Calagem como amenizante da toxidez de cobre em aveia preta (Avena strigosa) e em videiras jovens (Vitis sp.)

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Agroecossistemas, Florianópolis, 2015.As sucessivas aplicações de fungicidas à base de Cu em vinhedos causam o acúmulo do metal pesado no solo. O Cu é um nutriente essencial às plantas, porém, o seu excesso pode provocar sintomas de toxidez, como danos nas raízes, inibição da absorção de nutrientes e do crescimento das plantas. Em vinhedos, os sintomas de toxidez de Cu podem ser observados em videiras jovens recém transplantadas e em plantas de cobertura do solo, como a aveia preta. A toxidez de Cu nas videiras pode retardar o início do seu período produtivo, gerando prejuízos econômicos; em plantas de cobertura do solo pode reduzir a biomassa ou mesmo haver a morte das plantas, deixando o solo descoberto, o que se reflete em menor ciclagem de nutrientes e maior potencial de erosão. Todavia, os efeitos tóxicos do Cu podem ser amenizados pela calagem, normalmente realizada na implantação do vinhedo. O trabalho objetivou avaliar: (a) o efeito da calagem como amenizante da toxidez de Cu em aveia preta cultivada em solo com textura arenosa; (b) o efeito da calagem como amenizante da toxidez de Cu em videiras jovens cultivadas em solo com textura arenosa. Para isso, foram realizados dois estudos. Em ambos, os tratamentos consistiram da adição no solo de doses crescentes de calcário (0,0, 1,5 e 3,0 Mg ha-1) e duas de Cu (0 e 50 mg kg-1). No Estudo 1, cultivaram-se plantas de aveia por 30 dias e, posteriormente, avaliou-se altura das plantas, massa seca de raízes e parte aérea, teor e acúmulo de nutrientes nas raízes e na parte aérea, teor de clorofilas a, b e total, carotenoides, e carboidratos solúveis e amido totais. No Estudo 2, cultivaram-se videiras jovens ?Niágara Branca? por 70 dias e, posteriormente, avaliaram-se o diâmetro, área do córtex e do cilindro vascular, número de camadas do córtex e de células contendo compostos fenólicos nas raízes, matéria seca de raízes, caule e folhas, incremento em altura, teor e acúmulo de Cu, Ca e Mg nas raízes, caule e folhas. A dose de 50 mg kg-1 de Cu no solo inibiu o crescimento da aveia preta, afetou a distribuição interna dos nutrientes, reduziu a concentração de clorofila e aumentou os teores de carboidratos solúveis e amido totais nas folhas; e, nas videiras jovens, afetou a estrutura das raízes, inibiu o crescimento, reduziu o teor de Ca e incrementou o teor e a porcentagem de Cu acumulado nas raízes das plantas. Considerando um cultivo con-comitante de aveia preta e de videiras jovens em uma área de vinhedo com um solo com características semelhantes ao utilizado no presente estudo, a dose de 3,0 Mg ha-1 de calcário seria a mais adequada para amenizar os efeitos de toxidez de Cu e permitir o bom crescimento e desenvolvimento das duas espécies.Abstract : Successive applications of Cu-based fungicides in vineyards lead to the accumulation of heavy metal in the soil. Cu is an essential nutrient to plants, but it can cause symptoms of toxicity when in excess, such as damage in roots, inhibition of nutrient uptake and plant growth inhibition. In vineyards, the symptoms of Cu toxicity can be observed in young newly transplanted vines and cover crops such as oats. Cu toxicity in the vines may delay the onset of their productive period, generating economic losses; in cover crops may reduce biomass or even the plant death, leaving the soil uncovered, causing less nutrient cycling and increased potential for erosion. However, liming, usually held in vineyard deployment, can ameliorate the toxic effects of Cu. The study aimed to evaluate: (a) the effect of liming as a Cu-toxicity ameliorator in black oat grown in soil with sandy texture; (b) the effect of liming as a Cu-toxicity ameliorator in young vines grown in soil with sandy texture. For this, two studies were conducted. In both studies, the treatments consisted of soil supplementation with increasing doses of lime (0.0, 1.5 and 3.0 Mg ha-1) and two doses of Cu (0 and 50 mg kg-1). In Study 1, oat plants were grown for 30 days and, subsequently, the plant height, root and shoot dry mass, levels of a, b and total chlorophyll, carotenoids, soluble carbohydrates and total starch were assessed. In Study 2, young vines 'Niagara Branca? were grown for 70 days and, subsequently, diameter, cortex and vascular cylinder areas, number of cortical layers and of cells containing phenolic compounds in roots, dry matter of roots, stems and leaves, height increment, content and accumulation of Cu, Ca and Mg in the roots, stems and leaves were assessed. The dose of 50 mg kg-1 Cu in the soil inhibited black oat growth, affected the internal distribution of nutrients, decreased the chlorophyll concentration and increased the levels of total soluble carbohydrates and starch in leaves; and, in young vines, it affected the root structure, inhibited plant growth, decreased the Ca content and increased the content and the percentage of Cu accumulated in roots. Considering a concomitant cultivation of black oat and young vines in a vineyard area with a soil with similar characteristics to that used in the present study, the dose of 3.0 Mg ha-1 of lime is the most appropriate to mitigate the effects of toxicity Cu and allow good growth and development of both species

