Effects of paclobutrazol on growth and yield attributes of groundnut (Arachis hypogaea L.)

A field experiment was carried out to investigate the effect of paclobutrazol (PBZ) as a growth retardant on excessive vegetative growth and yield of groundnut (Arachis hypogaea L.) at District Seed Farm, under Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal during kharif season in 2013 and 2014. The experiment was in split-plot with 6 main-plot treatments (PBZ @ 0, 50, 100, 150, 200 and 250ppm) and 3 sub-plot treatments (single spraying at 30 and 50 days after emergence (DAE) and double spraying at 30 and 50 DAE). During reproductive stage significantly shorter plants (upto 28% less plant height) were observed due to PBZ application as compared to control. At harvest significantly higher dry matter production was recorded from PBZ @ 250ppm (232.1 g m⁻²) and from double spraying at 30 and 50 DAE (231.1 g m⁻²). The number of pod plant⁻¹ and sound mature kernel (%) had showed positive impacts and finally increased the dry pod and haulm yield. The maximum dry pod yield was 1745 kg ha⁻¹ and 1610 kg ha⁻¹ with PBZ @ 250ppm and double spraying at 30 and 50 DAE, respectively. The highest benefit: cost ratio was also from PBZ @ 250ppm and double spraying at 30 and 50 DAE. A highly positive correlation among different attributes were recorded except plant height which was negatively correlated with other attributes i.e. dry matter production, number of pods plant⁻¹ and yield was recorded. Therefore, PBZ @ 250ppm with double spraying had considerable positive influences on number of pod plant⁻¹, total dry pod yield (Kg ha⁻¹) of groundnut as well as on the benefit: cost ratio.