to 60 t/ha

·         resistant to both early and late blight

BP1

·         medium to early maturity variety (14 – 15 weeks)

·         white skinned and white fleshed, oval shape with shallow eyes

·         yield up to 30 t/ha depending on summer or winter

·         resistant to late blight

 Pimpernel

·         mainly used by the processing industry

·         late maturity 17 – 19 weeks

·         red skinned, yellow fleshed tubers

·         tubers are oval, small to medium with deep eyes

·         yield 20t/ha

 Amethyst

• late maturing variety (17-19 weeks)
• white skinned and white fleshed
• flat oval with shallow eyes and rough skin
• perform well in all regions
• yield between 35 – 60 t/ha

Garnet

• late maturing variety (17 – 19 weeks)
• Round medium sized tubers
• White skinned and yellow fleshed
• Suitable for processing – good crisping quality
• Good yielder up to 26 t/ha

 Jasper

·         Vigorous growing, late maturing variety

·         Late blight tolerant

·         Frost tolerant

·         White skinned and white fleshed round to oval tubers

·         Yield 30t/ha

 Diamond

• Resembles BP1 in most characteristics but give a high yield reaching about 60 t/ha

Planting Program

 Summer crop – f rom October, normally rain fed, however lifting may be difficult due to high rainfall.

 First winter crop – Feb – April plantings and matures before frosts

 Second winter crop – planted late July – Aug after frost risk has passed, fairly free of blight

 Crop management practices

  PEPPER

 Green and red peppers are most common on the market. They can be grown in the open field or in the tunnels on raised beds or on the flat. Pepper training is done to reduce bushness of the plant and promote good pod distribution and fruit quality

 Raising seedling of tomatoes, pepper and eggplants is done in speedling trays.

1. Seeds are sown in the cells filled with media (pine bark, manure and sawdust) and Ammonium Nitrate, SSP, MOP are sprayed on the plants after emergence.
2. Germination of seedling informally take 7 – 10 days Seedlings normally take 6 – 8 weeks before they are ready for transplanting
3. Transplanting is done when seedlings are pencil thick 15- 20 cm tall and have 3 – 5 true leaves

Fungicides such as Ridomil should be used to control damping off in the nursery

1. Tomato seedlings in speedling trays                           Tomato seedlings transplanted

Planting

The plants can be grown in the open field or in the tunnels.

1. Recommended spacing is between 30 – 50 cm x 0.9 – 1.5 m between rows which results in a population of 13 333 plants/ha.
2. Carefully remove seedling from the trays taking care not to break them and gently the plants in the holes covering with soil

 Fertilizer

Trellising

 Trellising improves fruit quality.

• Single stake – place stake alongside and the plant to stake at intervals
• Single wire – tie twine between wires at plant station and train plants up twine.  Commonly used in the tunnel

 Irrigation

Irrigate immediately after planting and every 5 – 6 days thereafter

• Drip irrigation

Drip irrigation enable water to be applied close to plants, only roots grow wet and thus eliminate fungal diseases. Enables more frequent applications thereby providing very favourable high moisture level where plants flourish.  Water is efficiently used and it also enables fertilizer application

Pest and diseases

 It is important to obtain treated seed form reliable sources

• Whitefly, heliothis ball worm are most prevalent – control with conldorl, soap spray (whitefly)
• Blight (early and late) rotate fungicides both to control and prevent the disease e.g. Ridomil, Dithane M45, Bravo, Euthane and any available on the market.

Hygiene

 In the field or tunnel

·         Burn and discard infected plants or crop residue formalin or any disinfectant

·         Equipment should be sterilized with 2% formalin or any disinfectant

·         Forbid smoking or snuff taking

Cultural Practices

·         Avoid water logging conditions

·         Follow correct fertilizer, spray and irrigation schedule

 Site selection of nursery area

Factors considered are:-

·         Soil drainage

·         Frost free site – green house in cold areas like Marondera and Eastern Highlands

·         Permanent water supply

Nursery media characteristics

·         Good aeration for gaseous exchange

·         Good moisture retention capacity - Inclusion of pine bark is essential

·         Must be free form diseases

·         Contain adequate nutrients to support plant growth

 Types of Nursery Media

·         Pine bark

·         Vlei soil

·         Saw dust

·         Sand

·         Mixture of all

Media used at HRC

o   4 parts pine bark, 2 parts compost, 2 parts vlei soil all mixed together

  Preparation of Mini stem cutting

 1.    The stem is cut to 15 cm length

reduce loss of water through evapo-transpiration.

