Relationships among Pratylenchus jaehni and P. coffeae populations from Brazil.

Wilcken, S.R.S., E.S. Mori, M. Bacci, L.C.C.B. Ferraz, C.M.G. Oliveira & M.M. Inomoto. 2008. Relationships among Pratylenchus jaehni and P. coffeae populations from Brazil. The relationships among Pratylenchus jaehni (C) and six amphimitic Pratylenchus populations from Brazil (three from banana, PcB1, PcB2, and PcB3; one from Aglaonema sp., M2; one from coffee, K5; and one from citrus, C) were studied through morphological and molecular analysis, and pathogenicity test. The analysis of morphometric characteristics of PcB1, M2, C2 and K5, compared with P. jaehni and P. coffeae (K6) data obtained from literature, delineated three groups: P. coffeae (K6), PcB1 and M2; P. jaehni (C1) and C2; and K5. RAPD analysis of PcB1, PcB2, PcB3, M2, C2, K5 and P.jaehni (C1) demonstrated that these populations form three distinct genetic groups: PcB1, PcB2, PcB3 and M2; P.jaehni and C2; and K5. In pathogenicity test, K5 reproduced well on coffee and caused extensive root necrosis, but C2 did not. Population C2 reproduced well on Rangpur lime, which was previously rated as poor host to K5. Therefore, the results demonstrated that C2 is P. jaehni, K5 is an undescribed species of Pratylenchus, and PcB1, PcB2 and PcB3 are P. coffeae. The taxonomic status of M2 remains inconclusive.

Fungus incidence on peanut grains as affected by drying method and Ca nutrition

An experiment was conducted to study the effects of liming and drying method on Ca nutrition, fungus infection and aflatoxin production potential on peanut (Arachis hypogea) grains. Peanut cv. Botutatu was grown in the absence or presence of liming to raise the base saturation of the soil from 20 to 56%. Calcium contents of the soil were increased from 5.5 to 14.6 mmol((c))kg-1 and pH from 4.2 to 4.9. After harvest, plants and pods were dried in (1) shade, (2) field down to 100 g water kg-1 (3) field down to 250 g water kg-1 and transferred to a forced-air oven at 30°C, (4) field down to 360 g water kg-1 and transferred to a forced-air oven at 30°C. Calcium contents were analyzed in the grains, pericarps and seed coats. The incidence of Aspergillus spp., Penicillium spp., Rhizopus spp. and potential aflatoxin production in vitro were evaluated, as well as the seed coat thickness. The seed coat was thicker when peanut was grown in the presence of lime, leading to a decrease in seed infection by Aspergillus spp. and Penicillium spp. When plants were dried in shade, the growth of aflatoxinogenic fungi was independent of liming. However, in plants dried in the field or field + oven, the development of these fungi was decreased and even suppressed when the Ca content of the seed coat was increased from 2.2 to 5.5 g kg-1.

Efeito da época de colheita e da calagem no rendimento de sementes comercializáveis de amendoim cv. Botutatu

A field experiment was carried out to study the effects of liming and time of harvesting on peanut cv. Botutatu (Arachis hypogaea L.) seed yield and yield components in the period of July, 1991 to February, 1992, in São Manuel, State of São Paulo. The soil was a Dark Red Latosol (Hapludult, sandy loam), and the experimental design was a subplot replicated four times in completely randomized blocks. Lime levels (0.0 and 1.75 t/ha) were applied in the plots, and the subplots were nine weekly harvests, starting at 87 days after planting (DAP). There was no effect of lime on hulls or seed yield and on peanut yield components. The germination of seeds in hulls was incresead at each harvest and was lower at lime presence. The highest yield was observed at 129 DAP.

Uso de resíduos agroindustriais nas produções de cana-de-açúcar, açúcar e álcool

In order to study the effect of gypsum, lime and the mixture of lime-gypsum, associated with syrup in the agricultural and industrial production and in the rooting of sugar-cane (Saccharum spp.), var. IAC 58-480, one experiment was carried out in soil Terra Roxa Estrutura. Sugar-cane was planted in November 1986, and the cane-plant harvesting in September 1988. Three successive harvests were collected.The experiment was set in a randomized block design with seven treatments and four replications .The treatments were: T1 - 1.2 ton/ha of lime; T2 - 0.8 ton/ha of lime + 0.4 ton/ha of gypsum; T3 - 0.6 ton/ha of lime + 0.6 ton/ha of gypsum; T4 - 0.4 ton/ha of lime + 0.8 ton/ha of gypsum; T5 - 1.2 ton/ha of gypsum; T6 - 2.4 ton/ha of gypsum; T7 - control. Syrup was applied at the amount of 45 m3/ha.In September 1990, after the third harvesting, the second application of the treatments was made, the gypsum being applied in amounts four times greater than those of that put into practice at the planting. During harvest, the following parameters were evaluated: number, length and average diameter of the stalks; yield; and probable sugar and theoretical alcohol production per hectare.The results showed that the second application of the treatments recuperated the crop. Greater yields were achieved when the gypsum was associated with lime or syrup.

