Effect of Harvesting Stages on Seed and Oil Yield of Rapeseed-mustard to Suitable in a Cropping Pattern

Aim: To find out the optimum harvesting stage of high yielding rapeseed-mustard varieties to fit in rice based cropping pattern.

Study Design: The field study was arranged following RCB (factorial) design with three replications.

Place and Duration of the Study: Agronomy field of Regional Agricultural Research Station, Jamalpur (located between 24°34ʹ and 25°26ʹ North latitude and 89°40ʹ and 90°12ʹ East longitude), Bangladesh during 2015-2016 and 2016-2017.

Methodology: Seeds of mustard varieties viz. BARI Sarisha-11, BARI Sarisha-14, BARI Sarisha-15, Binasarisha-4 & Tori-7 were sown in line maintaining 30cm spacing on 02 November, 2015 and 06 November, 2016. This varieties were harvested at four different harvesting stages viz. H1= Green stage of siliquae, H2= Pale yellow stage of siliquae, H3= Golden yellow stage of siliquae and H4= Full maturity stage of siliquae. Green stage of siliquae was determined just at seven to ten days after all flower droppings of crop while the pale and golden yellow stage of siliquae was determined when 40%-50% and 70%-80% bearing turned into light yellow and deep yellow in color respectively. Full maturity stage of siliqua was determined when lower bearing just brust out.

Results: BARI Sarisha-14, BARI Sarisha-15 (B. campestris) and Binasarisha 4 (B. napus) may be harvested at pale yellow stage of siliquae at 73, 82 and 78 DAS (average of two years) considering 11.0% seed and 3.15% oil yield; 10.0% seed and 1.56% oil yield; 6.60% seed and 3.90% oil yield loss respectively than full maturity stage of siliquae.

Conclusion: BARI Sarisha-14, BARI Sarisha-15 and Binasarisha 4 need to be sown within first week of November in districts named Mymensingh (located 24°15′ and 25°15′ N and 90°49′ E longitudes), Jamalpur (located 24°34ʹ and 25°26ʹN latitude and 89°40ʹ and 90°12ʹ E longitude) and Tangail (located 24°01′ and 24°47′ N latitudes and 89°44′ and 90°18' E longitudes) and the crop should be harvested at pale yellow stage of siliquae (within 73-82 days period) sacrificing seed and oil yield loss to some extent to introduce HYVs of rapeseed-mustard in rice based cropping pattern.