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Chapter 7 The use of bees for pollination
The practice of using bees to pollinate fruit crops is as new as the beekeeping industry in most parts of tropical Africa, although the practice has started in a few places in northern and southern Africa. This short chapter describes how farmers could utilize it to great advantage.
Chapter 1 of this manual has already said a good deal about the need for such an activity in the African agricultural economy, on a great continent where hunger, malnutrition and desertification are enormous problems. From flowers, the honeybees collect large quantities of nectar for the production of honey to feed themselves and pollen for feeding their young. In the collection process, the insect pollinates thousands of different kinds of plants, including edible and cash crops. According to Prof. E.C. Martin, the value of bee pollination of fruits, vegetables and seeds in the United States of America totalled very close to $8 billion in the 1960s; the figure 20 years later is probably close to $20 billion.
Prof. Martin goes on to calculate that foods derived from insect-pollinated plants represented about one-third of the total food consumed in the USA in 1970. This amounted to $40 billion. He concludes:
"Many parts of the world are blessed with similar variety and nutritive quality in their available food supply. If less fortunate parts of the world are to improve their diets to include more meat, dairy products, fruits and vegetables, there will be need for great world-wide increases not only in bee-pollinated crops but also in bees and beekeepers to carry on the pollination and particularly an increase in knowledge and understanding of what a potent force in food production and human nutrition the honeybee activity is."
In Africa, many crops depend on the wind for their pollination, including cereals: millet, guinea corn, maize and rice. Plantain, cocoyam and yam also do not need insects to pollinate them. But most leguminous vegetables; cash crops such as coffee, cola nut, cocoa, coconut, palm, cashew and shea butter; fruits such as the mango and citrus; and many other plants cannot be pollinated without insects.
The insect forages for nectar and pollen from several thousands of plant species and in the process pollinates a wide variety of crops important for the survival of life. While bees may visit many species of plants in a day, a forager may also constantly visit one plant, sometimes for several days, until there is no more nectar or pollen to collect.
Pollen is a vital food for the brood of the honeybee. The bee needs it in the hive, but the flower also needs the bee to fertilize it. The bright colour and sweet odour of the flower combine to attract insects. The honeybee, which has a powerful sense of smell and a keen sense of sight, is easily attracted to the flower. In the process of gathering both nectar and pollen, it incidentally transfers some pollen from the flower's male organs, the anthers, to its female organ, the stigma. The pollen germinates, and penetrates to the plant's ovaries, where the seeds are formed.
The honeybee starts its foraging activity between 5:00 and 5:15 a.m. Flight usually depends on the weather and temperature. The honeybee will not leave the hive if the temperature is below 14°C or if the wind speed is above 30 kilometres per hour. To be effective, therefore, pollination should take place in warm, clear weather, but too much heat has the same adverse effect as too much cold. If the weather is hot, dry and windy, the flower's stigma may dry out, so that pollen deposited does not germinate. Pollen may also not be available in conditions of continuous rainfall, since flowers are usually scarce during the rainy season. Thus, areas of frequent rainfall offer few flowers for bee activity.
The honeybee is the only insect that can successfully be moved from farm to farm. It is estimated that five average colonies (about 50 000 bees each) can work a two-hectare plantation. This is achieved by moving colonies and siting them close to the farm.
How to move bees
The beekeeper must study carefully the temperament of his bees, and keep a record of the seasons when they are friendly or aggressive in his locality, because during certain periods of the year, bees can be transported easily without precautionary measures against aggression and stinging.
A motorized lorry is an indispensable tool for the professional beekeeper. Bees cannot be moved by head-load. The top-bar hive cannot be transported over long distances on poor roads or tracks, and therefore hives that are to be transported frequently must be fitted with movable frames. The hives should have a ventilation hole about two centimetres in diameter, covered with mosquito mesh. Their bottom board should be coated with termite-repellent paint.
The hives should be light enough to be loaded and unloaded easily. Combs with capped honey should be removed to reduce weight, while uncapped combs should be retained in the hive. Before loading, hives should be inspected and all unwanted openings sealed with wood and wax, since they can create problems if the bees come through them and cluster outside the hive. However, bees tend to cluster quietly in moving vehicles and rarely attempt to fly away or cause any harm until movement stops.
In general, bees are less troublesome riding at night. Hives should be loaded in the evening, when most of the bees have returned from foraging. The bees clustered at the entrance are smoked to drive them into the hive. The entrance is then sealed, and the ventilation hole is opened to allow air to circulate through the hive. Hives can be stacked one above another. They should be packed closely and neatly, and secured with a trucer's rope. The journey and the reinstallation of the hives should take place at night: hives should be unloaded and installed before sunrise, because the bees will be ready to leave shortly after that time. To assist in the night work, a flashlight with a red bulb, or covered with red cellophane, is a useful tool, because bees cannot detect red light and are therefore not disturbed by it.
Pollination programmes
Fruit-growers should be encouraged to keep their own bees to ensure that their crops are properly pollinated. Growers who for any reason do not wish to keep bees should be advised to use the services of a beekeeper who has colonies to move about for the purpose.
In order for a pollination programme to work successfully, it is important that the farmer and the beekeeper work in close collaboration, because both have an essential role to play. yell before he needs the bees (where bees are scarce, several months' notice may be necessary), the farmer should contact the beekeeper to make detailed arrangements. At this time they should agree on a number of points, and it is often advisable for the agreement to be written down in a simple contract. Among the things they should agree on, these are possibly the most important:
1. The number and the strength of the colonies to be provided. Rented colonies should be queen-right, with at least four brood combs;
2. The dates of delivery and removal of the colonies;
3. The distribution of the hives on the farm;
4. The fee and schedule of payments. This is negotiable and depends on a number of factors, including proximity and transport costs, the quantity and quality of honey produced from the crop, and the risks, if any, involved in the operation. Due to the fact that he can expect two different benefits from the operation, the beekeeper should be prepared to charge moderate prices;
5. Ownership of the honey produced. Normally, the honey belongs to the beekeeper. If not, his fee is likely to be higher;
6. The right of the grower to verify that the colonies are up to strength. However, the grower should never attempt to open hives without the consent of the beekeeper. Colonies can be simply inspected by counting the number of returning foragers: on a warm, bright day during the flowering period, 100 bees returning to the hive within one minute is usually regarded as very good;
7. Restrictions on the use of insecticides or pesticides toxic to bees, not only during the rental period but for a specified period before it begins. This is important because the farmer owes it not only to the beekeeper but also to himself to be sure that the colonies are strong, and therefore that he does not kill bees by the wrong use of pesticides;
8. Precautions to be taken against bush fires;
9. Liability for random stinging by bees, for vandalism, for livestock damage, and for theft of hives.