The rubber tree is prolific producer of honey. The honey flow period of Hevea ranges from January to mid April and during this period honey bees collect large quantities of nectar from the extra-floral nectary glands at the distal end of petioles where the leaflets join. Though the nectariferous bud scales and nectariferous glands on the lower surface of the lamina secrete small amounts of nectar, only the nectariferous glands on the petiole tips are found to be visited by the bees for nectar. Lack of nectar during the prolonged period from April to December in rubber plantations in India necessitates interim bee flora for off-seasonal arrangements for the Indian Honey bee, Apis cerana indica F. Introduction of five major alternative been forage plants viz. Antigonon leptopus, Callistemon lanceolatus, Manihot glaziovii, Pongamia glabra and spp. in association with 21 major sources of nectar and pollen made a full complement of alternative bee flora for off-seasonal management of honey bee colonies in rubber plantations. Hevea brasiliensis records a decline in honey flow in late March. While the introduced alternative bee flora maintain their flowering till December, resulting in a shift in the foraging rhythm of bees from the former to the latter.
It is estimated that the annual production of honey from rubber plantations in India is about 2750 tonnes, which forms 40% of the total honey production in the country. Assuming even a production potential of 10 kg per hive and 15 hives per hectare, the total production in India could be enhanced to around 45 000 tonnes under scientific management. Assuming that 30 hives can be managed by a bee-keeper, the rubber plantation industry can give part-time employment to 150 000 people.
More than 90% Indian honey bee colonies were lost in the year 1992 due to Thai sac brood viral disease. Many disease resistant colonies are also identified. The introduction and management of the European honey bees (Apis mellifera) is also in progress in rubber plantations.
Key words: rubber plantations, honey.
Correspondence: M.R. Sethuraj, Rubber Research Institute of India, Kottayam, Kerala, India-686 009