Sunflower response to repeated foliar applications of Paclobutrazol

Abstract

-Paclobutrazol (PBZ), a well-known growth retardant of the triazole family, is mostly used for controlling plant size and growth, resulting in more desirable compact plants for floricultural purposes; however, limited experimental data are available for use of PBZ in field sunflower. The objective of this study was to evaluate the effect of repeated foliar applications of PBZ at rates of 50 + 50 g ha -1 (double application) and 50 + 50 + 50 g ha -1 (triple application) on sunflower morphology and productivity. PBZ applications corresponded to growth stages of four to five, five to six, and six to eight true leaves of sunflower plants, respectively. The double foliar application of PBZ reduced sunflower plant height at maturity by 4.4% (or by 11.7 cm). The triple foliar application of PBZ reduced sunflower plant height at maturity by 14.4% (or by 49.2 cm). However, PBZ either in the double or the triple application reduced achene yield per plant by 25.6% and 22.5% and the 100-achene weight by 11.4% and 25.0%, respectively, compared with the non-treated control. Overall, the repeated foliar applications of PBZ at the rates tested in this study, apart from providing a reduction of sunflower plant height, had major adverse effects on achene yield and weight. Thus, different application schemes of PBZ or perhaps different growth regulators should be investigated to control plant height in sunflower.Keywords: Achene yield, growth retardants, height, lodging. RESUMO -Paclobutrazol (PBZ) é um bem conhecido retardador de crescimento da família triazol utilizado principalmente para controlar a altura e o crescimento das plantas, resultando em indivíduos

Seed Invigoration with Paclobutrazol Improves Seedling Growth, Physiological, Biochemical Attributes and Fruit Yield in Okra

“…1). These findings were in accordance with previously reported investigations by Kumar et al (2012) in camellias (47.5% reduction), Syahputra et al (2013) in rice plants, Koutroubas and DamLas (2015) in sunflower. Decrease in plant height was associated with the inhibition of gibberellin synthesis (Deneke and Keever 1992;Setia et al 1995;Berova and Zlatev 2000) and decrease in internodal length (Tesfahun and Menzir 2018).…”

The Role of Paclobutrazol on Production Strategy of Curcuma alismatifolia Gagnep. for Off-Season Marketing

“…Therefore, those results were significantly different compared to other treatments. Our results agreed with the finding that in field-cultivated Helianthus annuus L. [15] and Dendranthema x grandiflora cv. Lilian Hoek [16], the effects of higher concentrations of PBZ include reduction in plant height and root length.…”

Effect of Different Levels and Time of Application of Paclobutrazol on Morphology, Yield and Yield Attributing Characters and Economics of Groundnut (Arachis hypogaea L.)

“…Paclobutrazol, being a triazole growth retardant inhibit biosynthesis of gibberellins by blocking kaurene oxidase resulting in decreased inter-nodal elongation. Similar results on variation in height due to application of paclobutrazol was also reported by kumar et al (2012), Koutroubas et al (2015Koutroubas et al ( ), kumar et al (2016 and Barman et al (2017).…”