Root system structure as a criterion for the selection of grapevine genotypes that are tolerant to excess copper and the ability of phosphorus to mitigate toxicity.

Using tolerant genotypes and the correct use of fertilizers can mitigate the negative effect of elevated Cu levels in the growing medium. In this context, the study aimed to evaluate the effects of excess Cu in the root system and the effectiveness of phosphorus (P) in minimizing the phytotoxicity of Cu in three genotypes: IAC 572 [(Vitis riparia x V. rupestris) x V. caribaea], Magnolia (V. rotundifolia) and Paulsen 1103 (V. berlandieri x V. rupestris). The plants were grown in nutrient solutions and were supplemented with the following treatments: 0.3 µM Cu (Control), 60 µM Cu (Cu) and 60 µM Cu and 62 mg L-1 P (Cu + P). Root samples were sectioned for microscopy analyses, and the shoot lengths, shoot and root dry matter, relative growth rates (RGR) and tissue nutrient contents were also evaluated. The roots of the genotypes that were cultivated with high Cu concentrations produced greater numbers of branches and larger diameters, except for Magnolia genotype that was cultivated in a Cu + P solution, which had an organization similar to the control. Excess Cu caused accumulations of phenolic compounds and decreased shoot lengths, dry matter and RGR in the genotypes. In the treatments with excess Cu, there were increases in this element in the tissues, but P decreased the metal concentrations in Magnolia roots. Therefore, Cu accumulations alter the root system development patterns, growth parameters and tissue nutrient contents in the studied genotypes. Magnolia has a higher tolerance and is also the only genotype for which the use of P has been shown to be effective.

Grape yield and must composition of Cabernet Sauvignon grapevines with organic compost and urea fertilization / Produtividade de uvas e composição do mosto de videiras ‘Cabernet Sauvignon fertilizadas comcomposto orgânico e ureia

Urea and organic compost are applied as a nitrogen (N) source in vineyards. The aim of this study was to evaluate the yield, total N content in the leaves and the must composition in grapevines with the application of organic compost and urea. Cabernet Sauvignon grapevines, in the 2008/2009 and 2009/2010 crop seasons were subjected to the application of 40 kg N ha-1 in the form of organic compost and urea; but there were also unfertilized grapevines. In both crop seasons, leaves were collected at the stages of full flowering and at the change in color of the berries, and the total N content was analyzed; grape yield was evaluated and enological attributes were determined in the must. The application of organic compost and urea did not affect the N content in the leaf nor the grape yield in the second crop season evaluated. However, in the first crop season, grape yield was greater in the grapevines with application of organic compost on the soil. The addition of N sources did not affect the total nutrient content in the must but, in the second crop season, the grape must from the grapevines with the addition of organic compost had a lower soluble solids concentration and a higher total acidity value, as well as tartaric and malic acid values.(AU)

A ureia e o composto orgânico são aplicados em vinhedos como fonte de nitrogênio (N). O estudo objetivou avaliar a produtividade, o teor de N total em folhas e a composição do mosto em videiras submetidas à aplicação de composto orgânico e ureia. Videiras ‘Cabernet Sauvignon nas safras de 2008/2009 e 2009/2010 foram submetidas à aplicação de 40 kg de N ha-1 na forma de composto orgânico e ureia, mas videiras também não foram adubadas. Nas duas safras foram coletadas folhas no florescimento e na mudança da cor das bagas, preparadas e submetidas à análise de N total. A produção de uva foi avaliada e atributos enológicos foram determinados no mosto. A aplicação de composto orgânico e ureia não afetou o teor de N total nas folhas e a produção de uva na segunda safra avaliada. Mas, na primeira safra, a produção de uva foi maior nas videiras submetidas à aplicação com composto orgânico no solo. A adição de fontes de N não afetou o conteúdo de nutrientes no mosto mas, na segunda safra, o mosto da uva derivado das plantas com a adição de composto orgânico apresentou baixo teor de sólidos solúveis totais, maior valor de acidez, ácido tartárico e ácido málico.(AU)

Grape yield and must composition of Cabernet Sauvignon grapevines with organic compost and urea fertilization / Produtividade de uvas e composição do mosto de videiras ‘Cabernet Sauvignon’ fertilizadas comcomposto orgânico e ureia

Urea and organic compost are applied as a nitrogen (N) source in vineyards. The aim of this study was to evaluate the yield, total N content in the leaves and the must composition in grapevines with the application of organic compost and urea. Cabernet Sauvignon grapevines, in the 2008/2009 and 2009/2010 crop seasons were subjected to the application of 40 kg N ha-1 in the form of organic compost and urea; but there were also unfertilized grapevines. In both crop seasons, leaves were collected at the stages of full flowering and at the change in color of the berries, and the total N content was analyzed; grape yield was evaluated and enological attributes were determined in the must. The application of organic compost and urea did not affect the N content in the leaf nor the grape yield in the second crop season evaluated. However, in the first crop season, grape yield was greater in the grapevines with application of organic compost on the soil. The addition of N sources did not affect the total nutrient content in the must but, in the second crop season, the grape must from the grapevines with the addition of organic compost had a lower soluble solids concentration and a higher total acidity value, as well as tartaric and malic acid values.

A ureia e o composto orgânico são aplicados em vinhedos como fonte de nitrogênio (N). O estudo objetivou avaliar a produtividade, o teor de N total em folhas e a composição do mosto em videiras submetidas à aplicação de composto orgânico e ureia. Videiras ‘Cabernet Sauvignon’ nas safras de 2008/2009 e 2009/2010 foram submetidas à aplicação de 40 kg de N ha-1 na forma de composto orgânico e ureia, mas videiras também não foram adubadas. Nas duas safras foram coletadas folhas no florescimento e na mudança da cor das bagas, preparadas e submetidas à análise de N total. A produção de uva foi avaliada e atributos enológicos foram determinados no mosto. A aplicação de composto orgânico e ureia não afetou o teor de N total nas folhas e a produção de uva na segunda safra avaliada. Mas, na primeira safra, a produção de uva foi maior nas videiras submetidas à aplicação com composto orgânico no solo. A adição de fontes de N não afetou o conteúdo de nutrientes no mosto mas, na segunda safra, o mosto da uva derivado das plantas com a adição de composto orgânico apresentou baixo teor de sólidos solúveis totais, maior valor de acidez, ácido tartárico e ácido málico.