Adubos e coberturas orgânicas, fontes de nutrientes de liberação lenta na produção de acelga de colheitas múltiplas / Fertilizers and organic covers, slow release nutrient sources in the production of multiple harvest Swiss chard

Objetivou-se avaliar o desempenho de coberturas e adubos orgânicos na estabilidade produtiva da acelga. O delineamento experimental foi de blocos casualizados, em arranjo fatorial e em parcelas subdivididas; usando húmus de minhoca (A1), guano de ilha (A2), e húmus de esterco de porquinho-da-índia (A3) como adubos, serragem de pinheiro-de-folhas-pêndulas (C1), casca de arroz (C2), e palha de aveia (C3) como coberturas, para três colheitas sucessivas. Avaliou-se, porcentagem de emergência (E), comprimento de folhas (CF), massa fresca de folhas (MFF) e massa seca de folhas (MSF). Nos resultados, as coberturas que propiciaram os maiores valores foram a C2 e C3 com 43,1 e 42,7 cm no CF, 209,9 e 215,5 g no MFF, respectivamente; nos adubos, o A3 proporcionou os maiores valores com 92,0% na E, 44,2 cm no CF, 231,6 g no MFF, e 154 g no MSF. As coberturas de C2 e C3 e, o adubo de A3 condicionaram os melhores desempenhos no CF e MFF em relação aos outros tratamentos; os rendimentos mantiveram-se na 1ª e 2a colheita baixando significativamente na 3a colheita; o húmus de esterco de porquinho-da-índia apresenta caraterísticas nutricionais destacáveis para seu uso na horticultura.

The objective of this study was to evaluate the performance of organic coverage and fertilizers on the production stability of Swiss chard. The experimental design was randomized blocks, in factorial arrangement and subdivided plots; using earthworm humus (A1), island guano (A2), and guinea pig manure (A3) as fertilizers, pine-leaf-sawdust (C1), rice husk (C2), and oat straw (C3) as covering, for three successive harvests. Percentage of emergence (E), length leaf (CF), fresh mass (MFF) weight, and dry mass (MSF) weight were evaluated. In the results, the coverages that provided the highest values were C2 and C3 with 43.1 and 42.7 cm in the CF, 209.9 and 215.5 g in the MFF, respectively; in fertilizers, A3 provided the highest values with 92.0% in E, 44.2 cm in CF, 231.6 g in MFF, and 154 g in MSF. The C2 and C3 coverages and the A3 fertilizer conditioned the best performances in the CF and MFF in relation to the other treatments; the yields remained in the 1st and 2nd harvest, dropping significantly in the 3rd harvest; humus from guinea pig manure presented detachable nutritional characteristics for use in horticulture.

Adubos e coberturas orgânicas, fontes de nutrientes de liberação lenta na produção de acelga de colheitas múltiplas / Fertilizers and organic covers, slow release nutrient sources in the production of multiple harvest Swiss chard

Objetivou-se avaliar o desempenho de coberturas e adubos orgânicos na estabilidade produtiva da acelga. O delineamento experimental foi de blocos casualizados, em arranjo fatorial e em parcelas subdivididas; usando húmus de minhoca (A1), guano de ilha (A2), e húmus de esterco de porquinho-da-índia (A3) como adubos, serragem de pinheiro-de-folhas-pêndulas (C1), casca de arroz (C2), e palha de aveia (C3) como coberturas, para três colheitas sucessivas. Avaliou-se, porcentagem de emergência (E), comprimento de folhas (CF), massa fresca de folhas (MFF) e massa seca de folhas (MSF). Nos resultados, as coberturas que propiciaram os maiores valores foram a C2 e C3 com 43,1 e 42,7 cm no CF, 209,9 e 215,5 g no MFF, respectivamente; nos adubos, o A3 proporcionou os maiores valores com 92,0% na E, 44,2 cm no CF, 231,6 g no MFF, e 154 g no MSF. As coberturas de C2 e C3 e, o adubo de A3 condicionaram os melhores desempenhos no CF e MFF em relação aos outros tratamentos; os rendimentos mantiveram-se na 1ª e 2a colheita baixando significativamente na 3a colheita; o húmus de esterco de porquinho-da-índia apresenta caraterísticas nutricionais destacáveis para seu uso na horticultura.(AU)

The objective of this study was to evaluate the performance of organic coverage and fertilizers on the production stability of Swiss chard. The experimental design was randomized blocks, in factorial arrangement and subdivided plots; using earthworm humus (A1), island guano (A2), and guinea pig manure (A3) as fertilizers, pine-leaf-sawdust (C1), rice husk (C2), and oat straw (C3) as covering, for three successive harvests. Percentage of emergence (E), length leaf (CF), fresh mass (MFF) weight, and dry mass (MSF) weight were evaluated. In the results, the coverages that provided the highest values were C2 and C3 with 43.1 and 42.7 cm in the CF, 209.9 and 215.5 g in the MFF, respectively; in fertilizers, A3 provided the highest values with 92.0% in E, 44.2 cm in CF, 231.6 g in MFF, and 154 g in MSF. The C2 and C3 coverages and the A3 fertilizer conditioned the best performances in the CF and MFF in relation to the other treatments; the yields remained in the 1st and 2nd harvest, dropping significantly in the 3rd harvest; humus from guinea pig manure presented detachable nutritional characteristics for use in horticulture.(AU)

The diversity, extracellular enzymatic activities and photoprotective compounds of yeasts isolated in Antarctica

The diversity of yeasts collected from different sites in Antarctica (Admiralty Bay, King George Island and Port Foster Bay and Deception Island) and their ability to produce extracellular enzymes and mycosporines were studied. Samples were collected during the austral summer season, between November 2006 and January 2007, from the rhizosphere of Deschampsia antarctica, ornithogenic (penguin guano) soil, soil, marine and lake sediments, marine water and freshwater from lakes. A total of 89 isolates belonging to the following genera were recovered: Bensingtonia, Candida, Cryptococcus, Debaryomyces, Dioszegia, Exophiala, Filobasidium, Issatchenkia (Pichia), Kodamaea, Leucosporidium, Leucosporidiella, Metschnikowia, Nadsonia, Pichia, Rhodotorula, and Sporidiobolus, and the yeast-like fungi Aureobasidium, Leuconeurospora and Microglossum. Cryptococcus victoriae was the most frequently identified species. Several species isolated in our study have been previously reported to be Antarctic psychophilic yeasts, including Cr. antarcticus, Cr. victoriae, Dioszegia hungarica and Leucosporidium scottii. The cosmopolitan yeast species A. pullulans, C. zeylanoides, D. hansenii, I. orientalis, K. ohmeri, P. guilliermondii, Rh. mucilaginosa, and S. salmonicolor were also isolated. Five possible new species were identified. Sixty percent of the yeasts had at least one detectable extracellular enzymatic activity. Cryptococcus antarcticus, D. aurantiaca, D. crocea, D. hungarica, Dioszegia sp., E. xenobiotica, Rh. glaciales, Rh. laryngis, Microglossum sp. 1 and Microglossum sp. 2 produced mycosporines. Of the yeast isolates, 41.7% produced pigments and/or mycosporines and could be considered adapted to survive in Antarctica. Most of the yeasts had extracellular enzymatic activities at 4ºC and 20ºC, indicating that they could be metabolically active in the sampled substrates.