Damage by radiative frosts is a major limiting factor for coffee cultivation in southern Brazil (south of 20 ° S latitude). The use of Mimosa scabrella (bracatinga) as a shade tree, to modify the local energy balance and thus prevent damage to the coffee plants, has been evaluated from 1986 to 1994. The study was carried out near Londrina, Parana State (23023 ' S, 51°11' W). During the experimental period, several radiative frosts with intensity ranging from moderate to very severe occurred at the site, Minimum coffee leaf temperatures during these events were 2 to 4 °C higher in the shaded plots. Due to frost protection, coffee bean yields on the average of 7 harvests were higher on the shaded plots. The potential of this system for frost protection in southern Brazil is discussed.
Dual inoculation of Casuarina sp. with arbuscular mycorrhizal fungi (AMF) and Frankia actinomycetes is typically intended to improve seedlings survival and to increase growth in degraded and low fertility soils and to replace fertilizers in low-input agricultural systems. Thus, this field study was conducted to evaluate the effects of inoculating seedlings of Casuarina cunninghamiana with mycorrhizal fungi and Frankia on tree growth on a sandy soil (Oxisol) managed with mineral fertilisation and inter-row cultivation of cover crops during 75 months. The following treatments were applied to seedlings of C. cunninghamiana: 1) inoculation with a mixture of two Frankia sp. strains (KB5 and HFPCcI3) plus AMF (Glomus clarum and Gigaspora margarita); 2) inoculation with a mixture of Frankia strains (KB5 and HFPCcI3); 3) inoculation with AMF; 4) mineral N and 5) control (no inoculated and without mineral N). Fertilization with N in the nursery improved tree height from 3 to 50 months. Diameter and wood volume were favoured by N at 10 and 17 months. Inoculation of C. cunninghamiana seedlings with Frankia showed a positive effect on height growth at 36 and 50 months. AMF and AMF plus Frankia had no effect in DBH and wood volume growth of C. cunninghamiana. This study points out the possibility of inoculation of C. cunninghamiana with selected Frankia for wood production in sandy soils managed with mineral fertilisation and inter-row cultivation of cover crops.
Embora comum em diversos países, a arborização de cafezais não é utilizada extensivamente nas principais regiões produtoras no Brasil. A redução de produtividade devido ao sombreamento excessivo proporcionado pelas árvores é apontada como a razão principal para a não adoção dessa prática. Entretanto, alguns resultados experimentais a favor da arborização de cafezais têm sido registrados. Entre os benefícios da arborização, a proteção contra geadas de radiação é considerado o mais importante, pois a ocorrência de geadas é a principal limitação da cafeicultura no Paraná. Neste trabalho foi avaliada a arborização com bracatingas em duas densidades de plantio na produtividade dos cafeeiros, durante o biênio 2002-2003. Os resultados mostraram redução estatisticamente significativa da produtividade nos tratamentos arborizados, em relação à produtividade dos cafeeiros a pleno sol, com intensidade proporcional à densidade de arborização. A proteção contra geadas de radiação foi avaliada pela diferença entre as temperaturas mínimas das folhas dos cafeeiros nos tratamentos arborizados e a pleno sol em noites com intensa perda radiativa. Em comparação com os cafeeiros a pleno sol, foram registradas temperaturas mais altas nas folhas dos cafeeiros arborizados durante as horas mais frias do dia. Concluiu-se que a arborização com bracatingas permite proteção contra geadas de radiação a partir do primeiro ano de idade. Shading coffee with bracatinga (Mimosa scabrella Bentham) trees Abstract Although common in many countries, shading coffee is not a frequent practice in Brazil. The reduction in productivity caused by excessive shade is the main reason for avoiding this practice. However, some favorable experimental results of shading coffee have been obtained. Among the benefits of shade trees for coffee production systems, radiative frost protection is considered the most important since frosts is the main constraining factor assessing coffee production in southern Brazil. In this paper, the productivity of coffee shaded with bracatinga trees grown at two densities were compared along the biennium 2002-2003. The results showed significant reduction in coffee bean productivity wich was proportional to shade tree densities. The frost protection effect was evaluated by the difference in minimum temperature of coffee leaves among the experimental treatments during selected nights with intense radiative loss. The coffee leaf temperature in shaded plots were higher than in the plots with no shelter trees during the coldest hours of the day. The results indicated that bracatinga trees may protect coffee plants against radiative frosts from one year after planting.
A Grevillea robusta é uma espécie arbórea nativa das regiões subtropicais costeiras da Austrália. Foi uma das primeiras plantas da Austrália cultivada fora de sua área de ocorrência natural, principalmente como ornamental. Essa espécie é recomendada para plantio nas regiões mais quentes do Paraná, sendo apreciada para arborização de lavouras de café. Com o objetivo de comparar o desempenho de procedências de G. robusta, instalou-se um experimento no município de Londrina, PR. Quatro procedências australianas foram fornecidas pela Divisão Florestal da CSIRO (Commonwealth Scientific and Industrial Research Organization) e a procedência local foi coletada no município de Cianorte, PR. Aos 10 anos de idade, a produção volumétrica dos materiais importados foi superior à do material local em 68,5%, 61,2%, 50,6% e 39,7% para as procedências Boyd, Woodenbong, Wivenhoe e Emu Vale, respectivamente. Todas as procedências australianas apresentaram crescimento superior ao da fonte local comercial. A procedência Wivenhoe se destacou pelo crescimento em altura, enquanto a procedência Boyd apresentou maior crescimento diamétrico e em volume. Conclui-se que a substituição das fontes de sementes disponíveis comercialmente no Paraná por sementes de procedências selecionadas pode aumentar a produtividade de Grevillea robusta na região norte do Paraná.Palavras-chave: Grevillea robusta; teste de procedências; cultivos florestais. AbstractGrowth performance of Grevillea robusta provenances in northern Parana. Grevillea robusta, a native species of subtropical coastal areas of Australia, is successfully cultivated in several countries. It is recommended for planting in warmer regions of Paraná where it is the favourite species for intercropping with coffee. A trial established in Londrina County, Paraná state, aimed to compare growth performance in relation to different provenances of G. robusta. Among the tested provenances, there were four of them provided by CSIRO’s Division of Forestry and Forest Products and one provided by a local source, from Cianorte County, provided by Paraná State Environmental Institute. Ten years after field planting, wood volume produced by Australian provenances were 68.5%, 61.2%, 50.6% and 39.7% higher than that of the local seed source (respectively Boyd, Woodenbong, Wivenhoe and Emu Vale provenances). Wivenhoe provenance attained the highest height growth and Boyd provenance the best growth in diameter and volume. This suggests that productivity growth can be achieved by seed source replace.Keywords: Grevillea robusta; provenance trial; tree plantings.
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