Excessive nitrogen supply and shoot trimming can impair colour development in Pinot Noir grapes and wine

Abstract

We investigated the effects of nitrogen supply and shoot trimming on mature, field-grown Pinot Noir (Vitis vinifera L.) vines. Ammonium nitrate (0, 30, 60, 90 kg N/ha) was applied at the beginning of flowering. Shoots were topped either once (at fruit set), or twice, (at fruit set and during the lag-phase of berry growth). Neither treatment affected grape berry and skin weights, yield and grape sugar, but high rates of nitrogen increased malic acid and reduced skin phenols, flavonols and anthocyanins. Malvidin-3-glucoside was the most abundant anthocyanin in skins and wine. It accounted for 75% of the total anthocyanins at the beginning of fermentation and its relative proportion increased to 95% in the finished wine.Increases in anthocyanin concentration at the beginning of fermentation and before malolactic fermentation, were followed by declines during the later stages of alcoholic and malolactic fermentation. High nitrogen supply decreased anthocyanins in the juice and wine, increased pH and increased the percentage of malvidin-3-glucoside. Repeated shoot topping gave lower wine total phenols and anthocyanins and thus enhanced the nitrogen effect. Wine susceptibility to oxidation increased with higher pH and lower anthocyanin content. The best treatment combination for fruit and wine quality, in terms of colour and oxidative stability, was low nitrogen/single topping and the worst combination was high nitrogen/repeated topping. These results suggest that a combination of high rates of nitrogen fertiliser and repeated shoot trimming can decrease potential fruit and wine quality. Abbreviations N nitrogen; ST single topping; RT repeated topping; HPLC high performance liquid chromatography;MLF malolactic fermentation.

Aplicação de nitrogênio em videiras na Campanha Gaúcha: produtividade e características químicas do mosto da uva

“…Por outro lado, a aplicação de N aumentou de forma linear o peso das bagas de uva (Tabela 1) e isso pode ser atribuído, em geral, ao aumento da relação polpa/casca da baga, o que esta associado à diminuição dos valores de importantes compostos responsáveis pela coloração do mosto e do vinho, entre os quais as antocianas, como observado na tabela 2 e relatado por KELLER & HRAZDINA (1998) e KELLER et al (1999).…”

“…Entretanto, com a ampliação de fronteiras agrícolas, áreas de campo natural da Campanha Gaúcha foram incorporadas ao sistema de produção de uvas. Nessas áreas, a videira passou a ser cultivada em solos com textura arenosa e com baixo teor de matéria orgânica, tendo pequena capacidade de suprimento de N. Assim, a aplicação de N passou a ser uma prática de manejo necessária, já que este nutriente tem efeito na produção de uva (GOLDSPINK & GORDON, 1991;BELL & ROBSON, 1999) e nas características químicas da uva e do seu mosto, afetando os teores de sólidos solúveis totais, de pH, de acidez, de ácidos orgânicos, de polifenóis totais, de antocianas e de nutrientes (OUGH et al, 1968;BELL, 1991;BERTRAND et al, 1991;SMART, 1991;SPAYD et al, 1994;SPAYD et al, 1995;KELLER & HRAZDINA, 1998;KELLER et al, 1998;KELLER et al, 1999;KELLER, 2005).…”

Effect of nitrogen and potassium fertilization on productivity and fruit quality of ‘crimson seedless’ grape

“…In these plots high level of K (330 kg K 2 O /ha) increased concentration of anthocyanins during 2004 and 2005. Several authors anthocyanin content, whereas K improves color [29,[47][48][49]18].…”

“…Application of N and K had a direct effect on grape's bud production [1]. Considering the importance of N fertilization for color of berries, excessive nitrogen levels to vine delayed ripening [2] and poorly colored fruit [3,4]. It increased vegetative growth, which competes with sugar translocation and pigment accumulation to the berry.…”

Estado nutricional, vigor e produção em videiras cultivadas com plantas de cobertura

“…Com isso, pode acontecer incremento do teor de N total nas folhas das videiras (BRUNETTO et al, 2007;MAFRA et al, 2011;BRUNETTO et al, 2012) e crescimento vegetativo excessivo. Assim, esperase menor incidência de luz no interior do dossel, favorecendo o aparecimento de doenças fúngicas e diminuindo o número de flores fecundadas, o que resulta em menor número de bagas por cacho, retarda a senescência das folhas e o processo de dormência dos ramos, e afeta negativamente a composição da uva e de seu mosto (KELLER et al, 1999;DUCHÊNE et al, 2001;BRUNETTO et al, 2008).…”