Production and post-production practices contributing to

qualitative and quantitative losses in Africa

John Manful

22nd to 25th November 2011, Cotonou, Benin

Introduction

• Rice is the most important food crop in the world, providing over 21% of the calorific needs of the world’s population.

• In sub-Saharan Africa, about 80% of the rice production is in the hands of small farmers.

• About 75% of the land area under rice is not irrigated.

• Rice imports into sub-Saharan Africa continue to outstrip local production.

• Locally produced rice is not competitive in terms of “price-quality” when compared with imported rice.

• Subsequently, the different actors in the rice value chain are not receiving enough compensation for their produce and this has obvious negative implications for their livelihoods.

Post-harvest losses in rice

• Considerable losses occur at various stages along the rice value chain.

• Post-harvest losses in rice can be classified into two main categories:

- Quantitative losses and

- Qualitative losses.

Quantitative losses

• Although quantitative post-harvest losses are significant in rice production, they are not as high as in fruits, vegetables, roots, tubers, fish and meat products.

• Quantitative losses in sub-Saharan Africa are estimated to be between 10 to 22% with an average of about 15%

Quantitative losses

• May occur as a result of:

• Action of birds and rodents in the field

• Lodging and shattering at maturity

• Spillage during threshing

• Incomplete threshing

• Breakages and losses during milling

• Action of insects and other pests in storage

Qualitative losses

• This refers to the loss in the market value of the rice as a result of compromises in the physical quality due to inappropriate practices along the value chain.

• Qualitative losses are very high Africa and could be as high as 50% in some cases.

Qualitative losses

• Several factors contribute to qualitative losses of rice produced in sub-Saharan Africa and these include:

• Delayed harvesting• Handling after harvest• Threshing methods• Drying• Parboiling methods• Milling• Packaging

Delayed harvesting

• Reasons for delaying harvest include:- Not enough labour available at harvest time.- The right machinery not available at harvest

time (There is usually nothing in between combine harvesters on one hand and the sickle and cutlass on the other)

- Some farmers think that paddy is a durable product so the harvesting can wait while he harvests more perishable crops

Implications for quality

• Delayed harvest may result in plants lodging and some shattering if variety is susceptible.

• Harvesting over-dried rice leads to increased losses due to scattering.

• Any attempt to recover lodged and shattered crop comes with gathering stones and other undesirable materials.

• Lodged crops may pick up moisture from the soil and lead to mouldiness in the grains.

• Lodged crops are more likely to be contaminated with aflatoxins.

• Delayed harvested crops over-dry resulting in cracked grains leading to high brokens on milling and a low milling recovery.

Handling after harvest

• Usually paddy is heaped on the farm after harvest.

• Heaps of paddy may be left in the field for prolonged periods prior to threshing.

Implications for quality

- Heat and moisture build up in the heaped paddy.

- This can lead to mouldiness and grain discolouration.

- Aflatoxin contamination is high particularly in humid environments.

- The paddy is more susceptible to pest and insect attack.

- Some of the grains begin to germinate.

Threshing methods

- Threshing is usually manually carried out.

- Manual threshing methods result in spillage of grains.

- Scattered grains are usually manually recovered and this comes with stones and mud.

- Mechanical threshing of over-dried paddy results in cracked grains.

Drying

- Drying after harvest is usually done in open sunshine.

- Drying surfaces include bare clay floors or cemented floors with cracks.

- Drying may also be done rapidly in the sun with no “rest periods” for moisture gradient equalization resulting in the creation or aggravation of existing cracks in the grains.

Parboiling

- Parboiling is known to reduce breakage and improve milling recovery yields.

- However, inappropriate parboiling techniques result in even greater brokens and poorer quality of the product.

- To obtain good parboiling results,• Paddy should be cleaned and washed before

parboiling with the best quality water available.• Soaking temperatures should be over 70°C and

steaming times over 10minutes to ensure optimum quality

Milling

- Most rice mills in West Africa are the Engelberg type and these usually do not give good results.

- Most of the mill operators have also not received the correct training on the operation and maintenance of the equipment.

Marketing

- Milled rice is usually not graded and packaging is poorly done in West Africa.

- This results in low and uncompetitive prices being offered for locally produced rice as compared to imported rice.

Merci

Thank you