Abstract
Nine experiments were carried out during 2010 to 2013 at USDA-Alliums' Field Laboratory, Horticulture Farm, Bangladesh Agricultural University, Mymensingh to study the seed production technique of carrot with the objective to increase the yield and quality of carrot seeds through management practices and vernalization. The higher seed yield (1363.28 kg/ha) was obtained from the variety Brasilia Agroflora with the spacing of 20 cm x 25 cm while maximum seed germination (90.69%) and seed vigour index (13.38) were obtained from the same variety with the widest spacing (25 cm x 30 cm). The lower seed yield (793.37 kg/ha) was found from the variety Prima Agroflora with the spacing of 25 cm x 30 cm while minimum seed germination (74.17%) and seed vigour index (9.54) were obtained from the same variety with the lowest spacing (20 cm x 20 cm). The seed yield (1348.95 kg/ha) and seed germination (89.03%) were significantly the higher in Brasilia Agroflora variety with the application of 3 kg B/ha and 4 kg Zn/ha treatment. But the lower seed yield (836.18 kg/ha) and seed germination (72.17%) were found in Prima Agroflora with control treatment. The seed yield (1299.58 kg/ha), seed germination (86.63%) and seed vigour index (12.71) of Brasilia Agroflora were the highest from the fertilizers combination of N124P52K120S3.6Zn3B2Cu2Mo2 kg/ha. while the lowest seed yield (750.37 kg/ha), seed germination (74.28%) and seed vigour index (9.63) were found from control treatment of same variety. The lowest time to 50% flowering (54.39 days) with the highest seed yield per hectare (1283.07 kg) in Prima Agroflora were obtained from the treatment of 150 ppm GA3 while the highest time (65.02 days) was required from control treatment and the lowest seed yield per hectare (846.11 kg) was found from the treatment of IAA 250 ppm with the same variety. In respect of seed quality, the highest seed germination (87.37%) with the seed vigour index of 12.59 were obtained from GA3 at 200 ppm while the lowest seed germination (73.32%) with a seed vigour index (9.97) were observed from control treatment. In case of variety with the date of transplanting stecklings, the higher seed yield (1377.17 kg/ha), seed germination (90.69%) and seed vigour index (13.15) were obtained from the variety Brasilia Agroflora with 1 December transplanting of stecklings. But the lower yield (728.21 kg/ha), seed germination (69.22%) and seed vigour index (9.18) were found from the variety Prima Agroflora with 15 January transplanting of stecklings. In case of extent of root cut of Brasilia Agroflora with treating fungicides on cut portion revealed that 25% root cut with Dithane M-45 treatment gave the highest seed yield (1367.05 kg/ha), seed germination (90.99%) and seed vigour index (13.42), whereas root cut of 75% with no fungicide treatment gave the lowest seed yield (909.63 kg/ha), seed germination (73.75%) and seed vigour index (9.80). The variety Brasilia Agroflora with 8°C temperature treated seeds resulted the higher seed yield (1385.58 kg/ha), seed germination (89.24%) and seed vigour index (13.61) while the variety Prima Agroflora with room temperature treated seed gave the lower seed yield (873.37 kg/ha), seed germination (72.28%) and seed vigour index (9.66). The variety Brasilia Agroflora with 12°C temperature treated stecklings exhibited the higher seed yield (1435.45 kg/ha), seed germination (91.36%) and seed vigour index (13.49), whereas the variety Prima Agroflora with room temperature treated stecklings showed the lower seed yield (869.55 kg/ha), seed germination (68.39%) and seed vigour index (9.80). From the findings of the above experiments, four technology packages were selected on the basis of performance. The variety Brasilia Agroflora with the package- seed treated at 8°C temperature, 25% root cut, treated with Dithane M-45, stecklings treatment at 12°C, transplanting 1 December, spacing 20 cm × 25 cm, N124P52K120S3.6Zn4B3Cu2Mo2 kg/ha fertilizers application; foliar spray of 150 ppm GA3 - gave the higher seed yield (1507.68 kg/ha), germination (90.19%) and vigour index (13.41).