 Shooting and Establishment

1.    The cutting develops shoots after 7 days to 10 days after planting

Management of Nursery

·         Watering

·         Weed control

·         Pest control

·         Disease control

·         Top dressing

·         Labeling

·         Ratooning

What is the greatest constraint in sweet potato production in Zimbabwe?

According to HRI’s observation it is inadequate high quality planting material (viral-free) and technical know-how.

How can this constrain be alleviated?

·         More funds should be channeled towards resuscitation of tissue culture laboratories

·         Prominence should be given to science and technology

·         Farmer training should be enhanced through fostering formal farmer-extensionist-researcher linkages.

Processing and Product Development

 Main Use

·         Utilized primarily as human food stuff- rich in carbohydrates

·         Prepared through boiling, frying and roasting

·         In Malawi they are roasted and pounded together to produce futali

·         In USA about 60% to 70% of sweet potato is utilized for human food, eaten fresh, canned, frozen, or dehydrated and used in a variety of products such as baby foods.

 Processing of Sweet Potato

 By Products

During each processing stage some products are formed which are:-

·         Animal feed – the outer skins which have been peeled are used as a high source of carbohydrate feeding stuff for cattle, pigs, and poultry

·         Chips – produced from sliced peeled tubers which are then roasted fried with cooking oil.

·         Starchy – produced after grating the peeled tubers, water added to the stuff which then forms a milk white substance.

 The waste is extracted out and the liquid formed is allowed to settle down so that clear water stuff floats on top of the soil stuff formed at the bottom which is allowed to dry to form starch.

 Uses of starch

Used in the textile industries, paper production, food manufacturing and preparation of adhesive and glucose.

·         Flour – the peeled tubers are dried and milled into flour which can be used as substitute to wheat flour in bread and cake baking

·         Drink – during starch production the clear water formed is tapped off and mixed with preservatives and flavors to form a drink.

·         Beer – the clear water extracted out during starch production can be fermented to produce beer.

 Potato (Solanaum (tuberosum)

 Varieties currently being grown at the Institute are:

 Montclare

·         late maturity

·         produces large to extra-large tuber with deep eyes

·         white skinned and white fleshed

·         yield up to 60 t/ha

·         resistant to both early and late blight

BP1

·         medium to early maturity variety (14 – 15 weeks)

·         white skinned and white fleshed, oval shape with shallow eyes

·         yield up to 30 t/ha depending on summer or winter

·         resistant to late blight

 Pimpernel

·         mainly used by the processing industry

·         late maturity 17 – 19 weeks

·         red skinned, yellow fleshed tubers

·         tubers are oval, small to medium with deep eyes

·         yield 20t/ha

 Amethyst

• late maturing variety (17-19 weeks)
• white skinned and white fleshed
• flat oval with shallow eyes and rough skin
• perform well in all regions
• yield between 35 – 60 t/ha

Garnet

• late maturing variety (17 – 19 weeks)
• Round medium sized tubers
• White skinned and yellow fleshed
• Suitable for processing – good crisping quality
• Good yielder up to 26 t/ha

Jasper

·         Vigorous growing, late maturing variety

·         Late blight tolerant

·         Frost tolerant

·         White skinned and white fleshed round to oval tubers

·         Yield 30t/ha

Diamond

• Resembles BP1 in most characteristics but give a high yield reaching about 60 t/ha

Planting Program

Summer crop – f rom October, normally rain fed, however lifting may be difficult due to high rainfall.

First winter crop – Feb – April plantings and matures before frosts

Second winter crop – planted late July – Aug after frost risk has passed, fairly free of blight

Crop management practices

  PEPPER

 Green and red peppers are most common on the market. They can be grown in the open field or in the tunnels on raised beds or on the flat. Pepper training is done to reduce bushness of the plant and promote good pod distribution and fruit quality

Raising seedling of tomatoes, pepper and eggplants is done in speedling trays.

1. Seeds are sown in the cells filled with media (pine bark, manure and sawdust) and Ammonium Nitrate, SSP, MOP are sprayed on the plants after emergence.
2. Germination of seedling informally take 7 – 10 days Seedlings normally take 6 – 8 weeks before they are ready for transplanting
3. Transplanting is done when seedlings are pencil thick 15- 20 cm tall and have 3 – 5 true leaves
4. Fungicides such as Ridomil should be used to control damping off in the nursery
5. 

