Feeding and oviposition preferences of Ctenarytaina spatulata Taylor (Hemiptera, Psyllidae) for Eucalyptus spp. and other Myrtaceae in Brazil

Feeding and oviposition preferences of Ctenarytaina spatulata Taylor (Hemiptera, Psyllidae) for Eucalyptus spp. and other Myrtaceae in Brazil. The Australian psyllid, Ctenarytaina spatulata Taylor (Hemiptera, Psyllidae), was first detected in Brazil in 1994, where it was found on drought-affected shoots of Eucalyptus grandis in a plantation located in the northern part of Paraná State. The oviposition and feeding preferences of this psyllid were examined on 19 Eucalyptus species, one Eucalyptus hybrid (Cambiju), three Corymbia species and four native Myrtaceae species (Hexaclames edulis, Marlieria edulis, Plinia trunciflora, and Psydium sp.) under greenhouse conditions. The largest populations of C. spatulata were found on E. robusta and E. pellita, while sizeable infestations were also found on E. urophylla, E. grandis, and the Cambiju hybrid. The plants with the greatest symptoms of damage were E. grandis and E. resinifera. Eucalyptus cinerea, E. benthamii, E. pilularis, and E. dunnii were not infested and E. cloeziana was minimally infested. Among the Corymbia species, the number of eggs of C. spatulata was very low on C. citriodora and C. torelliana. No eggs and nymphs of C. spatulata were found on native Brazilian Myrtaceae. The number of eggs on plants was highly correlated with the subsequent levels of nymphs, suggesting that egg counts can be used as a viable monitoring tool to assist with the integrated management of this pest.

Veliidae (Insecta, Heteroptera, Gerromorpha) from southeastern Brazil: three new species from Rio de Janeiro State, a new species group for Neotropical Rhagovelia Mayr, and notes on distribution and synonymy

Microvelia nelsoni sp. nov., M. takiyae sp. nov., and Rhagovelia mangaratiba sp. nov. are described. Rhagovelia scitula and R. whitei are transferred from the robusta group to the new whitei group. Rhagovelia denticulata is synonymized under R. scitula. Microvelia longipes, Oiovelia brasiliensis, Rhagovelia sooretama, R. trianguloides, R. vaniniae, and Stridulivelia quadrispinosa are recorded for the first time from Rio de Janeiro State. Additional new municipality records in Rio de Janeiro State are presented for Microvelia braziliensis, M. ioana, M. mimula, M. pulchella, Paravelia basalis, P. itatiayana, Rhagovelia accedens, R. agra, R. aiuruoca, R. elegans, R. hambletoni, R. henryi, R. itatiaiana, R. lucida, R. macta, R. modesta, R. novana, R. scitula, R. tenuipes, R. tijuca, R. triangula, and R. zela. Corrections are presented for the previously published distributions of Rhagovelia aiuruoca, R. lucida, R. macta, and R. triangula.

Chemical and physical properties of organic residues

Due to human activity, large amounts of organic residue are generated daily. Therefore, an adequate use in agricultural activities requires the characterization of the main properties. The chemical and physical characterization is important when planning the use and management of organic residue. In this study, chemical and physical properties of charcoal, coffee husk, pine-bark, cattle manure, chicken manure, coconut fiber, sewage sludge, peat, and vermiculite were determined. The following properties were analyzed: N-NH4+, N-N0(3)-, and total concentrations of N, P, S, K, Ca, Mg, Mn, Zn, Cu, and B, as well as pH, Electrical Conductivity (EC) and bulk density. Coffee husk, sewage sludge, chicken manure and cattle manure were generally richer in nutrients. The EC values of these residues were also the highest (0.08 - 40.6 dS m-1). Peat and sewage sludge had the highest bulky density. Sodium contents varied from 0 to 4.75 g kg-1, with the highest levels in chicken manure, cattle manure and sewage sludge. Great care must be taken when establishing proportions of organic residues in the production of substrates with coffee husk, cattle or chicken manure or sewage sludge in the calculation of the applied fertilizer quantity in crop fertilization programs.

