Chhuneja, Pardeep KumarHarmanjot Singh2019-04-222019-04-222019http://krishikosh.egranth.ac.in/handle/1/5810100819The studies on the ‘Bee pollination requirement and honey production potential of oilseed crops’ conducted on sesame (Sesamum indicum L.) cultivar Punjab Til No. 2 at Punjab Agricultural University (PAU), Ludhiana, and on African sarson (Brassica carinata A. Braun) cultivar PC-6 at University Seed Farm (USF) Ladhowal revealed that out of 9 and 14 flower visiting insect species recorded from the respective crops, 97.9 and 74.4 per cent were Hymenopterans, predominantly Apis spp. These pollinators were the most abundant during morning and noon hours on sesame and African sarson blooms, respectively. On Sesame, the foraging intensity of the honey bees was in the order of Apis dorsata>Apis mellifera>Apis cerana while the foraging rate was in the order of A. cerana> A. dorsata>A. mellifera. Apis florea was not found foraging on sesame flowers. Mean per cent A. mellifera, A. cerana and A. dorsata bees foraging for nectar ranged between 84.4-100.0, 46.7-100.0 and 82.3-100.0, respectively. All Apis bees worked as top foragers in sesame. The highest mean number (‘000) of loose pollen grains were recorded from A. dorsata (18.4) followed by that from A. mellifera (11.8) and A. cerana (7.6) at 0600 h. Pollination of sesame by A. mellifera resulted in 66.9 capsules per plant, 32.0 seeds per capsule and 12.2 quintal seed yield per hectare which was at par with open pollinated and pollinators’ exclusion treatments. Increase in the bee visits did not result in any significant increase in seed weight per capsule (84.2 mg in 0 bee visit and 86.0 mg in 5 bee visits). Overall, there was neither any significant enhancement in seed yield nor in seed quality (germination and oil content) of sesame. Mean quantity of nectar production was 20.6 mg per 25 flowers and mean sugar concentration of the nectar was 5.24 per cent. Honey production potential of sesame was worked out to be 2.5 kg per ha. On this crop, the foraging intensity of the honey bees was in the order of A. mellifera>A. cerana>A. dorsata>A. florea while the foraging rate was in the order of A. cerana>A. mellifera>A. dorsata>A. florea. Proportion of pollen gathering belonging to A. mellifera, A. cerana, A. dorsata and A. florea bees ranged between 15.8-33.8, 11.3-22.6, 16.0-31.9 and 15.5-24.1 per cent, respectively. The mean proportion of top foragers was in the order of A. dorsata>A. mellifera>A. cerana>A. florea. The highest mean number (‘000) of loose pollen grains were recorded from A. dorsata (17.6) followed by that from A. mellifera (14.3) and A. cerana (12.0) at 0900 h while it's number was the lowest on A. florea (6.5) at 1100 h. A. mellifera was ranked as the most efficient pollinator on the basis of its highest pollination index (1.79) while pollination efficiency of A. mellifera was 16.4. Five visits of A. mellifera resulted in the highest seed weight per pod i.e. 32.1 mg while it was 7.7 mg under no bee visit. Pollination of African sarson by A. mellifera resulted in 26.2, 131.1 and 412.8 per cent increase in the number of pods per plant, number of seeds per pod and seed yield, respectively over exclusion of pollinators. Open pollination and bee pollination alone resulted in 52.75 and 42.52 per cent increase in seed germination and 61.44 and 58.23 per cent increase in oil content over pollinators’ exclusion. Pollination requirement of African sarson was worked out to be one 10 bee-frame A. mellifera colony per hectare. Mean quantity of nectar production was 12.0 mg per 25 flowers with mean sugar concentration of 18.6 per cent. Honey production potential of African sarson was calculated to be 8.9 kg per ha.ennullThesis