Ação do cepa e do ácido giberélico na frutificação da videira 'niagara rosada'

Studies were carried out to establish the effects of exogenous growth regulators on Vitis (labrusca x vinifera) 'Niagara Rosada' fruiting. The investigations were done in the Jundiaí Research Station, Agronomic Institute State of São Paulo, always using disease-free vineyards of good productivity. The morphological transformations of clusters were carried out under the following aspects: weight, length and width of cluster; number of berries; weight, length average and width average of berries; length average/width average ratio of berries; number of seeds; length and diameter of secondary rachis. That characteristics were determined at the time of maturity plus the total sugars, total acid, Maturity Index and reducing sugars in samples of all treatments. The experiment were conduced in order to determine the doses that resulted in the most beneficial effects, always using applications by immersion of the inflorescence. The experiment consisted of appplications of (2-chloroethyl) phosphonic acid (CEPA) at concentrations of 50, 100, 250, 500, 1,000 and 2,000 ppm, 14 days before flowering; treatments with gibberellic acid at concentrations of 100 and 200 ppm before full bloom, 10 days after full bloom, and both before plus after full bloom. Treatment with CEPA 100 ppm plus gibberellic acid 100 ppm before full bloom and check treatment were also used. The use of CEPA before flowering at the concentrations used, did not result in good results in 'Niagara Rosada' clusters; applications of gibberellic acid did not differ significantly from the nontreated vines under the conditions studied.Estudou-se o efeito da aplicação, por imersão, do CEPA (ácido 2-cloroetil fosfônico) e do ácido giberélico, 14 dias antes do florescimento, nas características morfológicas da panícula da videira Vitis (labrus-ca x vinifera) "Niagara Rosada". Alguns tratamentos com ácido giberélico foram concluídos com nova aplicação 10 dias após o florescimento. Neste experimento verificou-se que, aplicação do CEPA na concentração de 250 ppm resultou na formação de panículas com a maioria de características indesejáveis. o tratamento misto CEPA 100 ppm + ácido giberélico 100 ppm também promoveu o aparecimento de panículas subdesenvolvidas. Aplicação de ácido giberélico na concentração de 100 ppm em pré e pós-ílorescimento, resultou médias mais elevadas, com relação ao peso da panícula, comprimento da panícula, peso das bagas e comprimento da ráquis. Ácido giberélico na concentração de 100 ppm aplicado em pós-ílorescimento, promoveu uma tendência de aumento nas médias do tratamento quanto ao comprimento médio das bagas, largura média das bagas, largura do engaço e comprimento da ráquila. Devemos considerar porém, que os resultados obtidos não apresentaram diferenças significativas com relação ao controle, quanto às características das frutificações, nas condições de estudo

Grapevine salt tolerance

Salinity, which is predominantly an issue for agricultural systems in arid and semi-arid regions, has the potential to impair grape production and wine quality, and its impact on the grape and wine industries is predicted to increase with climate change. Research on the physiological and molecular changes that occur in salt-affected vines has unveiled complex osmotic and ionic responses that include oxidative stress, water loss, photoinhibition, growth inhibition and necrosis. Proposed salt tolerance mechanisms include elevated antioxidant production, hydric regulation and salt exclusion from shoots and berries. These later of these mechanisms is found in certain Vitis genotypes that, when grafted as rootstocks, can protect fruit-bearing scions from accumulating significant amounts of saline ions from soils, most notably through the presence of specific transport proteins that are involved in regulating the transfer of ions from root to shoot via the xylem. Significant gaps in knowledge remain, however, regarding salt tolerance mechanisms for Vitis species, with many mechanisms inferred from other species or documented only at the level of gene expression. A better understanding of the mechanisms that confer salt tolerance in Vitis species is needed to improve the production of new germplasm that is locally adapted and better suited to the challenges of a changing climate. Hence, this review covers the current knowledge on the characteristics that are associated with salt damage and tolerance in grapevine cultivars and rootstocks and highlights possible future avenues that will enable development of new options for the industry to combat salinity.A. Zhou-Tsang, Y. Wu, S.W. Henderson, A.R. Walker, A.R. Borneman, R.R. Walker and M. Gilliha