M. M. Kamal
Scientific officer
Regional spices research centre, Bangladesh Agricultural Research Institute, Bangladesh
M. M. Akand
Scientific officer
Regional spices research centre, Bangladesh Agricultural Research Institute, Bangladesh
Onion, Pollinator, Seed yield
Regional Spices Research Centre, Bangladesh Agricultural Research Institute (BARI), Gazipur
Seed Technology
The experiment was conducted at the Regional Spices Research Centre, Bangladesh Agricultural Research Institute (BARI), Gazipur during rabi season, 2012-13 and 2013-14 to identify suitable attractant crops for increasing the vigilance of pollinators for higher seed setting and thereby increasing seed yield of onion. The land was medium high and the soil was clay loam in texture. The experiment was laid out in randomized complete block design with three dispersed replications. The distance among replications varied from 500m to 600m. In 2012-13, four treatments viz., Onion + Fennel (two rows at every 10 rows of onion including border), Onion + Black cumin (two rows at every 10 rows of onion including border), Onion + Coriander (two rows at every 10 rows of onion including border) and Sole onion were compared to achieve the objectives. In 2013-14, the treatment Onion + Black cumin was discarded and onion + Dill was included along with other treatments. The unit plot size was 11.8 x 8 m2 in 2012-2013 and 7.2 x6 m2 in 2013-14.In each plot, BARI Piaz 4 was planted maintaining 20 cm x 15 cm spacing. As per treatments, the boarder crop was planted in paired rows, maintaining 30 cm x 15 cm, 30cm x15cm, 20 cm x 15 cm and 30 cm x 15 cm spacing for Fennel (Advance line), Dill (Advance line), Black cumin (BARI Kalizira 1) and Coriander (BARI coriander 1), respectively. The crop (onion) was planted through 13-14 November 2012 and 13-15 in November 2013. The border crop was planted few days later than that of onion planting. In 2012-13, Fennel was sown on the day of onion planting, Black cumin was sown on 16 days later than onion planting and Coriander was sown on 15 days later than onion planting. In 2013-14, Fennel and Dill was planted on the day of onion planting, and Coriander was sown on 4 December (20days later than onion planting). In addition to 5 t/ha of cow dung, the crop was fertilized with N145 P83 K84 S20 Zn3 B2 kg/ha. The entire amount of cow dung P, S, Zn, B, ¼N and 1/3 K was applied during final land preparation. The rest N was applied in three equal splits at 40, 60 and 80 days after planting (DAP) in both the years.. The rest K was applied in two equal splits at 40 and 60 DAP. No additional fertilizer was used for boarder crops. To control purple blotch disease, the crop was sprayed with ‘Rovral’ @ 2g /L of water at 40, 50, 60 and 70 DAP in both the years. Similarly, to control thrips, ‘Gain’ @ 0.25 ml/L of water was sprayed at 35, 45, 55 and 65 DAP. The spray remained stopped after initiation of first blooming. One observer was assigned to each replication and observations were synchronized to run through 10.00 to 11.24. Therefore, each observer walked down 28 minutes for each treatment. An insect landing on an open umbel was considered to be a ‘visit’. The observation started from 6 February to 3 April in both the years. The observers rotated to different replications in alternate day in a cyclic order. A nearly similar observation technique was also used by 7. Starting and finishing of counting was done at the same time. The visit was counted by eye estimation. Data on plant height, scape height, number of umbel per plant, diameter of umbel, number of flowers per umbel, number of flowers setting seeds per umbel, percent seed settings, 1000-seed weight, seed yield, types of pollinator and number of vigilance were recorded. Except vigilance, all other data were analyzed and mean separation was done by DMRT following MSTAT software.
IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS) e-ISSN: 2319-2380, p-ISSN: 2319-2372. Volume 10, Issue 5 Ver. I (May. 2017), PP 88-96 www.iosrjournals.org
Journal