Photosynthetic capacity of 'Niagara Rosada

http://dx.doi.org/10.1590/0103-8478cr20150400 Ciência Rural, Santa Maria, v.46, n.6, p.950-956, jun, 2016 Rosada grapes grown under transparent Photosynthetic capacity of Niagara plastic covering. 950 ISSN 1678-4596 CROP PRODUCTION Photosynthetic capacity of ‘Niagara Rosada’ grapes grown under transparent plastic covering Capacidade fotossintética da videira ‘Niagara Rosada’ cultivada sob cobertura plástica transparente Bruna Corrêa da Silva de DeusI Fábio Afonso Mazzei Moura de Assis FigueiredoII Luciana Venturotti Braun de AlmeidaI Tiago Massi FerrazII Amanda Oliveira MartinsI Weverton Pereira RodriguesI Leandro Hespanhol VianaI Barbara dos Santos EstevesI Eliemar CampostriniI* ABSTRACT New techniques in tropical regions such as use of transparent plastic covering (TPC), have been employed in grapes to avoid the wetting leaves and fruits, which can reduce the occurrence of fungal diseases, reduce the use of sprays, and reduce damage caused by hail and high winds. TPC may significantly affect the photosynthetic rates of grapevines cultivated in tropical regions, and thus have strong effects on plant productivity and improve fruit quality. However, in the North of Rio de Janeiro region there are lacks of studies related to TPC effects on photosynthetic capacity. The objective of this study was to evaluate the photosynthetic capacity in ‘Niagara Rosada’ vines grown under TPC and without transparent plastic covering (WTPC). The experiment was conducted between April and June 2013, on Tabuinha farm, located in the 3rd district of São Fidélis, Rio de Janeiro State, Brazil. A completely randomized block design was used with two treatments (TPC and WTPC) and twelve replications. Evaluations consisted of climatological variables, gas exchange and maximum quantum efficiency of open photosystem II centers-quantum yield (Fv/Fm) It was possible to observe that under TPC maximum temperature increase of 2.3°C, relative humidity reduced 1.5%, vapor pressure deficit increase 0.4kPa, and light intensity reduced 47.7%. These changes did not cause photochemical damage to the leaves. The TPC promoted higher net photosynthetic rate at 800h, which was associated with higher stomatal conductance. Thus, the TPC used in the northern region of Rio de Janeiro State did not impair the photosynthetic capacity of ‘Niagara Rosada’ vines. Key words: photosynthesis, chlorophyll fluorescence, Vitisla brusca, covered system. RESUMO A cobertura plástica tem sido utilizada com a finalidade de evitar os efeitos negativos do molhamento foliar sobre a incidência de doenças em videiras ‘Niagara Rosada’, reduzir a aplicação de defensivos agrícolas e, dessa maneira, melhorar a qualidade dos frutos. Contudo, na região Norte Fluminense, não se tem estudos relacionados aos efeitos do uso da cobertura plástica na assimilação fotossintética do carbono e na eficiência fotoquímica associada ao fotossistema II (PSII) dessa espécie. O objetivo deste experimento foi avaliar a capacidade fotossintética em videiras ‘Niagara Rosada’ cultivadas sob cobertura plástica e sem cobertura plástica no Norte Fluminense. O experimento foi realizado entre abril e junho de 2013, no sítio Tabuinha, localizado no 3o distrito do município de São Fidélis, RJ. O delineamento experimental utilizado foi inteiramente casualizado com 2 tratamentos, com cobertura plástica e sem cobertura plástica, e 12 repetições. As avaliações foram relacionadas às variáveis climáticas, às trocas gasosas e ao rendimento quântico máximo do fotossistema II. Nesta pesquisa, sob a cobertura plástica, foi possível observar a elevação no valor da temperatura máxima do ar em 2,3ºC, redução na umidade relativa em 1,5%, incremento no déficit de pressão de vapor do armax em 0,4kPa, e redução na intensidade luminosa em 47,7%. Essas alterações não causaram comprometimento na eficiência fotoquímica das folhas. O sistema com cobertura plástica promoveu maior taxa fotossintética líquida (A) pela manhã (8h), e este aumento em A foi associado à maior condutância estomática nesse horário. Neste trabalho, a cobertura plástica utilizada não causou comprometimentos na capacidade fotossintética da videira ‘Niagara Rosada’. Palavras-chave: fotossíntese, fluorescência da Vitislabrusca, sistema coberto. clorofila, INTRODUCTION Brazil is currently in 12th position on the list of grape producing countries (FAOSTAT, 2014). Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Av. Alberto Lamego, 2000, 28013-602, Campos dos Goytacazes, RJ, Brasil. E-mail: . *Corresponding author. II Departamento de Química e Biologia, Universidade Estadual do Maranhão (UEMA), Imperatriz, MA, Brasil. I Received 03.17.15 Approved 11.03.15 Returned by the author 02.06.16 CR-2015-0400.R3 Ciência Rural, v.46, n.6, jun, 2016. 951 de Deus et al. In recent years the Brazilian consumption of in natura grapes has grown and because of this an increase in the cultivated area and a greater use of technology in grape cultivation has been observed leding to significant increases in yield (IBGE, 2011). One of the techniques employed in vine cultivation is transparent plastic covering (TPC) over the plants, using wooden structures with a special transparent plastic covering. TPC can minimizes the damaging effects of temperature, wind and rain on the leaves and fruit (CHAVARRIA et al., 2010). These damaging effects in general are caused by hail and strong winds, or by the occurrence of diseases due to leaf wetting (CHAVARRIA et al., 2007). TPC can be used both on grapes destined for wine production (SILVA et al., 2008) and on grapes destined for in natura consumption, known as table grapes (LULU et al., 2005). Effects of using TPC on yield and vine fruit quality have been studied in some regions such as Minas Gerais, where the effects were assessed on cycle length and changes in development on shaded vines (FERREIRA et al., 2004), and in Rio Grande do Sul state, where COMIRAN et al. (2012) assessed the development and production on organics vines grown under TPC. The north and northeast of the state of Rio de Janeiro is a region that is becoming important in table grapes cultivation, where favorable environmental conditions can be found for the cultivation of this species, such as abundant water, suitable air temperatures and solar radiation considered as optimal levels. Increase in the planted area and consequently in yield have allowed fruit of the species to be supplied to grocery stores in the region. However, there are few studies on this region concerning the effect of plastic cover on the photosynthetic capacity. Among the cultivars, ‘Niagara Rosada’, derived from a natural somatic mutation of the cultivar ‘Niagara Branca’ (POMMER et al., 1997) has been outstanding to date, with high economic interest because it is a specie for in natura consumption as a table grape. The objective of the present research was to assess the responses in the pho (...truncated)