The significance of root growth on cotton nutrition in an acidic low-P soil

Toxic levels of Al and low availability of Ca have been shown to decrease root growth, which can also be affected by P availability. In the current experiment, initial plant growth and nutrition of cotton (Gossypium hirsutum var. Latifolia) were studied as related to its root growth in response to phosphorus and lime application. The experiment was conducted in Botucatu, Sao Paulo, Brazil, in pots containing a Dark Red Latosol (Acrortox, 20% clay, 72% sand). Lime was applied at 0.56, 1.12 and 1.68 g kg -1 and phosphorus was applied at 50, 100 and 150 mg kg -1. Two cotton (cv. IAC 22) plants were grown per pot for up to 42 days after plant emergence. There was no effect of liming on shoot dry weight, root dry matter yield, root surface and length, but root diameter was decreased with the increase in soil Ca. Shoot dry weight, as well as root length, surface and dry weight were increased with soil P levels up to 83 mg kg -1. Phosphorus concentration in the shoots was increased from 1.6 to 3.0 g kg -1 when soil P was increased from 14 to 34 mg kg -1. No further increases in P concentration were observed with higher P rates. The shoot/root ratio was also increased with P application as well as the amount of nutrients absorbed per unit of root surface. In low soil P soils the transport of the nutrient to the cotton root surface limits P uptake. In this case an increase in root growth rate due to P fertilisation does not compensate for the low P diffusion in the soil.

Key features of alumina/magnesia/graphite refractories for steel ladle lining

The corrosion resistance of resin bonded alumina/magnesia/graphite refractories containing different kinds of aggregates were investigated when submitted to the action of slags of several CaO/SiO2 ratios. The laboratory testing was performed by means of the rotary slag attack test. Specifically evaluated was the influence of alumina/carbon ratio and magnesia and silica contents on the refractories corrosion resistance. It was found that this property could be improved by increasing the refractory Al2O3/SiO2 ratio as well as by choosing the appropriate Al2O3/C ratio. © 2000 Elsevier Science Ltd.

Susceptibility of tangerines to citrus variegated chlorosis

Citrus variegated chlorosis (CVC), a citrus disease first discovered in Brazil in 1987, is caused by the bacterium Xylella fastidiosa and transmitted by sharpshooters and budwood. Since the disease affects almost all sweet orange cultivars, it has become one of the most serious problems for Brazilian citriculture. To evaluate their resistance to CVC disease, fifteen tangerines or mandarins (C. reticulata Blanco) and their hybrids were grafted on Rangpur lime (C. limonia Osb.) and inoculated with CVC-contaminated Pera sweet orange (C. sinensis (L.) Osb.) by twig grafting in a greenhouse. Tangerines and their hybrids Wilking, Fortune, Sunki, Ellendale, Orlando tangelo, Nunes clementine, Nova, Sun Shu Sha Kat, Suenkat, and Batangas showed CVC leaf symptoms and gave positive results on enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) (with specific primers for X. fastidiosa), indicating that they are susceptible to CVC. Although X. fastidiosa bacteria were detected by ELISA and PCR in inoculated plants of tangerines Cravo and Oneco, no CVC leaf symptoms were observed on these two cultivars, suggesting that they are tolerant to the disease. CVC leaf symptoms were not observed and X. fastidiosa was not detected in tangerine Dancy and mandarins Okitsu satsuma and Ponkan after inoculation, showing that they are resistant to the disease.

Recuperação de povoamento de Eucalyptus urophylla com aplicações de nitrogênio, potássio e calcário dolomítico

A plantation of Eucalyptus urophylla, established in 1984 on a Quartzpsamment Soil, at Altinopolis, São Paulo State, presented in 1989 an medium increment of the cylindrical volume of the trees of 13.97 m 3/ha/year and also showed deficiency symptoms of potassium, calcium and magnesium. At 4.33 years after planting were applied two doses of nitrogen (0 and 10 g/tree of N), potassium (0 and 20 g/tree of K 2O) and of dolomitic lime (0 and 500 g/tree), combined in a randomized block design arranged in a factorial way (2 × 2 × 2), with four replications, in order to study the recuperation of the tree growth rate. Evaluations of the trees growth were performed at 4.33, 5.67, 6.75 and at 7.58 years when cutting the plantation was done. The soil fertility and leaf concentrations of N, K, Ca and Mg were analyzed before and after the application of the treatments. The accumulation and distribution of biomass and of these nutrients in the tree components and in the litter, and the economic studies referring to the volumes of wood were also evaluated 7.58 years after planting. Potassium fertilization increased the mass of potassium in stemwood, stembark, foliage, fruits and litter, but the increase was greater in foliage and in the stembark. Liming increased the mass of magnesium in stemwood, stembark, foliage and litter, but the increase was greater in the litter. There was no isolated effect of nitrogen fertilization. The growth rate of trees was recovered with the potassium application, which increased the mean annual increment (MAI) of cylindrical volume from 13.85 m 3/ha/year without fertilizer to 16.82 m 3/ha/year. At 7.58 years after planting, there was observed an effect of the N x K x dolomitic lime interaction in the wood production. In the absence of nitrogen and dolomitic lime, the application of potassium increased the real volume of 43% and there was a gain of US$ 86.79/ha.