Fertilization response likelihood for the interpretation of leaf analyses

Leaf analysis is the chemical evaluation of the nutritional status where the nutrient concentrations found in the tissue reflect the nutritional status of the plants. Thus, a correct interpretation of the results of leaf analysis is fundamental for an effective use of this tool. The purpose of this study was to propose and compare the method of Fertilization Response Likelihood (FRL) for interpretation of leaf analysis with that of the Diagnosis and Recommendation Integrated System (DRIS). The database consisted of 157 analyses of the N, P, K, Ca, Mg, S, Cu, Fe, Mn, Zn, and B concentrations in coffee leaves, which were divided into two groups: low yield (< 30 bags ha-1) and high yield (> 30 bags ha-1). The DRIS indices were calculated using the method proposed by Jones (1981). The fertilization response likelihood was computed based on the approximation of normal distribution. It was found that the Fertilization Response Likelihood (FRL) allowed an evaluation of the nutritional status of coffee trees, coinciding with the DRIS-based diagnoses in 84.96 % of the crops.

Phosphorus transformation in poultry litter and litter-treated Oxisol of Brazil assessed by 31P-NMR and wet chemical fractionation

Large quantities of poultry litter are being produced in Brazil, which contain appreciable amounts of phosphorus (P) that could be of environmental concern. To assess the immediate environmental threat, five poultry litters composed of diverse bedding material were incubated for 43 days under greenhouse conditions. The litters consisted of: coffee bean husk (CH); wood chips (WC); rice husk (RH); ground corn cobs (CC) and ground napier grass (NG) (Pennisetum purpureum Schum.), in which the change in forms of soluble P was evaluated using 31P NMR spectroscopy. On average, 80.2 and 19.8 % of the total P in the extract, respectively, accounted for the inorganic and organic forms before incubation and 48 % of the organic P was mineralized to inorganic P in 43 days of incubation. Wide variation in the organic P mineralization rate (from 82 % -WC to 4 % - NG) was observed among litters. Inorganic orthophosphate (99.9 %) and pyrophosphate (0.1 %) were the only inorganic P forms, whereas the organic P forms orthophosphate monoesters (76.3 %) and diester (23.7 %) were detected. Diester P compounds were mineralized almost completely in all litters, except in the CH litter, within the incubation period. Pyrophosphates contributed with less than 0.5% and remained unaltered during the incubation period. Wood-chip litter had a higher organic P (40 %) content and a higher diester: monoester ratio; it was therefore mineralized rapidly, within the first 15 days, achieving steady state by the 29th day. Distinct mineralization patterns were observed in the litter when incubated with a clayey Oxisol. The substantial decrease observed in the organic P fraction (Po) of the litter types followed the order: CH (45 %) > CC (25 %) > RH (13 %) ≈ NG (12 %) > WC (5 %), whereas the Pi fraction increased. Incubation of RH litter in soil slowed down the mineralization of organic P.

Soil quality indicators in a rhodic kandiudult under different uses in northern Parana, Brazil

Sustainable use of soil, maintaining or improving its quality, is one of the goals of diversification in farmlands. From this point of view, bioindicators associated with C, N and P cycling can be used in assessments of land-use effects on soil quality. The aim of this study was to investigate chemical, microbiological and biochemical properties of soil associated with C, N and P under different land uses in a farm property with diversified activity in northern Parana, Brazil. Seven areas under different land uses were assessed: fragment of native Atlantic Forest; growing of peach-palm (Bactrys gasipaes); sugarcane ratoon (Saccharum officinarum) recently harvested, under renewal; growing of coffee (Coffea arabica) intercropped with tree species; recent reforestation (1 year) with native tree species, previously under annual crops; annual crops under no-tillage, rye (Cecale cereale); secondary forest, regenerated after abandonment (for 20 years) of an avocado (Persea americana) orchard. The soil under coffee, recent reforestation and secondary forest showed higher concentrations of organic carbon, but microbial biomass and enzyme activities were higher in soils under native forest and secondary forest, which also showed the lowest metabolic coefficient, followed by the peach-palm area. The lowest content of water-dispersible clay was found in the soil under native forest, differing from soils under sugarcane and secondary forest. Soil cover and soil use affected total organic C contents and soil enzyme and microbial activities, such that more intensive agricultural uses had deeper impacts on the indicators assessed. Calculation of the mean soil quality index showed that the secondary forest was closest to the fragment of native forest, followed by the peach-palm area, coffee-growing area, annual crop area, the area of recent reforestation and the sugarcane ratoon area.