Nutritional status, yield and composition of peach fruit subjected to the application of organic compost

ABSTRACT. The purpose of this study was to evaluate the nutritional state, yield and composition of peaches on peach trees subjected to the application of organic compost to the soil. This experiment was conducted during the 2008 and 2009 cropping season in an orchard containing Chimarrita cultivars grafted onto Capdeboscq rootstocks and Haplumbrept soils in the municipality of Farroupilha (Rio Grande do Sul State), Brazil. The treatments included 0, 9, 18, 36, 72 and 144 liters of organic compost per plant-1 year-1. The total nutrient contents in the leaves, yield components, yields per plant and hectare and compositions of the fruits were evaluated in 2008 and 2009 soon after harvest and after 30 days of storage. The application of organic compost to the soil increased the yield components and the yields per plant and hectare in the two treatments with the highest compost additions, which indicated that the addition of 72 L of compost per plant-1 is ideal economically. The organic compost had little effect on the composition of the peach fruit after harvest and after 30 days of storage

Teor de nitrogênio e reservas nitrogenadas em folhas e ramos do ano de macieiras submetidas à adubação nitrogenada foliar

http://dx.doi.org/10.5007/2175-7925.2012v25n4p59 As aplicações foliares de nitrogênio (N), quando necessárias, têm sido usadas para complementar a adubação de frutíferas via solo. Entretanto, informações sobre os efeitos da frequência, quantidade de N a ser aplicada, e a importância do aumento do teor de N e de suas reservas nas folhas e ramos do ano são escassas. Este trabalho teve como objetivo avaliar o efeito de aplicações foliares de N no teor e nas reservas nitrogenadas das folhas e ramos do ano em macieiras. O estudo foi conduzido em um pomar de macieira (cultivar Eva), safra 2007/08, na área experimental do Colégio Politécnico da Universidade Federal de Santa Maria (UFSM), em Santa Maria, RS, sobre um planossolo hidromórfico. Os tratamentos consistiram em 1 e 2 aplicações foliares de 0; 1,11; 2,23; 3,31; 4,41; e 5,51g de N planta-1. Os resultados mostraram que as aplicações foliares de N proporcionaram aumento nos teores de N nas folhas inteiras, especialmente até o 8º dia após a aplicação, porém, não afetam o teor de N nos ramos do ano. A adubação nitrogenada por via foliar não aumentou o teor total de aminoácidos e proteínas nas folhas inteiras e nos ramos do ano

Nitrogen content and nitrogen reserves in annual leaves and offshoots of apple trees undergoing foliar nitrogen fertilization

