Topic: Control of the Spread of the GGB Through Improved Maize
Drying Practices
Duration: Up to 4 hours
Objectives:
By the end of this session, the participants should:
(i) appreciate the need to dry maize as thoroughly as possibleii) know common drying methods
iii) know the common indicators of identifying dry maize
iv) be able to evaluate the merits and demerits of the maize-drying techniques and structures that they currently use
v) take decisions to implement improved maize-drying techniques and structures.
Target Group:
- Subject Matter Specialists (SMS's)
- Technical Assistants (TA's)
- Local leaders
- Farmers
Training Materials:
i) wooden models of any maize-drying structures commonly used in the area, e.g. cribs, trays, lofts ("dari"), mats, etc.ii) sample of maize attacked by fungi, insects or which is germinating
iii) samples of dehusked maize cobs
iv) paraffin candles or lantern with paraffin and matches
v) hand-operated blower or fan
vi) small brush or broom
NB:
This session may either be conducted in a classroom using the above equipment or may be demonstrated on farms if suitable ones can be located nearby.
Process:
a) The trainer should ask the participants to give reasons why they dry maize. The following reasons should be mentioned:
15 minutes
To increase the storage life and to maintain a high quality of produce through:i) reduction in growth of fungiii) reduction in storage insect infestation, such as the GGB
iii) reduction in respiration of the kernel
iv) prevention of germination while the kernel/seed retains its germination potential.
* The trainer should explain, as much as possible with examples, that points i) and ii) above involve lives of predators/pests which, like human life, need water to survive. So, depriving them of water means denying them a chance to live.
* * It should be explained that points iii) and iv) above have to do with the life of the kernel/seed itself which, like we humans, cannot continue to live without water.
b) The participants should, at this stage, be shown the maize which has been rendered either harmful or totally useless for human consumption through attacks of fungi, insects, etc. or through germination.
10 minutes
c) The trainer should then give a short talk on the characteristics of a good maize-drying system. The following points need to be emphasized:i) The system should - be effective and efficient, i.e. the kernels should get dry as soon as possible.ii) The system should be free of insect pests, i.e. it should be cleaned and disinfected.
iii) Maize should be sorted prior to loading into the drying system.
iv) It should be secure from theft by people and wildlife.
v) The system should be free from spoilage by soil, dirt, rain and other climatic factors.
d) The trainer should then select the models of the drying structures which are commonly used in the area, stressing the following points:
i) Merits and demerits of each drying structureii) Sweeping/cleaning the structures and its surroundings.
iii) Disinfecting the structures using Actellic Super dust to eliminate all common insect pests, including the GGB.
NB:
The chemistry of Actellic Super should not be explained at this stage.iv) Dehusking and sorting of maize cobs prior to placement in/on the drying structure.
v) While loading, proper care should be taken to avoid or to reduce physical damage.
vi) Routine management of the drying process, e.g.- turning the cobs where applicable
- inspecting
- preventing spoilage by rain
- securing produce from thieves, etc.
5 minutes
e) The trainer should demonstrate how to tell that the maize is sufficiently dry, e.g. by biting the kernel, moisture meter, etc. 5 minutesf) The participants should then be asked to explain how they think the drying process really occurs in the structures which they use. The trainer should assist them by demonstrating how drying takes place in each structure/system by using the lantern/candle and the model structure already loaded with cob maize.
15 minutes
a) Sun-Drying
Important Points:
i) Let direct sun rays reach the maize during the day.ii) Let water evaporate from the wet maize.
iii) Do not allow dew or mist at night to fall on the maize. Either cover the maize or put it inside the house at night.
iv) Do not let rain fall on the maize. Either cover it in such a way that water may run off or put it indoors when signs of rain appear.
b) Air-Drying
15 minutes
CRIBS
PERSPECTIVE VIEW OF THE COMPLETED CRIB
Important Points:
Sun heats the surrounding air, which is blown into the crib by the wind. The-hot air dries the maize as the cold air is blown out of the crib. The implications are:i) When constructing the crib, let the largest surface area face the direction from which the wind blows during most of the day.ii) Let it be possible for wind to be blown through by providing sufficient gaps for it but which are not so big as to allow small cobs of maize through.
iii) Do not construct a crib which is more than 1.0 meters in width (wind will not blow through easily, so drying process will be inefficient.)
iv) Provide sufficient roofing and gradient/slope of 45° so that the rain may not get through.
v) The eaves should not be longer than 0.5 m or else smooth flow of air will be interfered with.
vi) Let the crib stand raised about 1.0 meters from the ground so that rats may not get in and so that air may circulate from below.
vii) Provide rat guards (made of Kimbo cans or sheets of metal) to prevent rats from getting in.
viii) Cut down any trees, bush, etc. in the immediate surrounding which may interfere with the flow of the wind or admit pests (rats, insects, etc.).
ix) Construct the crib in the open so that air circulation may be maximized but not so far away from the house that the maize may be stolen by thieves and wildlife.
30 minutes
Important Points:
i) Maize is dried by hot smoke from the fire-place.ii) Gaps should be large enough to enable the hot smoke to go through but small enough that the small maize cobs do not drop through.
iii) The kitchen should be well thatched with a slope so that rain does not drip through.
iv) The main advantages are that nobody gets to know exactly how much maize there is up there and one does not have to keep transferring maize in and out of the house.
v) The loft has so many disadvantages which will be described later.
15 minutes
g) The trainer should now let the participants ask questions, seeking clarification of the session's content.
30 minutes
h) The contents of the session should be summarized by the trainer by:1) repeating briefly points i) to iv) of a)2) repeating briefly points i) tom v) of d) on the structures commonly used in the area
3) repeating the important points associated with the structures commonly used for drying in the area, i.e. mats, trays, cribs, loft, etc.
1 hour
i) The trainer should now ask each participating farmer to indicate how he/she dries his/her maize and how he/she may improve her method. The participant should be assisted by the trainer and other participants in identifying the improvement needs. All improvement needs mentioned by each participant should be noted down by the trainer, who should immediately fix a day and time when he/she may be able to assist the farmer to implement the improvements or to check on what will have been implemented.
