Response of potassium nitrate on yield and yield contributing characters of boro rice cv. BRRI dhan28

Abstract

The experiment was conducted at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh, to explore the growth and yield performance of boro rice cv. BRRI dhan28 is influenced by foliar spray of potassium nitrate (KNO3) at four rice growth stages. The experiment consisted of four doses of KNO3 viz. 0 (Control), 0.25, 0.50 and 1.00 kg ha−1 and applied at four growth stages of rice development viz. at panicle initiation, at ear emergence, at anthesis period and at dough stage. This experiment was carried out in Randomized Complete Block Design (RCBD) with three replications with 10 m2 (4.0 m × 2.5 m) unit plot size and spacing between blocks and unit plots was 1 m and 0.5 m, respectively. Results revealed that foliar application of potassium nitrate at four growth stages significantly affected yield and yield contributing characters of BRRI dhan28. But most of the yield contributing characters did not differ significantly due to the interaction between potassium nitrate and stage of foliar spray. However, the foliar application of KNO3 @ 0.25 kg ha−1 showed the highest yield production (5.86 kg ha−1) while the lowest yield (4.85 kg ha−1) was found in control. Furthermore, better yield performances were recorded when the KNO3 was applied at panicle initiation stage rather than the other four growth stages. The total number of tillers, 1000–grain weight and grain yield, was higher with foliar spraying of a 0.25 kg ha−1 KNO3 at panicle initiation stage. From this experiment, it may be concluded that foliar application of KNO3 affected the yield performances of BRRI dhan28 and 0.25 kg ha−1 KNO3 produced the highest grain yield when applied at panicle initiation stage of boro rice.