Ethephon Sprays as a Defoliant in ‘Niagara Rosada’ Vine Subjected to Two Crop Production Per Year

Abstract

-In climate region Cwa of the State of São Paulo the technique of double cropping the grapevine is possible, however, when it is time for the second pruning of the crop, most of the vine's leaves are still in the plant, posing the problem that the use of ethephon as a defoliant could increase leaf senescence and improve the vine management. The objective of this study was to evaluate the effects of ethephon spray as a defoliant in the development and production of the 'Niagara Rosada' vine when subjected to double cropping, and the influence this bioactivator may have on carbohydrate reserves in the branch. The experiments were conducted in a commercial, non-irrigated area in agricultural years of 2011/2012 and 2012/2013. The length, diameter and total carbohydrate reserves of the branches, as well as bud break, number of clusters, crop production, length, width and mass of cluster, berry diameter, soluble solids and titratable acidity were evaluated. Ethephon treatments were applied at a concentration of 1,440 mg l -1 and 2,160 mg l -1 at 20 and 15 days before pruning. As a control, the vines were defoliated by hand at the time of pruning. A randomized block experimental design was used. Data was subjected to analysis of variance and means were compared by the Tukey test at 5% significance level. In conclusion, we propose that ethephon sprays promoted vine defoliation and improved the bud break, altered plant development and crop production. This was not due to increases in concentration of carbohydrate reserves in the branches, but due to a higher induction stimulus of bud break, which allowed the vines to express their higher yield capacity. Index terms: Vitis labrusca l., pruning, defoliation, carbohydrate reserves.AVALIAÇÃO DO USO DO ETEFOM COMO DESFOLHANTE NA VIDEIRA 'NIAGARA ROSADA' SUBMETIDA À PRODUÇÃO DE DUAS SAFRAS ANUAIS RESUMO-Em região de clima Cwa do Estado de São Paulo a técnica de colheita de duas safras de uva por ano é possível, no entanto, no momento da realização da segunda poda de produção as plantas encontram-se enfolhadas, levantando a questão de que uso do etefom como desfolhante poderia aumentar a senescência e melhorar o manejo da cultura. O objetivo do trabalho foi avaliar o efeito do etefom como desfolhante no desenvolvimento e produção da videira 'Niagara Rosada' quando submetida a duas safras, e a influência que esse bioativador pode ter no teor de carboidratos presentes nos ramos. O experimento foi conduzido em área comercial em videiras não irrigadas nos anos agrícolas de 2011/2012 e 2012/2013. O comprimento, diâmetro e teor de reservas de carboidratos totais dos ramos, brotação, número de cachos, produção, comprimento, largura e massa dos cachos, diâmetro de bagas, teor de sólidos solúveis e acidez titulável. Os tratamentos de etefom foram aplicados nas concentrações de 1.440 mg l -1 e 2.160 mg l -1 ,20 e 15 dias antes da poda de produção e, como tratamento testemunha foi realizada a desfolha manual no momento da poda. O delineamento estatístico foi em blocos casualizado...

Effect of new generation bio-regulators on anthocyanins and berry quality of grape cv. Beauty Seedless

“…The TSS of the berries was significantly enhanced with application of ethephon 400 ppm (20.03ºBrix) and ABA 200 ppm (19ºBrix) in comparison with the control (16.03ºBrix) (Table 2). Few other workers have also reported improvement in TSS by the use of these bioregulators such as ethephon (De Souza et al 2015;Costa et al 2016 ), ABA (Balint andReynolds 2013 andWilliams 2017), which supported the present findings. The least titratable acidity was recorded with ethephon 200 ppm (0.29%); however, ethephon 400 ppm (22.89 mg/100 ml) and ABA 400 ppm (22.01 mg/100 ml) treatments resulted in significant improvement in ascorbic acid content (Table 2).…”

Unraveling the pathways influencing the berry color and firmness of grapevine cv. Flame Seedless treated with bioregulators using biochemical and RNA-Seq analysis under semi-arid subtropics

“…In the present study, all the PBRs increased the berry TSS where ethephon 400 ppm and ABA 400 ppm produced the maximum TSS in berries. A few other studies have documented improvements in TSS due to using these PBRs, such as ethephon ( Costa et al, 2016 ) and ABA ( Balint and Reynolds, 2013 ). In the current investigation, all PBRs for TA produced varying outcomes.…”