PERFORMANCE OF MEPIQUAT CHLORIDE ON GROWTH, YIELD AND OIL CONTENT OF SUNFLOWER

Abstract

A field experiment was conducted at research field of Sher-e-Bangla Agricultural University, Dhaka during the period from November 2020 to March 2021 in Rabi season to study the performance of mepiquat chloride on growth, yield and oil content of sunflower. The experiment consisted of two factors, and followed split-plot design with three replications. Factor A: Sunflower varieties- (2) viz: V = BARI Surjumukhi-2, V = Mayabi Hybrid (China variety) and Factor B: Mepiquat chloride application level- (5) viz: M 2 0 = Control, M 1 = 12.5 ml ha -1 , M 2 = 25.0 ml ha = 37.5 ml ha -1 and M 4 = 50.0 ml ha -1 . Experimental results revealed that different varieties and mepiquat chloride application significantly influenced the seed yield and yield contributing characteristics of sunflower. In case of different sunflower varieties the lowest seed yield (2.15 t ha -1 ) was obtained from V treatment (BARI Surjumukhi2).

Whereas cultivating Mayabi Hybrid (V 2 1 ) variety gave the highest head diameter (16.69 cm), seeds head -1 (611.93), seed yield (2.36 t ha -1 1 -1 ), biological yield (7.97 t ha ) and harvest index (29.52 %) while BARI Surjumukhi-2 (V ) cultivar dominated in 1000-seeds weight (60.91 g) and oil content percentage (38.56 %). Among the 5 doses of mepiquat chloride, the highest two doses (M 3 and M 4 1 ) produced the highest seed yield (2.55 and 2.62 t ha -1 , respectively) and shortest plant. These two treatments also showed highest stem diameter, dry weight plant -1 , SPAD value, head diameter, seeds head -1 and 1000-seed weight. However, lower doses of mepiquat chloride (M

and M ) treatment showed highest oil content (in percentage). Regarding interaction, V 2 M 3 3 and V 2 M 4 were maximum seed yielder (2.72 and 2.74 t ha -1 , respectively) and produced shorter plants than other interactions which was attributed to higher head diameter, seeds head -1 and 1000-seed weight in these interaction treatments. These two interactions also showed higher growth and yield attribute parameters. On the other hand, V 1 M 1 and V 1 M interactions gave maximum oil content. Considering all, it may be concluded that Mayabi Hybrid (V 2 2 ) and mepiquat chloride dose 37.5 ml ha

(M ) and their interaction seems promising for reducing plant height and increasing seed yield but for oil content (%), BARI Surjumukhi-2 (V 3 ), lower mepiquat chloride dose and their interaction was found best for sunflower.