Abstract
The study comprised five field experiments conducted at the experimental field of Bangladesh
Agricultural Research Institute (BARI), Joydebpur, Gazipur, Bangladesh during the Rabi
seasons of 2014-17 to screen for short duration (early maturing) high yielding rapeseed-mustard
genotypes and optimize the major management practices for further improving yield and seed
quality. Expt. 1 (2014-15) screened 30 genotypes- 19 of Brassica campestris, 6 of B. napus and 5 of
B. juncea. Expt. 2 (2015-16) trialed four selected early maturing and high yielding (Torsha,
BD-7116, B-9 and BD-7114) and one check genotypes (Tori-7) taken after evaluating the results
of Expt. 1 along with four dates of sowing (25 October, 02 November, 09 November and 16
November). Expt. 3 (2015-2016) and Expt. 4 (2015-16) examined those five selected genotypes
with nine plant densities and 5 levels of fertilizer packages, respectively. Finally, Expt. 5
(2016-17) examined the best performing treatments involving one genotype (Torsha) together
with the check Tori-7), three sowing dates (25 October, 02 November and 09 November), two
plant densities (100 and 120 plants m-2) and two fertilizer packages (N137.5-P37.5-K87.5-S15-Zn25-
B1.87 kg ha-1 and N165-P45-K105-S18-Zn03-B2.2skgha-1). The results revealed that the local check Tori-7
had the shortest field duration (77.33 days to mature) followed by BD-7114 (78.67 days),
Sonali tori (82.67 days), Torsha (84.67 days), B-9 (84.33 days), BD-7116 (86.33 days) and BARI
Sarisha-14 (86.67 days) and these genotypes, respectively yielded 0.93, 1.47 t, 1.16 t, 1.84 t, 1.75 t,
1.80 t and 1.26 t ha-1. Although there was a number of more high yielding genotypes [e.g. BARI
Sarisha-16 (yielding 2.25 t), NAP-9906 (2.16 t), BJDH-11 (2.10 t) and so on] producing >2 t ha-1
but these could not be considered under the circumstances because they were not of short
duration; often took more than 100 days to mature. Considering the days to maturity and seed
yield, four genotypes (Torsha, BD-7116, B-9 and BD-7114) were selected as of short duration
with high yields, Torsha topping the list. The seed yield of Torsha could be improved to
1.89 t ha-1 when sown on 25 October, to 1.91 t ha-1 when fertilized with N137.5-P375-K87.5-S15-Zn25-
B1.87, and to 1.95 t and 1.97 t ha-1 with the treatment combinations of Torsha with (N137.5-P37.5-
Kg7.5-S15-Zn25-B1.87 kg ha-1 x 100 plants m2x 02 November sowing) and Torsha with (N1375-Р37.5-
K87.5-S15-Zn25-B1.87 kg ha-1 x 100 plants m²x 25 October sowing), respectively. The seed oil
content was fairly high between 25 October and 02 November sowings and dropped thereafter.
Torsha had seed oil content (40.44%) significantly higher than in Tori-7 (36.10%). The ratio of
unsaturated: saturated fatty acid was greater (considered as superior oil quality) in Torsha than
in Tori-7. From these findings, it can be concluded that as the traditional genotype (Tori-7) of
mustard cultivation in the Mustard-Boro rice -T. Aman rice based cropping pattern of
Bangladesh is a losing concern to the farmers (the average seed yield is being<1.0 t ha-¹), a
simple switch over to Torsha genotype can almost double the seed yield (the increase is by
0.91 t ha-1 ~98%). Since its field duration is just one week longer than Tori-7, this genotype may
easily be adaptable within the existing cropping pattern. Further yield improvement (up to
1.96 t ha-1) of this genotype could be achieved by fixing the sowing date between the last week
of October to first week of November together with optimizing to 100 plants m2 and adopting
№137.5 -P37,5-K87.5-S15-Zn2.5-B0.85 kg ha-1 package of fertilizers.