Dr. Abdullah Al Mamun
Professor
Department of Agronomy, BAU, Mymensingh-2202.
Six experiments were done in the Agronomy Field Laboratory, BAU, Mymensingh during the period under report to see the effects of variety, spacing, fertilizer dose, time of harvest and cutting height of the main crop and weeding regime, irrigation and nitrogen management in the ratoon crop on the ratooonability of boro rice. The varieties studied were BR16, BR24, BR26, BRRI dhan27, BRRI dhan28, BRRI dhan29, BRRI dhan35, BINA dhan6 and Nayanmoni. Among these varieties BRRI dhan28 produced the highest grain yield in the ratoon crop showing its superior – most performance in producing effective tillers/hill, panicle length and grains/panicle. The highest grain yield was produced by the crop spaced at 20cm × 20cm and it also took shortest time of mature. Among the five fertilizer doses applied in the main crop viz. F1 (N=90, P2O5=45, K2O=50, S=13, Zn=4 kg/ha), F2 (N=105, P2O5=55, K2O=60, S=13, Zn=4 kg /ha), F3 (N=120, P2O5=65, K2O=70, S=13, Zn=4 kg/ha), F4 (N=135, P2O5=75, K2O=80, S=13, Zn=4 kg/ha) and F5 (N=150, P2O5=85, K2O=90, S=13, Zn=4 kg/ha), the dose F5 producing the superior-most yield attributes yielded the highest in the ratoon crop. Nitrogen when applied at 100 kg/ha one week after harvest of the main crop produced the highest grain yield in the ratoon crop. Harvesting of the main crop at 30 days after 50% flowering and cut at a height of 25 cm produced the highest grain yield. The ratoon crop when weeded twice 7 and 14 days after harvest of the main crop yielded the highest. Among the six irrigation levels tried viz. I0 (no irrigation after harvest of the main crop), I1 (Keeping the crop moist all through after harvest of the main crop), I2 (one irrigation given 7 days after harvest of the main crop), I3 (two irrigation given 7 days and 28 days), I4 (5 cm standing water maintained from 7 days after harvest of main crop) and I5 (10 cm standing water maintained from 7 days after harvest the main crop), the highest grain yield accompanied by superior performance of the crop characters was obtained from the ratoon crop raised by I1. In all of these studies the yield and most of the crop characters of ratoon crop were inferior to, and the crop duration was shorter than, those of the main crop.
Regenerative Rice, Agronomic practices, Ratoon crop, BR16
Department of Agronomy, BAU, Mymensingh.
Food Safety and Security
Bangladesh Agricultural University Research Progress. Proceedings of the workshop 15-16 January 2005. Bangladesh Agricultural University Research System (BAURES), Mymensingh, Bangladesh.
226800
Report/Proceedings