Effect of Zinc and Boron in Combination with NPK on Sunflower (Helianthus annuus L.) Growth and Yield

Abstract

A field study was undertaken at Oilseed Section, Agriculture Research Institute, Tandojam during autumn 2013 to evaluate the effect of zinc and boron in combination with NPK on sunflower growth and yield. The experiment was laid out in a three replicated randomized complete block design. The treatments comprised of: 90-45-45 NPK kg/ha^-1, NPK + 10 + 1.5 Zn + B kg/ha^-1, NPK + 15 + 1.5 Zn + B kg/ha^-1, NPK + 15 + 2.0 Zn + B kg/ha^-1 and NPK + 20 + 1.5 Zn + B kg/ha^-1. The results showed that zinc, boron and NPK in combination with each other caused significant (P<0.05) effect on growth and yield traits of sunflower variety HO-1. The plots receiving NPK + 20 + 1.5 Zn + B kg/ha^-1 produced maximum plant height (160.6 cm), stem girth (3.6 cm), head diameter (20.4 cm), seeds per head (1255.3), seed weight (60.9 g head^-1), seed index (1000-seed weight: 64.8 g) and seed yield (2386.0 kg/ha^-1), closely followed by plots fertilized with NPK + 15 + 2.0 Zn + B kg/ha^-1 resulting in 157.8 cm plant height, 3.4 cm stem girth, 18.6 cm head diameter, 1189.3 seeds per head, 53.3 g head^-1 seed weight, 62.9 g seed index (1000-seed weight) and 2314.0 kg/ha^-1 seed yield whereas, NPK + 15 + 1.5 Zn + B kg/ha^-1 ranked 3rd with 153.8 cm plant height, 3.3 cm stem girth, 17.8 cm head diameter, 1150.0 seeds per head, 57.3 g head^-1 seed weight, 62.3 g seed index (1000-seed weight) and 2277.7 kg/ ha^-1 seed yield. However, minimum plant height (144.1 cm), stem girth (3.0 cm), head diameter (16.2 cm), seeds per head (1013.0), seed weight (46.7 g head-1), seed index (1000-seed weight: 57.6 g) and seed yield (2030.7 kg/ha^-1) was observed in plots where 90-45-45 NPK kg/ha^-1 (Control) was applied. Hence, results indicated that application of micronutrients (zinc and boron) in combination with macro-nutrients (NPK) enhanced the growth and yield performance of sunflower. Although at higher doses of Zn and B numerically higher yield was noted but application of NPK + 15 + 1.5 Zn + B kg/ha^-1 showed non-significant differences with NPK + 20 + 1.5 Zn + B kg/ha^-1 and NPK + 15 + 2.0 Zn + B kg/ha^-1 almost in all the growth and yield parameters, particularly seed yield.

Keywords: Sunflower, Zinc, Boron, NPK, growth and yield