Aspectos fisiológicos do desenvolvimento de mudas de café cultivadas sob telas de diferentes colorações

Abstract

Resumo -O objetivo deste trabalho foi avaliar aspectos fisiológicos do desenvolvimento de mudas de café, cultivadas sob telas com diferentes características espectrais. Mudas de Catucaí Amarelo 2SL, no estádio "orelha de onça", foram dispostas em blocos ao acaso, com cinco repetições, sob estruturas cobertas individualmente com telas nas cores azul, branca, cinza, preta e vermelha, com sombreamento de 50%. Quatro meses depois, foram avaliados: o crescimento das mudas, os teores de pigmentos nas folhas, e os de açúcares solúveis totais e o amido das folhas e raízes. A tela vermelha foi a mais eficiente em promover o crescimento em quatro das sete características estudadas: altura das plantas, área e massa de matéria seca foliar e massa de matéria seca total. Para as demais características, não houve diferença entre as telas. A análise dos pigmentos mostrou que, à exceção da tela cinza, as demais não diferiram entre si quanto a esta característica. Nas folhas, a tela vermelha proporcionou maior teor de açúcar e de amido. Na raiz, os teores de carboidratos foram mais elevados com as telas vermelha e preta. Entre as cinco colorações de tela, a vermelha foi a mais eficiente na produção de mudas de café com maior vigor e qualidade, em que se destacam os teores de carboidrato e a fitomassa.Termos para indexação: Coffea arabica, carboidratos, crescimento, pigmentos, qualidade da radiação, viveiro. Physiological aspects of seedling development of coffee grown under colored screensAbstract -The objective of this work was to evaluate the physiological aspects of the development of coffee seedlings grown under colored screens with different spectral characteristics. Seedlings of Catucaí Amarelo 2SL, in the stage known as "orelha de onça", were arranged in a randomized block design, with five replicates, under structures individually covered with blue, white, gray, black or red screens with 50% shade. Four months after, evaluations were done for seedling growth, pigment content of the leaves, total soluble sugars and starch contents of the leaves and roots. The red screen was the most effective in promoting growth in four out of the seven studied traits: plant height, leaf area and leaf dry weight and total dry matter. For the other characteristics, there was no difference among the screens. The pigment analysis showed that, except for the gray screen, the other ones did not differ for this trait. In leaves, the red screen promoted higher levels of carbohydrates and starch. At the root, carbohydrate contents were higher under the red and black screens. Among the five screen colors, the red one was the most efficient in the production of coffee seedlings with higher vigor and quality, with outstanding carbohydrate contents and biomass.

<b>The production of <i>Physalis</i> spp. seedlings grown under different-colored shade nets

“…Lower dry mass results in plants under blue shade nets compared with other colors were also reported by Corrêa, Pinto, Reis, and Moreira (2012) and Henrique, Alves, Deuner, Goulart, and Livramento (2011), in Origanum vulgare L. and coffee, respectively. However, the accumulation of dry biomass is related to the response of each species to the light spectrum (Brant et al, 2009) and is not standardized to the lowest and highest accumulation in a single color.…”

“…This mass accumulation is one plant response to the reduction in the intensity of quality without implementation of light quality because the black shade net only reduces the light, without converting light to the red and blue spectrum, which is theoretically more favorable for photosynthesis. High dry mass accumulation with a black shade net was also reported by Henrique, Alves, Deuner, Goulart, and Livramento (2011) in coffee seedlings, which had lower dry mass compared to the seedlings grown under a red shade net, from five luminous qualities evaluated.…”

“…); under blue screens, raffia palm (Rhapis excelsa (Thunberg) Henry ex Rehder.) and basil (Ocimum gratissimum L.); under black shade nets, the Anthurium andraeanum Lindl, or exhibit similar growth in different color screens as the case of coffee seedlings (Coffea arabica L.) (Meirelles, Paiva, Oliveira, & Tavares, 2007;Martins, Alvarenga, Castro, Pinto, & Silva, 2008;Nomura et al, 2009;Henrique, Alves, Deuner, Goulart, & Livramento, 2011;Souza, Silva, Oliveira, Santos Neto, & Santos, 2014).…”

Qualidade De Mudas De Jaracatiá Submetidas a Diferentes Períodos De Sombreamento Em Viveiro

“…O manejo da luz, tanto em qualidade (HENRIQUE et al, 2011) quanto em quantidade (TATAGIBA et al, 2010), é decisivo para o crescimento, desenvolvimento e partição de assimilados das plantas em condições de viveiro. Fonseca et al (2002), estudando o efeito do período de sombreamento sobre o padrão de qualidade de mudas de T. micrantha, determinaram as combinações mais adequadas de tempo de permanência das mudas nas condições de viveiro sombreado, e o tempo de exposição ao pleno sol leva as mudas a atingirem índices de qualidade adequados.…”

Initial growth of Bauhinia variegata trees under different colored shade nets and light conditions

“…Castro et al (2005) mention that, during its development, the leaf, which usually absorbed photoassimilates, starts to produce and translocate these compounds to other organs. However, according to Henrique et al (2011), matter allocation due to variations on the incident light is not yet fully understood. Also, according to Benincasa (2003), LAR values can be confused with the real dry matter and, as a matter of fact, this is demonstrated by the data collected from such variable in this experiment (Tables 1 and 2).…”