Prospecção de nematoides em hortas do município de Petrolina-PE.

O objetivo desse trabalho foi realizar a prospecção de fitonematoides em hortas comunitárias localizadas no Município de Petrolina, PE.

Carbon in humic fractions of organic matter in soil treated with organic composts under mango cultivation.

Soil organic matter (SOM) plays a key role in maintaining the productivity of tropical soils, providing energy and substrate for the biological activity and modifying the physical and chemical characteristics that ensure the maintenance of soil quality and the sustainability of ecosystems. This study assessed the medium-term effect (six years) of the application of five organic composts, produced by combining different agro-industrial residues, on accumulation and chemical characteristics of soil organic matter. Treatments were applied in a long-term experiment of organic management of mango (OMM) initiated in 2005 with a randomized block design with four replications. Two external areas, one with conventional mango cultivation (CMM) and the other a fragment of regenerating Caatinga vegetation (RCF), were used as reference areas. Soil samples were collected in the three management systems from the 0.00-0.05, 0.05-0.10, and 0.10-0.20 m layers, and the total organic carbon content and chemical fractions of organic matter were evaluated by determining the C contents of humin and humic and fulvic acids. Organic compost application significantly increased the contents of total C and C in humic substances in the experimental plots, mainly in the surface layer. However, compost 3 (50 % coconut bagasse, 40 % goat manure, 10 % castor bean residues) significantly increased the level of the non-humic fraction, probably due to the higher contents of recalcitrant material in the initial composition. The highest increases from application of the composts were in the humin, followed by the fulvic fraction. Compost application increased the proportion of higher molecular weight components, indicating higher stability of the organic matter.

Organic and nitrogen fertilization of soil under Syrah grapevine: effects on soil chemical properties and nitrate concentration.

Viticulture is an activity of great social and economic importance in the lower-middle region of the São Francisco River valley in northeastern Brazil. In this region, the fertility of soils under vineyards is generally poor. To assess the effects of organic and nitrogen fertilization on chemical properties and nitrate concentrations in an Argissolo Vermelho-Amarelo (Typic Plinthustalf), a field experiment was carried out in Petrolina, Pernambuco, on Syrah grapevines. Treatments consisted of two rates of organic fertilizer (0 and 30 m3 ha-1) and five N rates (0, 10, 20, 40, and 80 kg ha-1), in a randomized block design arranged in split plots, with five replications. The organic fertilizer levels represented the main plots and the N levels, the subplots. The source of N was urea and the source of organic fertilizer was goat manure. Irrigation was applied through a drip system and N by fertigation. At the end of the third growing season, soil chemical properties were determined and nitrate concentration in the soil solution (extracted by porous cups) was determined. Organic fertilization increased organic matter, pH, EC, P, K, Ca, Mg, Mn, sum of bases, base saturation, and CEC, but decreased exchangeable Cu concentration in the soil by complexation of Cu in the organic matter. Organic fertilization raised the nitrate concentration in the 0.20-0.40 m soil layer, making it leachable. Nitrate concentration in the soil increased as N rates increased, up to more than 300 mg kg-1 in soil and nearly 800 mg L-1 in the soil solution, becoming prone to leaching losses.

Nematóides em hortaliças formadoras de raízes e tubérculos: ocorrência, manejo e desafios.

2016

Reação de clones avançados de batata em campo naturalmente infestado pelo nematoide-das-galhas.

O objetivo desse trabalho foi avaliar a reação de clones avançados de batata do programa de melhoramento da Embrapa a Meloidogyne incognita em campo naturalmente infestado.

Hospedabilidade de plantas daninhas a Meloidogyne enterolobii.

O objetivo deste trabalho foi avaliar a hospedabilidade de dezesseis espécies de plantas daninhas, Acanthospermum australe, Ageratum conyzoides, Alternanthera tenella, Amaranthus hybridus, A. viridis, Bidens pilosa, Digitaria horizontalis, Eleusine indica, Euphorbia heerophylla, Hyptis sauaveolens, Ipomoea grandifolia, I. nil, Portulaca oleracea, Solanum americanum, Sida cordifolia e tagetes sp. ao nematoide-das-galhas, Meloidogyne enterolobil.

Determination of bioactive amines in tropical wines produced at Brazilian's Northeast.

The wine production in the region of the Sub-middle São Francisco river Valley has started there are few years ago.The region has a climate variability that allows to obtain two or three harvests per year, which influences significantly the composition of the grapes. This work aimed to evaluate the amount of amines present in white and red tropical wines produced in the Northeast of Brazil. The winemaking was done by the traditional method. After stabilizing the wines were bottled and then analyzed for the determination of the amines putrescine, spermidine and spermine, by thin layer chromatography (TLC). The harvests were in June (harvest I) and November (harvest II) 2009. The results showed that the edaphoclimatic conditions of the two harvests had significant influence (p> 0.05) on bioactive amines concentration, with high values for red wines. In addition, tropical wines from Sub-middle São Francisco river Valley showed adequate correlation between bioactive amines as compared to other wines in the world.