Resumen La fumagina (Capnodium sp.) es una enfermedad que se presenta en los cítricos y limita el desarrollo de las plantas, al reducir la actividad fotosintética y el intercambio gaseoso. Se evaluó el efecto de cuatro tratamientos CALSU10 en el control de la fumagina en hojas de mandarina (Citrus reticulata): caldo sulfocálcico al 10 %, Podas: podas de mantenimiento, CALSU10 + Podas: caldo sulfocálcico al 10 %> y podas de mantenimiento, Testigo: sin aplicación de caldo sul-focálcico, ni poda. Los resultados obtenidos mostraron que la incidencia de fumagina fue similar en todos los tratamientos a los 14, 28 y 42 días posteriores a la aplicación de tratamientos, y a los 56 días fue mayor en el Testigo y menor para CALSU10 + Podas. Este mismo tratamiento presentó diferencias significativas (p<0,05) con respecto a los demás tratamientos a los 56 días, para la escala de daño muy severo y hojas sanas. Finalmente se concluye que, en mandarina, la severidad y la incidencia de fumagina se puede reducir en un 28 y 42 % respectivamente, cuando se practican cuatro aplicaciones de sulfocálcico al 10 % junto con poda de saneamiento en el estadio fenológico de reposo vegetativo del árbol.

Abstract Fumagina (Capnodium sp.) is a disease that occurs in citrus and limits plant development by reducing photosynthetic activity and gas exchange. The effect of four treatments CALSU10: 10 %> sulfocalcic broth, Pruning: maintenance pruning, CALSU10 + Pruning: 10 % sulfocalcic broth and maintenance pruning, and Control: no application of sulfocalcic broth or pruning, on the control of fumagina on mandarin leaves (Citrus reticulata) was evaluated. The results obtained showed that the incidence of fuma-gina was similar in all treatments at 14, 28 and 42 days after the application of treatments, and at 56 days it was higher in the Control and lower for CALSU10 + Pruning. This same treatment showed significant differences (p<0.05) with respect to the other treatments at 56 days, for the scale of very severe damage and healthy leaves. Finally, it is concluded that, in mandarin, the severity and incidence of fumagina can be reduced by 28 and 42 %, respectively, when four applications of 10 %> sulfocalcic are made together with pruning at the phenological stage of vegetative rest of the tree.

Resumen El presente documento muestra el uso de métodos geoestadísticos para obtener mapas de incidencia de escama verde [Coccus viridis (Green); Hompoptera: Coccidae], una de las principales plagas del café (Coffea arabica); este insecto, además de causar daño directo, produce el medio para el desarrollo del hongo Capnodium sp., causante de la fumagina. Se seleccionaron cuatro parcelas de café con variedades Typica y Caturra; se georreferenciaron plantas al azar con muestreos quincenales. El objetivo del presente estudio fue analizar la distribución espacial de la escama verde y fumagina en el cultivo del café. Se detectó la presencia de focos de infestación e infección de escama verde y fumagina dentro de las parcelas y la correlación entre el insecto y el hongo causante de la enfermedad. Se obtuvieron semivariogramas teóricos ajustados a modelos Gaussiano, esférico y exponencial, con una distribución de tipo agregado en varios centros. La estimación de la superficie infestada e infectada por escama verde y fumagina se obtuvo a través del krigeado ordinario, y fue posible visualizar los meses de abril y mayo como los de mayor incidencia para escama verde y abril para fumagina, lo que coincide con los meses más importantes para la floración del café en la zona de estudio. Se encontró mediante análisis de correlación lineal simple para promedios aritméticos y coeficiente de correlación de Pearson que a mayor presencia de escama verde existe mayor concentración de fumagina.