Soluble carbon in oxisol under the effect of organic residue rates

The application of organic residues to the soil can increase soluble organic carbon (SOC) and affect the pH and electrolytic conductivity (EC) of the soil. However, the magnitude of these changes depends on the type of residue and the applied dose. This study aimed to evaluate the effect of increasing C rates contained in organic residue on the pH, EC, water-extractable total carbon (WETC), water-extractable organic carbon (WEOC), and water-extractable inorganic carbon (WEIC) in soil treated with manure (chicken, swine, and quail), sawdust, coffee husk, and sewage sludge. The levels of total C (TC- KH2PO4), organic carbon (OC- KH2PO4), and inorganic C (IC- KH2PO4) extractable by a 0.1 mol L-1 KH2PO4 solution were also quantified in soil under the effect of increasing rates of chicken and quail manures. The following rates of organic residue C were applied to a dystrophic Red Latosol (Oxisol) sample: 0, 2,000, 5,000, 10,000, and 20,000 mg kg-1. The addition of organic residues to the soil increased pH, except in the case of sewage sludge, which acidified the soil. The acidity correction potential of chicken and quail manure was highest, dependent on the manure rate applied; regardless of the dose used, sawdust barely alters the soil pH. At all tested rates, the EC of the soil treated with swine manure, coffee husk, and sawdust remained below 2.0 dS m-1, which is a critical level for salinity-sensitive crops. However, the application of chicken or quail manure and sewage sludge at certain rates increased the EC to values above this threshold level. Highest levels of WETC, WEOC, and WEIC were obtained when chicken and quail manure and coffee husk were applied to the Oxisol. The quantities of SOC extracted by KH2PO4 were higher than the quantities extracted by water, demonstrating the ability of soil to adsorb C into its colloids.

Spatial estimation of foliar phosphorus in different species of the genus Coffea based on soil properties

Information underlying analyses of coffee fertilization systems should consider both the soil and the nutritional status of plants. This study investigated the spatial relationship between phosphorus (P) levels in coffee plant tissues and soil chemical and physical properties. The study was performed using two arabica and one canephora coffee variety. Sampling grids were established in the areas, and the points georeferenced. The assessed properties of the soil were levels of available phosphorus (P-Mehlich), remaining phosphorus (P-rem) and particle size, and of the plant tissue, phosphorus levels (foliar P). The data were subjected to descriptive statistical analysis, correlation analysis, cluster analysis, and probability tests. Geostatistical and trend analyses were only performed for pairs of variables with significant linear correlation. The spatial variability for foliar P content was high for the variety Catuai and medium for the other evaluated plants. Unlike P-Mehlich, the variability in P-rem of the soil indicated the nutritional status of this nutrient in the plant.

Aggregate stability by the "high energy moisture characteristic" method in an oxisol under differentiated management

Studies testing the High Energy Moisture Characteristic (HEMC) technique in tropical soils are still incipient. By this method, the effects of different management systems can be evaluated. This study investigated the aggregation state of an Oxisol under coffee with Brachiaria between crop rows and surface-applied gypsum rates using HEMC. Soil in an experimental area in the Upper São Francisco region, Minas Gerais, was studied at depths of 0.05 and 0.20 m in coffee rows. The treatments consisted of 0, 7, and 28 Mg ha-1 of agricultural gypsum rates distributed on the soil surface of the coffee rows, between which Brachiaria was grown and periodically cut, and compared with a treatment without Brachiaria between coffee rows and no gypsum application. To determine the aggregation state using the HEMC method, soil aggregates were placed in a Büchner funnel (500 mL) and wetted using a peristaltic pump with a volumetric syringe. The wetting was applied increasingly at two pre-set speeds: slow (2 mm h-1) and fast (100 mm h-1). Once saturated, the aggregates were exposed to a gradually increasing tension by the displacement of a water column (varying from 0 to 30 cm) to obtain the moisture retention curve [M = f (Ψ) ], underlying the calculation of the stability parameters: modal suction, volume of drainable pores (VDP), stability index (slow and fast), VDP ratio, and stability ratio. The HEMC method conferred sensitivity in quantifying the aggregate stability parameters, and independent of whether gypsum was used, the soil managed with Brachiaria between the coffee rows, with regular cuts discharged in the crop row direction, exhibited a decreased susceptibility to disaggregation.

