potato post maturity management
TRANSCRIPT
POTATO POST- MATURITY MANAGEMENT
Dieudonné Harahagazwe
Kadahenda, Rwanda
29 April 2016
Integrated Potato Crop Management Course
Outline
•Dehaulming techniques
•Harvest
•Potato storage
I. DEHAULMING TECHNIQUES
(KUNYOMORA)
What is dehaulming?
To cut or remove haulms
(aerial parts of the plant) when
the crop turns yellow in order
to stop the crop growth and
development.
When?
2 weeks before
harvest
Why?
�Tuber growth is stopped in order to produce good
seed size;
�Tubers are protected from late aerial pests and
diseases attack;
�Tubers are protected from being easily wounded
– entry points for diseases - at harvest. The skin
becomes thicker
Methods
2 types: Chemical and Mechanical
�Chemical (herbicides): not accessible and
health hazard
�Mechanical:
� Using a sickle, nife or a machine (mechanization)
� By hand (recommended at small-scale farmer level)
Use of sickle
Rotanda, Mozambique
Kadahenda, Rwanda
Haulms cut and given to livestock by farmers
Problem of using sickles!
Easy top-
down
movement
of
pathogens
Kadahenda, Rwanda
Kadahenda, Rwanda
Best and best practice for dehaulming
Lushoto, Tanzania
Lushoto, Tanzania
Not allowed! To leave haulms in the field.
II. HARVESTING TECHNIQUES
(GUSARURA)
What is harvest?
• Harvest is the process ofgathering mature crops fromthe fields.
• The harvest marks the end of thegrowing season, or the growingcycle for a particular crop
Harvesting Techniques
•Manual
•Semi-mechanized
•Mechanized
Manual harvest
Mechanized Harvest
Western Cape, South Africa
When to harvest?
•At complete crop maturity (around
95% plant death) except in seed
production
•Make a small and quick skin test
•Cultivars have different growth cycles:•Early : up to 90 days after planting (DAP)•Medium: 90 – 120 DAP•Late: over 120 DAP
Common practices:
• All shoots to be removed from the field• Harvest when it is a bit dry and avoid toharvest when the soil is too wet or when itis raining
• Never leave potatoes including rotten onesin the fields as they maintain diseases inthe field
• Sort tubers from the field on the basis oftheir size. For example good seed is about30 – 60 mm diameter
What happens when potatoes are harvested before maturity?
1) Yield loss
2) Increased sensibility to pests and diseases
3) Tuber rottage due to excess of water in the tuber
4) Long dormancy
5) Skin gets off easily
Remember to separate different cultivars
Lichinga, Mozambique
Lichinga,
Mozambique
Seed tubers should
be separated from
ware potatoes
Lichinga, Mozambique Lichinga, Mozambique
III. STORAGE TECHNIQUES
(GUHUNIKA)
Seed storage principles
• Good seed storage is one of the key factors to produce good quality seed
• Good seed: many (at least 3) and vigorous sprouts
• Good storage = Diffused Light Store (DLS)
• DLS:
ohalf light – half dark
oAiry (ventilation)
oShelves (3-4 tubers deep) and never on the
floor
Losses at storage
• On average 30-40% weight loss in 4 months mainly due to :
�Respiration
�Evaporation
�Pest and diseases
• Enabling Factors:
• Tuber maturity: sprouted tubers loose much
more weight than unsprouted ones
• Storage environment (temperature and relative
humidity)
Bad storage!!!
Rotanda, Mozambique
Rotanda, Mozambique
This store is totally dark, not appropriate!
Cold and modern storage
Chimoio, Mozambique
Seed potato in cold store for long-term storage
Chimoio, Mozambique
Small-scale DLS promoted by CIP
DLS for farmers’ association Quality Seed Produced
31
Angonia, Mozambique Angonia, Mozambique
Rotanda, Mozambique
Rotanda, Mozambique
Lushoto, Tanzania
Diga, Ethiopia
Diga, Ethiopia
Acknowledgements
We would like to acknowledge Humidtropics and the CGIAR Fund Donors
for their provision of core and project-specific funding without which this
research could not deliver results that eventually positively impact the lives
of millions of smallholder farmers in tropical Americas, Asia and Africa.
This presentation was made at a training workshop on Integrated Potato Crop
Management organized by the International Potato Center (CIP) for Innovation
Platform (IP) members of Kadahenda, Rwanda.