Summary This document shows the use of geostatistical methods for constructing maps of incidence of green scale [Coccus viridis (Green); Hompoptera: Coccidae], one of the main pests of coffee (Coffea arabica); this insect, in addition to causing direct damage, produces the medium for the development of the fungus Capnodium sp. causing sooty mould. Four coffee plots were selected with varieties Typica and Caturra georeferencing plants randomly with samplings every two weeks. The objective of this study was to analyze the spatial distribution of green scale and sooty mould in coffee plantations, The presence of outbreaks of infestation and infection of green scale and sooty mould within the plots as well as the correlation between the insect and the fungus causing the disease were detected. Theoretical semivariograms adjusted to Gaussian, spherical and exponential models were obtained, with an aggregate-type distribution in several centers. The estimation of the area infested and infected by green scale and sooty mould was obtained through ordinary kriging, and it was possible to visualize the months April and May as those with the highest incidence for green scale and April for sooty mould, which coincides with the most important months for coffee flowering in the studied area. It was found by simple linear correlation analysis for arithmetic averages and Pearson correlation coefficient that the greater the presence of green scales, the higher the sooty mould concentration.

Las moscas blancas (Hemiptera: Aleyrodidae) son importantes plagas que afectan al género Citrus. En este trabajo se identificaron las especies presentes en naranjos de San Pedro (provincia de Buenos Aires) y se analizó su evolución poblacional y la de sus enemigos naturales bajo dos manejos sanitarios (convencional y orgánico). Mensualmente se registró la densidad de adultos y ninfas, la especie y densidad de parasitoides y predadores, la presencia de fumagina en hojas/frutos, el rendimiento y los agroquímicos aplicados. Las principales especies fueron Dialeurodes citri(Ashmead) y Singhiella citrifolii(Morgan), cuyas poblaciones de adultos predominaron entre octubre y mayo, sin diferencias entre los tipos de manejo. Las ninfas estuvieron presentes a lo largo del año, con mayores cantidades en los cultivos orgánicos. Los niveles de fumagina fueron similares para ambos manejos. El predador Euseius concordis (Chant) (Acari: Phytoseiidae) fue el enemigo natural más abundante, con mayor densidad en los cultivos orgánicos. Hubo bajos niveles de parasitismo por Encarsia protransvena Viggiani, Encarsia grupo strenua (Hymenoptera: Aphelinidae) y Neopomphale sp. (Hymenoptera: Eulophidae). El rendimiento de frutos fue mayor en el tratamiento convencional. Los resultados muestran la necesidad de controlar la plaga con productos menos nocivos para la fauna benéfica.

Whiteflies (Hemiptera: Aleyrodidae) are important pests that affect the genus Citrus. The objective of this study was to identify the species present in orange orchards in San Pedro (province of Buenos Aires) and to analyze their population evolution and that of their natural enemies under two sanitary management (conventional and organic). The density of adults, parasitized and non-parasitized nymphs, species and density of predators and parasitoids, presence of sooty mold on leaf/fruit, fruit yield and applied agrochemicals were recorded monthly. The prevalent species of whiteflies were Dialeurodes citri (Ashmead) and Singhiella citrifolii (Morgan), whose adult populations developed between October and May without differences between types of management. The nymphs were present throughout the year, with higher density in organic crops. Sooty mold levéis were similar for both managements. The predator Euseius concordis (Chant) (Acari: Phytoseüdae) was the most abundant natural enemy, with higher density in organic crops compared to conventional ones. There were low levéis of parasitism by Encarsia protransvena Viggiani, Encarsia group strenua (Hymenoptera: Aphelinidae) and Neopomphale sp. (Hymenoptera: Eulophidae). The fruit yield was higher in the conventional treatment. Results show the need of controlling the pest with less harmful producís for the beneficial fauna.

An investigation was carried out between August and November 2015 in order to understand the behavior of the lemon crop (Citrus aurantifolia Swingle) in "farm types" in the Province of Santa Elena, Ecuador. A "farm type" represents a group of farms with similar socio-economic characteristics. Four eightyears old "farms types" were selected. In each farm, 50plants were marked in which assessments were made. The trial did not have an experimental design but statistical analysis was done like a Completely Randomized Design (CRD), considering each farm type as a treatment and each plant as a replicate. The highest aphid (Aphis spp.) incidence was found in type I farms. Values were statistically different from type IV farms but similar to farm types II and III. The highest incidence of whitefly (Aleurothrixus floccosus), was found in type I farms that were statistically different from farm types III and IV. The highest incidence of sooty mold (Capnodium sp.), was found in type I farm that were statistically similar to other farms. The largest diameter and fruit weight, was found in farm type III with values that were statistically higher than farm types I and II but similar to farm type IV.