Foliar applications of nitrogen (N), when needed, have been used to supplement the fertilization of fruit trees through the soil. However, information on frequency effects, N amount to be applied, and the importance of increasing N content and N reserves in the leaves and offshoots are few. This paper aimed at evaluating the effect of foliar N applications on the N content and reserves in annual leaves and offshoots of apple trees. The study was carried out in an apple trees orchard (Eva cultivar), crop 2007/2008, in the experimental area of the Polytechnic College of Universidade Federal de Santa Maria (UFSM), in the town of Santa Maria, Rio Grande do Sul, Brazil, on a hydromorphic planosol. The treatments consisted of 1 and 2 foliar applications of 0; 1.11; 2.23; 3.31; 4.41; and 5.51g of N plant-1. The results showed that foliar N applications resulted in increased N contents in the whole leaves, especially up to the 8th day after application, but they do not affect N content in the annual offshoots. Nitrogen fertilization via the leaves did not increase the total content of amino acids and proteins in the annual whole leaves and offshoot

Yield and must composition of 'Cabernet Sauvignon' grapevines subjected to nitrogen application in soil with high organic matter content

ABSTRACT It is common for vineyards in regions of high altitude to have high organic matter content in soil. Furthermore, reduced miner alization of organic matter and decomposing residues is expected because of the low temperatures. Thus, soils may not provide enough mineral nitrogen (N) to meet the needs of the grapevines and so the application of N sources is necessary, but may affect yield and must composition. The study aimed to evaluate yield and must composition of grapevines subjected to N application in soil with high organic matter content and the relationship with temperature and rainfall. The study was conducted in crops sea sons 2011/12, 2012/13 and 2013/14 in a vineyard located in the city of Água Doce, state of Santa Catarina, southern Brazil. The treatments consisted of N doses (0, 20, 40, 80 and 120 kg N ha-1) supplied via urea. Leaves opposite to the cluster were collected at full flowering and at veraison. Afterwards, the leaves were dried, ground and submitted to N analysis. Parameters of yield and must composition were evaluated. The dose of maximum technical efficiency in Cabernet Sauvignon grapevines was reached with 46 kg N ha-1 year-1 in crop season 2012/13. Leaf N content was a sensitive parameter to the application of N doses in the soil and underwent seasonal variation in relation to rainfall distribution. The N doses reduced total soluble solids (TSS) contents in the must. Based on principal component analysis, we found a correlation between total N content in leaf and accumulated rainfall, as well as between yield and temperature.RESUMEN Los viñedos ubicados en regiones altas poseen suelos con alto contenido de materia orgánica. Sin embargo, debido a la baja temperatura se espera menor mineralización de la materia orgánica. De esta forma, los suelos pueden proporcionar menos cantidad de nitrógeno (N) mineral, respecto a los requerimientos de la vid. Por eso, es necesaria la aplicación de nitrógeno que puede afectar la productividad de la vid y la composición de la uva. Este estudio tuvo como objetivo evaluar la productividad y la composición del mosto de la vid sometido a la aplicación de N en suelos con alto contenido de materia orgánica y la relación con la temperatura y la pluviometría. El estudio fue realizado durante las campañas de los años 2011/12, 2012/13 y 2013/14, en un viñedo ubicado en el municipio de Agua Doce, Santa Catarina, región sur de Brasil. Los tratamientos fueron diferentes dosis de N (0, 20, 40, 80 e 120 kg N ha-1), suministrados con urea. La dosis de máxima eficiencia técnica en la vid Cabernet Sauvignon fue alcanzada con 46 kg N ha-1 año-1 en suelos con alto contenido de materia orgánica. El contenido de nitrógeno en las hojas fue un parámetro sensible a la aplicación de dosis de N en el suelo es sensible a la distribución de las lluvias. El N reduce el contenido de sólidos solubles totales en el mosto. Con base en los principales componentes analizados, los resultados indican una correlación entre el contenido de nitrógeno total en las hojas y la precipitación acumulada, así como entre los rendimientos y la temperatura