SOIL QUALITY IN RELATION TO FOREST CONVERSION TO PERENNIAL OR ANNUAL CROPPING IN SOUTHERN BRAZIL

Many forested areas have been converted to intensive agricultural use to satisfy food, fiber, and forage production for a growing world population. There is great interest in evaluating forest conversion to cultivated land because this conversion adversely affects several soil properties. We examined soil microbial, physical, and chemical properties in an Oxisol (Latossolo Vermelho distrófico) of southern Brazil 24 years after forest conversion to a perennial crop with coffee or annual grain crops (maize and soybeans) in conventional tillage or no-tillage. One goal was to determine which soil quality parameters seemed most sensitive to change. A second goal was to test the hypothesis that no-tillage optimized preservation of soil quality indicators in annual cropping systems on converted land. Land use significantly affected microbial biomass and its activity, C and N mineralization, and aggregate stability by depth. Cultivated sites had lower microbial biomass and mineralizable C and N than a forest used as control. The forest and no-tillage sites had higher microbial biomass and mineralizable C and N than the conventional tillage site, and the metabolic quotient was 65 and 43 % lower, respectively. Multivariate analysis of soil microbial properties showed a clear separation among treatments, displaying a gradient from conventional tillage to forest. Although the soil at the coffee site was less disturbed and had a high organic C content, the microbial activity was low, probably due to greater soil acidity and Al toxicity. Under annual cropping, microbial activity in no-tillage was double that of the conventional tillage management. The greater microbial activity in forest and no-tillage sites may be attributed, at least partially, to lower soil disturbance. Reducing soil disturbance is important for soil C sequestration and microbial activity, although control of soil pH and Al toxicity are also essential to maintain the soil microbial activity high.

Seletividade alimentar e influência da idade da folha de Eucalyptus SPP. para Thyrinteina Arnobia (Lepidoptera: Geometridae)

Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae) é considerada uma das mais sérias pragas do eucalipto no Brasil. Este trabalho foi realizado com o objetivo de estudar a preferência alimentar de T. arnobia em seis espécies de eucalipto e a influência da idade foliar sobre a seleção hospedeira, utilizando-se folhas jovens e velhas de Eucalyptus grandis, Eucalyptus camaldulensis, Eucalyptus saligna, Eucalyptus citriodora, Eucalyptus robusta e Eucalyptus cloeziana. Lagartas de T. arnobia alimentadas na geração anterior com folhas de E. grandis preferiram folhas jovens de E. grandis e E.cloeziana, enquanto as alimentadas com E. saligna, na geração anterior, preferiram folhas velhas de E. grandis. A espécie preferida por lagartas de T. arnobia foi E. grandis, observando-se, também maior preferência por folhas jovens que por folhas velhas nas espécies utilizadas nos testes.

Variação no teor de lipídios em grãos de variedades de Coffea canephora

O objetivo deste trabalho foi estudar a variação do teor de lipídios em grãos de diferentes variedades de Coffea canephora Pierre, do Banco de Germoplasma de Café, do Instituto Agronômico, Campinas, SP, Brasil. Foram analisadas sementes de 47 plantas pertencentes às variedades Robusta (3), Kouilou ou Conilon 66 (13), Apoatã (12), Guarini (8), Laurentii (7) e Bukobensis (4). A quantidade de matéria graxa foi determinada após extração com éter de petróleo. Os resultados revelaram diferença entre o teor médio de lipídios das variedades Kouilou (7,33%) e Robusta (10,91%). Foram constatadas diferenças também dentro das plantas das seis variedades, com amplitudes de 15,57% a 21,63% em Apoatã e Laurentii, respectivamente.

Índices de seleção no aprimoramento simultâneo dos componentes da produção de frutos em açaizeiro

O objetivo deste trabalho foi determinar a estratégia seletiva mais adequada para o incremento simultâneo de componentes da produção de frutos em açaizeiro (Euterpe oleracea). Implantou-se um experimento com 25 progênies de meio-irmãos, no Município de Santa Izabel, PA, tendo-se utilizado o delineamento de blocos ao acaso, com quatro repetições e parcela de cinco plantas. Os índices de seleção de Smith & Hazel, Williams, e Mulamba & Mock foram aplicados em três estratégias seletivas. Foram utilizados, como pesos econômicos, os coeficientes de variação genéticos, a herdabilidade, a razão entre a correlação genética do caráter selecionado com a produção de frutos, e a somatória de todos os caracteres que compõem o índice e a produção de frutos. Aponderação pela razão das correlações permitiu que os índices de seleção discriminassem as melhores progênies nas diferentes estratégias de seleção avaliadas. A seleção simultânea por meio do índice de Mulamba & Mock, quanto ao número de meses em frutificação, ao número de cachos colhidos, à produção de frutos e ao número de ráquilas no cacho, estima ganhos de forma mais robusta.