Se realizó una investigación entre agosto y noviembre del 2015, con el objetivo de conocer el comportamiento del cultivo de limón (Citrus aurantifolia Swingle) en "fincas tipo" de la provincia de Santa Elena, Ecuador. Una "finca tipo" es representativa de un grupo de fincas con características socioeconómicas similares. Se seleccionaron cuatro "fincas tipos" con cultivo de limón de ocho años de edad. En cada finca se marcaron 50 plantas, en las que se hicieron las evaluaciones. El ensayo no tuvo un diseño experimental, pero el análisis estadístico se hizo como si fuera un Diseño Completamente al Azar (DBCA), considerando cada finca como un tratamiento y cada planta como una repetición. Se encontró que la mayor incidencia de pulgones (Aphis spp.) correspondió a la finca tipo I, estadísticamente diferente a la finca IV pero similar a las fincas II y III. La mayor incidencia de mosca blanca (Aleurothrixusfloccosus), correspondió a la finca tipo I, estadísticamente diferente a las fincas III y IV. La mayor incidencia de fumagina (Capnodium sp.), correspondió a la finca tipo I, pero estadísticamente similar a las otras fincas. El mayor diámetro y peso del fruto, correspondió a la finca III, estadísticamente mayor a las fincas I y II pero similar a la finca IV.

In La Araucanía, the filbert aphid Myzocallis coryli (Goeze) is a pest that can cause various types of damage to hazelnut (Corylus avellana L.) including reduction in nut size and nut emptiness. M. coryli can also leave hazel leaves susceptible to the fungus known as fumagina (Capnodium sp.), which causes decreased photosynthesis, particularly during the period when the tree is storing reserves for the following season. Knowledge about the natural enemies of M. coryli in Chile is in its early stages compared with other countries where the hazelnut crop is more extensive. Indeed, only 13 entomophagous predators have been recorded in La Araucanía thus far, including one Hemerobiidae, one Syrphidae, one Cecidomyiidae and ten Coccinellidae. Of this last family, Adalia is the best represented genus, with three species. In this study, the life cycle of the Adalia angulifera Mulsant (Coleoptera: Coccinellidae) has been ascertained. M. coryli as its food, and the ability of the larvae to prey on the same aphid is presented here. This study took place under semi-controlled laboratory and greenhouse conditions in the Region of the Araucanía, Chile. This study showed that the average predatory capacity of the A. angulifera larvae was 127.60± 33.21 specimens of M. coryli. For each larval instar (L), it was determined that the daily average prey was 6.8 ± 2.45 aphids for L I; 14.64 ± 5.77 aphids for L II; 42.72 ± 17.12 aphids for L III and 63.44 ± 26.21 aphids for L IV.

En La Araucanía, el pulgón del avellano europeo, Myzocallis coryli (Goeze) es un áfido que puede ocasionar diversos daños al cultivo de Corylus avellana L., como reducción del tamaño de nuez, nueces vanas o favorecer en las hojas la aparición del hongo conocido como fumagina, Capnodium sp., el cual reduce la fotosíntesis, especialmente durante el periodo de acumulación de reservas del árbol para la temporada siguiente. El conocimiento sobre enemigos naturales de M. coryli en Chile es incipiente, comparado con otros países donde el cultivo del avellano europeo es extensivo; en efecto, para La Araucanía sólo se registran 13 entomófagos depredadores que corresponden a un Hemerobiidae, un Syrphidae, un Cecydomyiidae y diez Coccinellidae. De esta última familia, Adalia es el género más representado con tres especies. De Adalia angulifera Mulsant (Coleoptera: Coccinellidae) se ha dado a conocer su ciclo vital, con M. coryli como alimento y en esta ocasión se presenta la capacidad de depredación del estado larvario sobre el mismo áfido. El estudio se efectuó bajo condiciones semi controladas de laboratorio e invernadero en la Región de La Araucanía, Chile. Como resultado de este estudio se determinó que la capacidad de depredación del estado larvario de A. angulifera fue 127,60 ± 33,21 ejemplares de M. coryli para un periodo de 37,39 ±1,55 días; a su vez, para cada estadio larvario (L) se determinó que el promedio diario depredado fue para L I 6,8 ± 2,45 áfidos; L II 14,64 ± 5,77 áfidos; L III 42,72 ± 17, 12 áfidos y L IV 63,44 ± 26,21 áfidos.