Extra̧ão de Macro e Micronutrientes Pela Parte Aérea de Erva-Doce EM Fuņão de Calagem e Aduba̧ão com Esterco de Cama de Frango

A greenhouse experiment was conducted in the Soil Science Department of the Botucatu College of Agricultural Sciences (UNESP), Brazil, using a Dark Red Latosol in 25 L pots. The soil was limed to 50 and 70% of base saturation; and doses 0, 10, 20, 30 and 40 t ha-1 of chicken manure were applied, in December of 1999. The experimental design was completely randomized blocks with a factorial arrangement 5x2, 10 treatments and three replications. This work was carried to evaluate leaf number, height plants, fresh and dry weight by aerial part of sweet fennel, and macronutrients and micronutrients removal. The organic fertilization affected the accumulation of N, P, K, S, B and Mn; liming affected the nutrient uptake, except for the Ca, Mg, S and Fe; the interaction of factors affected K, Mg and Mn.

Atributos químicos do solo e produtividade do milho afetados por corretivos e manejo do solo

A field experiment was carried out in the Lageado Experimental Farm belonging to the São Paulo State University - UNESP, Campus of Botucatu, SP, in a distrophic Nitosoil in 1997/98. The objective was to compare the effects of magnesium termophosphate; termophosphate + lime; termophosphate + phosphogypsum + sugarcane vinnace application on the chemical characteristics of the soil and on the corn (Zea mays L.) yield cultivated in no-tillage and conventional tillage systems. The Crotalaria juncea was cultivated as mulch-producing to make possible the establishment of the tillage systems. The mean modifications in the soil fertility were due to aplication of the magnesium termophosphate. The differences between the two tillage systems, related to crop productivity, were associated to the smaller N content in the corn leaf in the no-tillage system.

Efeito da calagem e sulfato de amônio no algodão. I - Transporte de cátions e ânions no solo

Applying lime on the soil surface in soils managed under no-tillage has caused an excess of basic cations in the most superficial layers of the soil profile. On the other hand, subsoil acidity is considered a constraint to the development of deep plant roots. The objective of this study was to evaluate Ca 2+, Mg 2+, NO 3- and SO 4 2- leaching in the soil profile as affected by liming and top dressing nitrogen fertilization in cotton, grown with straw cover on the soil surface. Cotton plants (Gossypium hirsutum) were grown for 60 days in PVC columns filled with a Distroferric Red Latosol (sand loam Rhodic Oxisol) with liming applied over the straw on the soil surface, incorporated liming 0-20 cm deep, or without liming. Nitrogen was applied at rates of 0, 50, 100 and 150 kg ha -1 as ammonium sulfate. The PVC columns were set up in layers of 0-5, 5-10, 10-20, 20-30 and 30-30 cm, totaling 15.71 dm 3. The ammonium sulfate application caused intense leaching of SO 4 2- in the soil, irrespective of the lime application method. Liming increased the concentration of NO 3 in the 0-20 cm soil layer, whereas the correction of the soil acidity did not affect the NO 3- concentration in the 30-50 cm soil layer. The influence of ammonium sulfate on Ca 2+ leaching below 20 cm was only observed in the soil with incorporated lime. Nitrogen application resulted in extensive Mg 2+ leaching from the soil, regardless of the lime application method. In the soil layer below 30 cm, SO 4 2- presented a higher correlation than NO 3- in the formation of ionic pairs with Ca 2+ and Mg 2+.