Caracterização morfológica da semente e da plântula de bacurizinho (Rheedia acuminata (Ruiz et Pav.) Plachon et Triana - Clusiaceae)

O bacurizinho é uma espécie frutífera do gênero Rheedia, nativa da Amazônia, e raramente cultivada, pois seus frutos, embora comestíveis, apresentam polpa escassa. Os estudos com o bacurizinho visam a sua utilização como porta-enxerto, redutor de porte para outras espécies do gênero Rheedia e Garcinia que apresentam altura elevada, como o bacuripari (Rheedia macrophylla Planchon et Triana- Clusiaceae) e o mangostão (Garcinia mangostana L.). Este trabalho teve como objetivo caracterizar, morfologicamente, a semente e a plântula dessa espécie. A semente é exalbuminosa, bitegumentada, com a testa de coloração marrom, apresentando vários feixes vasculares bem visíveis, distinguindo-se por sua coloração um pouco mais clara. O hilo é arredondado, de coloração escura, com pequena região mais clara ao centro, correspondendo no ponto de entrada de feixe vascular. A micrópila situa-se próxima ao hilo, sobre uma pequena protuberância triangular. O embrião é anômalo, hipocotilar e é representado unicamente por um longo eixo hipocótilo-radícula, sendo os cotilédones diminutos, aparecendo apenas na extremidade superior no lado oposto da micrópila. Durante a germinação, ocorre primeiramente a emergência de delgada raiz primária, no pólo oposto onde será originado o epicótilo. Essa raiz cresce aproximadamente 5-7cm e cessa, fenecendo posteriormente. Por ocasião da emergência do epicótilo, ocorre ao mesmo tempo a formação de uma raiz adventícia, na base do epicótilo, bem mais robusta que a anterior e que se constituirá no sistema radicular da planta. Precedendo a abertura do primeiro par de metáfilos, desenvolvem-se no epicótilo três pares de catafilos opostos e de coloração esverdeada. A germinação é hipógea e a plântula do tipo criptocotiledonar.

Suscetibilidade de cercas-vivas, quebra-ventos e plantas invasoras ao vírus da leprose e sua transmissão para laranjeiras por Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae)

Objetivou-se avaliar a potencialidade de algumas plantas freqüentes em pomares cítricos de hospedar o vírus da leprose, transmitido por Brevipalpus phoenicis (Geijskes). Foram utilizadas as seguintes plantas: Hibiscus sp. L., Malvaviscus mollis DC., Grevillea robusta A. Cunn., Mimosa caesalpiniaefolia Benth., Bixa orellana L., Commelina benghalensis L., Bidens pilosa L., Sida cordifolia L. e Ageratum conyzoides L.. Duas criações-estoque do ácaro foram realizadas, sendo uma sobre frutos com sintomas de leprose e outra sobre frutos sem sintomas. De cada planta hospedeira do ácaro, escolheram-se duas folhas, delimitando-se na face inferior de cada planta uma área, que recebeu ácaros criados sobre frutos com lesões de leprose, que aí permaneceram durante sete dias. Os ácaros foram em seguida transferidos para mudas cítricas das variedades Natal e Valência e mantidos em casa de vegetação. As folhas das diferentes espécies vegetais sobre as quais os ácaros estavam anteriormente, foram destacadas e conservadas em placas de Petri, sobre algodão e papel-filtro umedecido. Ácaros criados sobre frutos sem lesões de leprose foram mantidos por três dias sobre essas folhas e, posteriormente, transferidos para novas mudas cítricas, que também foram subseqüentemente mantidas em uma casa de vegetação. Após 60 dias, quantificou-se o número de lesões de leprose nas mudas cítricas. Os resultados evidenciaram que o ácaro não perdeu a capacidade de transmissão do vírus para mudas cítricas após acesso alimentar por sete dias sobre qualquer uma das plantas intermediárias consideradas no estudo. Ácaros provenientes de frutos sem lesões de leprose adquiriram o vírus da leprose e o transmitiram a mudas cítricas quando tiveram acesso alimentar a C. benghalensis, A. conyzoides, B. pilosa, S. cordifolia e B. orellana, onde, anteriormente, ácaros criados sobre frutos com lesões de leprose permaneceram por sete dias. Estes resultados evidenciam a potencialidade de estas plantas serem depositárias e fonte de transmissão do vírus para plantas cítricas suscetíveis.