6. Tomato seedlings in speedling trays                                            Tomato seedlings transplanted

   
   Planting

   The plants can be grown in the open field or in the tunnels.

   1. Recommended spacing is between 30 – 50 cm x 0.9 – 1.5 m between rows which results in a population of 13 333 plants/ha.
   2. Carefully remove seedling from the trays taking care not to break them and gently the plants in the holes covering with soil

   Fertilizer

   Trellising

   Trellising improves fruit quality.

   • Single stake – place stake alongside and the plant to stake at intervals
   • Single wire – tie twine between wires at plant station and train plants up twine.  Commonly used in the tunnel

   Irrigation

   Irrigate immediately after planting and every 5 – 6 days thereafter

   • Drip irrigation

   Drip irrigation enable water to be applied close to plants, only roots grow wet and thus eliminate fungal diseases. Enables more frequent applications thereby providing very favourable high moisture level where plants flourish.  Water is efficiently used and it also enables fertilizer application

    Pest and diseases

    It is important to obtain treated seed form reliable sources

   • Whitefly, heliothis ball worm are most prevalent – control with conldorl, soap spray (whitefly)
   • Blight (early and late) rotate fungicides both to control and prevent the disease e.g. Ridomil, Dithane M45, Bravo, Euthane and any available on the market.

   Hygiene

   In the field or tunnel

   ·         Burn and discard infected plants or crop residue formalin or any disinfectant

   ·         Equipment should be sterilized with 2% formalin or any disinfectant

   ·         Forbid smoking or snuff taking

   Cultural Practices

   ·         Avoid water logging conditions

   ·         Follow correct fertilizer, spray and irrigation schedule

   Site selection of nursery area

   Factors considered are:-

   ·         Soil drainage

   ·         Frost free site – green house in cold areas like Marondera and Eastern Highlands

   ·         Permanent water supply

   Nursery media characteristics

   ·         Good aeration for gaseous exchange

   ·         Good moisture retention capacity - Inclusion of pine bark is essential

   ·         Must be free form diseases

   ·         Contain adequate nutrients to support plant growth

   Types of Nursery Media

   ·         Pine bark

   ·         Vlei soil

   ·         Saw dust

   ·         Sand

   ·         Mixture of all

   Media used at HRC

   Preparation of Mini stem cutting

   1. 1.    The stem is cut to 15 cm length

   reduce loss of water through evapo-transpiration.

   Shooting and Establishment

   Management of Nursery

   ·         Watering

   ·         Weed control

   ·         Pest control

   ·         Disease control

   ·         Top dressing

   ·         Labeling

   ·         Ratooning

   
   What is the greatest constraint in sweet potato production in Zimbabwe?

   According to HRI’s observation it is inadequate high quality planting material (viral-free) and technical know-how.

          How can this constrain be alleviated?

7. ·         More funds should be channeled towards resuscitation of tissue culture laboratories

   ·         Prominence should be given to science and technology

   ·         Farmer training should be enhanced through fostering formal farmer-extensionist-researcher linkages.

   Processing and Product Development

   o   Primary products are:

   Main Use

   ·         Utilized primarily as human food stuff- rich in carbohydrates

   ·         Prepared through boiling, frying and roasting

   ·         In Malawi they are roasted and pounded together to produce futali

   ·         In USA about 60% to 70% of sweet potato is utilized for human food, eaten fresh, canned, frozen, or dehydrated and used in a variety of products such as baby foods.

   Processing of Sweet Potato

   By Products

   During each processing stage some products are formed which are:-

   ·         Animal feed – the outer skins which have been peeled are used as a high source of carbohydrate feeding stuff for cattle, pigs, and poultry

   ·         Chips – produced from sliced peeled tubers which are then roasted fried with cooking oil.

   ·         Starchy – produced after grating the peeled tubers, water added to the stuff which then forms a milk white substance.

   The waste is extracted out and the liquid formed is allowed to settle down so that clear water stuff floats on top of the soil stuff formed at the bottom which is allowed to dry to form starch.

   Uses of starch

   Used in the textile industries, paper production, food manufacturing and preparation of adhesive and glucose.

   ·         Flour – the peeled tubers are dried and milled into flour which can be used as substitute to wheat flour in bread and cake baking

   ·         Drink – during starch production the clear water formed is tapped off and mixed with preservatives and flavors to form a drink.

   ·         Beer – the clear water extracted out during starch production can be fermented to produce beer