INFLUENCE OF TRANSPLANTING DATE ON GROWTH AND YIELD OF BORO RICE VARIETIES IN LALMAI-HILL AREA

Abstract

A field experiment was conducted in Lalmai-hill area of Cumilla with five recently BRRI released rice varieties during boro season (2018-2019) to evaluate their yield performance under different transplanting dates. Rice seedlings were transplanted on three different dates viz., January 15 (T 1 ), January 30 (T 2 ) and February 14 (T 3 ) which were considered as transplanting date treatments. Five rice varieties viz., BRRI dhan67 (V 1 ), BRRI dhan68 (V 2 ), BRRI dhan74 (V 3 ), BRRI dhan81 (V 4 ) and BRRI dhan86 (V 5 ) were considered as varietal treatments. Results showed that transplanting date had great impact on growth and yield of boro rice. Advancement of transplanting date or delaying of transplanting date decreased effective tillers, filled grains panicle , total grains panicle ─1 , thousand grain weight, grain yield, biological yield and harvest index. Compared to early-planted seedlings (T 1 ), late-planted seedlings (T 3 ) decreased effective tiller hill ─1 , filled grains panicle ─1 , grain yield and biological yield by 13, 14, 24 and 9%, respectively. Varietal variation also influenced the growth and yield of rice. The highest grain yield (5.95 t ha ─1 ) and biological yield (14.33 t ha ─1 ) were obtained from BRRI dhan74 compared with other varieties because of higher potentiality of its yield attributes. Combination of transplanting date and variety also influenced growth and yield of boro rice. The highest grain yield (6.67 t ha ─1 ) and yield return in terms of monetary advantages (Tk. 158765 ha –1 ) were recorded from BRRI dhan74 when transplanted on January 15 whereas, lowest grain yield (3.36 t ha –1 ) and yield return (Tk. 98350 ha –1 ) were recorded from BRRI dhan86 when planted on February 14. Transplanting of all other varieties on January 15 confirmed higher yield and yield return compared with delayed transplanting (January 30 and February 14). However, transplanting of any boro rice seedling after January 30 decreased growth, yield and yield return in Lalmai-Hill area.