Pollination biology in oilseed Brassica and foraging behavior of pollinators in intercropping ecosystem
| dc.contributor.advisor | Khan, M.S. | |
| dc.contributor.author | Sajwan, Rahul | |
| dc.date.accessioned | 2021-12-03T07:17:49Z | |
| dc.date.available | 2021-12-03T07:17:49Z | |
| dc.date.issued | 2021-10 | |
| dc.description.abstract | The present study was conducted to determine the effect of flower biology and phenology of oilseed Brassica on the foraging behavior of pollinators and the effect of intercropping (fennel, coriander and chickpea) on the abundance of pollinators in seven species of oilseed Brassica at Norman E. Borlaug Crop Research Centre in GovindBallabh Pant University of Agriculture and Technology, Pantnagar (Uttarakhand) during the rabi season 2020-21. In different Brassica species, length of petal and width ranged from 7.82-13.79mm to 3.33-7.92mm, while style and sepal length ranged from 4.55-9.57mm and 3.85-7.82mm. Various Brassica species completed 50% flowering stage in 53-118 days after sowing and the flower longevity lasted from 3-8 days during different blooming time. Anther dehiscence started at 7.00hr and maximum flowers were opened up until 10.00hr. Flower of various Brassica species showed introse and extrose positions of anthers respectively during the day hours. Pollen and ovule size ranged from 21.65 - 31.81μm and 297.51-413.22 μm respectively, and number of pollen grains varied from 5500-17000 and ovules 7-38 in different oilseed Brassica species. Stigma receptivity was maximum between 11.00-13.00hr. On the basis of flower phenological study B. napus var. GSC-6, B.alba and B. carianata were considered showing superior characters among eight oilseed Brassica varieties. The population of insect visitors was higher in oilseed Brassica experiment as compared to intercropping experiment. A total of 28 insects belonging to 13 families under 5 orders were found to visit the different oilseed Brassica bloom. In intercropping ecosystem, 22 species belonging to 11 families under 5 orders were recorded. Order Hymenoptera contributed higher percentage of the insect visitors. Major flower visitors of oilseed Brassica were Apismellifera, A. cerana, A dorsata, A. florea and Halictus species. Halictus species was dominant visitor of B. nigra while A. mellifera was dominant visitor of all other Brassica species followed by A. cerana. However, among Brassica species A. mellifera and A. florea were most abundant pollinators in B. carinata while A.cerana and A. dorsata were most abundant pollinators in B. campestris var. BSH-1 and B.napus var. GSC-6, respectively. The studies on varietal preference of oilseed Brassica to bee pollinators indicated that B. nigra was most preferred by bees followed by B. carinata, B. napus var. GSC-6, B.juncea var. PM-31 and B. campestris var. BSH-1. Foraging rate of Apis species on different cultivars revealed that A. mellifera had highest foraging rate (11.27 flowers/min) followed by A.cerana (8.47 flowers/min) and lowest of A. dorsata (4.15 flowers/min) and bee species indicated highest foraging rate on B. napus var. GSC-6 (11.48 flowers/min) followed by B. alba (10.10 flowers/min) and B. nigra(8.88 flowers/min). The observations on foraging speed revealed that time spent byApis species was maximum on cultivars of B.juncea var. PM-31(4.23 sec/flower) followed by B. campestrisvar. BSH-1 (3.95 sec/flower) and B. napus var. GSC-6 (3.52 sec/flower). Among the Apisspecies, A. mellifera spent maximum time (3.92 sec/flower) on flower followed by A. cerana(3.79 sec/flower), A. florea (3.20 sec/flower) and minimum time spent by A. dorsata (1.9 sec/flower). Pollinator activity was maximum between 10.00-12.00 hr. Apisflorea carried significantly higher loose pollen load (31371 pollen grains) followed by A. mellifera (26171 pollen grains), A.cerana (17142 pollen grains), Halictus species (12800 pollen grains) and A.dorsata (5371 pollen grains) and maximum amount of pollen was collected by Apis species from B.juncea var. Varuna (28000 pollen grains) and B. nigra(27280 pollen grains). Apismellifera was the most efficient pollinator in different oilseed Brassica with pollination efficiency index (743.25) followed by A. florea(323.12), A.cerana (221.14), Halictus species (147.20) and A. dorsata (24.70). Mustard intercropping with coriander had a positive effect on increasing the diversity of insect visitors rather than increasing the abundance ofApis species. The blooming phases of mustard intercropped with fennel and chickpea were not synchronized, therefore, fennel and chickpea as intercrop had no effect on pollinator’s abundance. The abundance of bee pollinators on oilseed Brassica flowers was positively influenced by high temperature, sunlight hours, and wind velocity, whereas the number of bee pollinators was negatively influenced by low temperature and relative humidity. Size of flower characters of oilseed Brassica species had positive influence on abundance of A. mellifera and A.dorsata, whereas A. florea and Halictus species showed negative correlation with size of flower characters. | en_US |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810178555 | |
| dc.keywords | pollination, biology, oilseeds, Brassica, foraging, pollinators, intercropping, ecosystems | en_US |
| dc.language.iso | English | en_US |
| dc.pages | 214 | en_US |
| dc.publisher | G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand) | en_US |
| dc.research.problem | Oilseeds | en_US |
| dc.sub | Entomology | en_US |
| dc.theme | Pollination | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | Pollination biology in oilseed Brassica and foraging behavior of pollinators in intercropping ecosystem | en_US |
| dc.type | Thesis | en_US |