Efeito de resíduos vegetais de milheto (Pennisetum americanum) e da calagem em algumas propriedades físicas e químicas de um nitossolo vermelho em sistema de semeadura direta

This work studied alterations of physical properties of a distroferric red nitosol due to millet (Pennisetum americanum) covering, with or without liming, in a no-tillage system during the agricultural years of 1999/2000 and 2000/2001, using soybean and corn as culture succession. 6m×10m plots, with and without millet as vegetal covering, received only one initial superficial application of limestone, 3.1 t ha-1 in the first half of each plot in order to obtain 70% base saturation (V), after the desiccation of the millet. Some physical properties as soil density, aggregate stability, > 2 mm aggregate proportion, macro and micro porosity were analyzed whereas the chemical analysis determined Ca and Mg macro nutrients, organic matter, soil pH and H+Al. Millet vegetal residues and surface liming did not alter soil density nor the average weight diameter (AWD), > 2 mm aggregate, soil macro porosity and organic matter content, twenty-four months after the no-tillage system implantation for studied experimental conditions. Soil micro porosity was significantly affected in layers deeper than 0.20 m, in treatment with millet and limestone. Calcium, magnesium and H + Al contents and the soil pH values suffered significant alterations in superficial layer, between 0-0.05 m.

Agronomic effectiveness of cationic phosphate impurities present in superphosphate fertilizers as affected by soil pH

The general concept that low-water-soluble phosphorus (P) fertilizers should be more agronomically effective when applied to acidic soils was developed based on sources containing mainly calcium (Ca)-P compounds, but it may not hold true for sources with different chemical composition. To obtain information related to this issue, two important iron (Fe)-potassium (K)-P compounds present in superphosphates [Fe 3 KH 8 (PO 4 ) 6·6H 2 O, H8, and Fe 3 KH 14 (PO 4 ) 8·4H 2 O, H14] were prepared and characterized. These P sources were used to provide 30 and 60 mg P kg -1 as neutral ammonium citrate (NAC)+H 2 O-soluble P. Reagent-grade monocalcium phosphate (MCP) was used as a standard P source with high water solubility with an additional rate of 120 mg P kg -1 included. Also, mixtures of both Fe-K-P compounds and MCP were prepared to provide 0, 25, 50, 75, and 100% of the total P as MCP. All sources were applied to a clayey loamy acid soil (pH 5.3) classified as Rhodic Kanhapludult. The soil was incubated at two rates (0 and 10 g kg -1 ) of lime, which resulted in pH 5.4 and 6.8. Upland rice was cultivated to maturity. The H14 compound confirmed to be a highly effective source of P for the rice plants at both soil pH, as opposed to the H8, which was poorly effective when applied alone. When mixed with water-soluble P (WSP), the H8 was able to provide P to the plants with the maximum yield of upland rice reached with 54.8 and 80.5% of WSP for pH 5.4 and 6.8, respectively. The high agronomic performance of the H14 compound clearly indicates that this low-water-soluble P source cannot be deemed as ineffective at high soil pH. Copyright © Taylor & Francis Group, LLC.

Comportamento contrátil de barreiras selantes de solo estabilizado para base de lagoas de tratamento

Liners were proposed as subsoil contamination protection devices for waste disposal sites. In the rural environment, they can be used to construct pond bottoms for liquid waste treatment, but the construction needs to be quick and cheap. A good technical solution for these situations is the use of local soil compacted with low quantities of cement or lime, obtaining good properties for this purpose. These barriers need special care about their contraction behavior which may compromise its use. This work shows the results of contraction tests in sandy soil specimens and others stabilized with lime and with cement. Soil structure changes during cure time were checked using electronic scan microscopy. Results show maximum soil contraction of 0.648% for specimen with 14 days cure process. After twenty eight days of cure the contraction values were lower than 0.5%, which classifies the material as of low contraction. Electronic scan image shows significant material structure alteration up to seven days cure. Results show that studied mixtures had appropriate contraction behavior for liner usage.

Biocompatibility of resin-based dental materials applied as liners in deep cavities prepared in human teeth

Background: Since only a few data have been published concerning the effects of resinous dental materials on the pulp-dentin complex, the aim of this study was to evaluate the biocompatibility of resin-based materials applied as liners in deep cavities prepared in duman teeth. Methods: After preparing class V cavities, the following dental materials were applied on the axial walls: group 1, Vitrebond™ (VIT; 3M ESPE); group 2, Ultra-Blend® Plus™ (UBP; Untradent); and group 3, Clearfil™ SE Bond (CSEB; Kuraray). In group 4 (control), the hard-setting calcium hydroxide cement Dycal (CH; Caulk/Dentsply) was used. The teeth extracted at 7 days or between 30 and 85 days after the clinical procedures were processed for histological evaluation. Results: For all the experimental and control groups, most of specimens exhibited no pulpal response or slight inflammatory reaction associated with slight tissue disorganization at 7-day period. Moderate inflammatory pulpal response occurred only in one tooth (RDT = 262 μm) of group 3 in which transdentinal diffusion of resin components was observed. Conclusion: The resin-based dental cements VIT and UBP as well as the bonding agent CSEB presented acceptable biocompatibility when applied in deep cavities prepared in sound human teeth. © 2006 Wiley Periodicals, Inc.