Nitrogênio e redutor de crescimento em trigo de alta produtividade

Abstract

RESUMO. Visando avaliar os efeitos da aplicação do redutor de crescimento trinexapacethyl, em diferentes épocas e doses de nitrogênio, na cultivar de trigo Avante, realizou-se um experimento em Castro, Estado do Paraná, no delineamento em blocos ao acaso, em esquema fatorial 4 x 4, com quatro repetições. Os tratamentos constaram da aplicação de 100 g ha ABSTRACT. Nitrogen and growth reducer in high yield wheat. An experiment was established in Castro, Paraná State, with the objective of evaluating the effect of trinexapac-ethyl applied at different times and in varied nitrogen rates, on the Avante wheat cultivar. The experimental design consisted of completely randomized blocks, in a 4x4 factorial scheme, with four repetitions. The treatments consisted of 100 g ha -1 of trinexapac-ethyl applied between the first and second visible node, second and third visible node, sequential application of half the rate between first and second visible nodes and half between second and third visible nodes, and control (without application). The nitrogen rates were 90, 135, 180 and 225 kg ha -1 . The study evaluated the stand; tiller number and plant height; stem diameter; lodging; nitrogen content in leaves; yield and components. Trinexapac-ethyl reduced plant height and lodging percentage. The application between the first and second visible nodes and between the second and third visible nodes promoted improved yield. The rise in the nitrogen rate increased the nutrient content in the plant and caused greater lodging, but without effect in the yield components and productivity.

Performance of white oat cultivars in response to nitrogen fertilization and trinexapac-ethyl

“…As for the cultivars IPR Afrodite and URS Corona, no significant effect of N level on plant lodging was observed, with no lodging of plants observed in these cultivars ( Figure 7B). Similar studies investigating the influence of trinexapacethyl and N fertilization in different genotypes on the lodging of plants also reported increase in the plant lodging with increasing N application level (PENCKOWSKI et al, 2009(PENCKOWSKI et al, , 2010. Pagliosa et al (2013) did not observe any effect of the growth retardant and N fertilization on the lodging of wheat plants.…”

“…In the absence of trinexapac-ethyl, the best performance for grain yield was observed in the cultivars IPR Afrodite, IPR Artemis, and URS Corona, with no significant difference between them, while the cultivar URS Guria presented the lowest grain yield. Zagonel et al (2002) and Penckowski et al (2009) also observed increased grain yield in wheat with the application of the plant growth regulator trinexapacethyl.…”

“…However, Zagonel et al (2002) observed that the application of trinexapac-ethyl increased the number of productive structures per unit area. This variability in yield components with application of trinexapac-ethyl is likely due to the climatic variation of each location and the interaction with the cultivar used (PENCKOWSKI et al, 2009).…”

Winter cereal responses to dose and application timing of trinexapac‐ethyl

“…For instance, TE applied at Zadoks growth stage (ZGS) 37 (Zadoks et al, 1974) in wheat resulted in shorter and more erect plants compared with applications at ZGS 30 and 32 (Wiersma et al, 2011). In general, higher TE doses are purported to improve stem rigidity and grain yield in wheat and other cereals (Penckowski et al, 2009;Swoish & Steinke, 2017).…”

“…Matysiak (2006) observed that application TE alone or as a mixture with Cycocel [chlormequat (2-chlorethyl) trimethylammonium chloride-MOA-Inhibits GA biosynthesis] at the second nodal stage increased grain yield and protein concentration in winter wheat. Furthermore, Penckowski et al (2009) reported that a split application of TE in spring wheat at different nodal stages improves grain yield and reduces lodging percentage. These reports suggest that higher doses or full label rates of TE are more important than the actual timing of the application.…”