Experimentos foram conduzidos em Paraúna, Goiás, Brasil, avaliando o impacto da mosca-branca na produção de soja. O delineamento experimental foi em blocos ao acaso, com quatro tratamentos e quatro repetições (10m x 20m). Os tratamentos foram diferentes níveis de infestação, obtidos pela aplicação de inseticidas em diferentes momentos; a testemunha foi mantida livre do ataque da praga, aplicando-se inseticida semanalmente. O número de insetos por folíolo foi avaliado semanalmente e, na colheita, foi avaliada a produtividade (kg ha-1) e o peso de 100 sementes (g). A soja foi tolerante à mosca-branca, visto que apenas o tratamento em que as ninfas por folíolo atingiram a média de 136,31±26,60 (tratamento sem aplicação de inseticidas) foi severo o suficiente para causar perdas de produtividade. Essa perda foi provavelmente associada à formação de fumagina, causada pelo fungo Capnodium sp., que se desenvolve nas secreções açucaradas produzidas pela mosca-branca na superfície das folhas. Portanto, inseticidas precisam apenas ser aplicados quando a infestação de mosca-branca for severa o suficiente para propiciar a formação de fumagina. Entretanto, a relação entre o número de insetos por folíolo e a formação de fumagina ainda precisa ser determinada para diferentes cultivares, assim como para diferentes condições ambientais.

Trials were carried out in Paraúna, Goiás, Brazil, to evaluate the impact of whitefly on soybean yield. The experimental design was a randomized block, with four treatments and four replications (10m x 20m). The treatments were different levels of infestation, managed by applying insecticide at different timing; the control was kept free of insects by weekly insecticide spraying. The number of insects per leaflet was evaluated weekly, and at harvest the yield (kg ha-1) and the weight of 100 seeds (g) were recorded. The soybean was tolerant to whitefly, since only the treatment where nymphs per leaflet reached 136.31±26.60 (treatment without the use of insecticides) was sufficiently severe to cause yield loss. This loss was likely associated with the sooty mold, caused by the fungus Capnodium sp. that develops in the sugary secretion produced by the whitefly on the surface of plant leaves. Therefore, insecticides should only be sprayed when a whitefly infestation is sufficiently severe to trigger the growth of sooty mold. The relationship between insect number per leaf and the growth of sooty mold still needs to be determined for different soybean cultivars, as well as for different environmental conditions.

O Vale do Ivinhema é a principal região produtora de mandioca de Mato Grosso do Sul. Todavia, o pequeno número de cultivares disponíveis nessa região vem contribuindo para baixas produtividades e crescente ocorrência de doenças e pragas. Com o objetivo de avaliar o comportamento de cultivares de mandioca nessa região, foram conduzidos, de julho/2005 a setembro/2006, experimentos em Nova Andradina, Ivinhema e Deodápolis, em delineamento em blocos casualizados, com quatro repetições. Foram avaliados 11 cultivares de mandioca quanto à produtividade e à incidência de fumagina causada pela mosca-branca (Bemisia sp.). Os cultivares IAC 12 e Fécula Branca apresentaram menor incidência de fumagina, enquanto o Cascuda destacou-se entre os de maior produção de raízes tuberosas e de massa seca em todos os ambientes.

The Ivinhema Valley is the most important region for cassava production in State of Mato Grosso do Sul. However, the restricted number of cultivars available for this region contributes for the occurrence of low yields and increasing diseases and pests. The objective of this study was to evaluate the performance of cassava genotypes in the region of Ivinhema Valley. The experiments were conducted from July/2005 to September/2006, in Nova Andradina, Ivinhema and Deodápolis in a randomized complete block design, with four replications. Yield components and resistance to sooty mould caused by whiteflies (Bemisia sp.) were evaluated in 11 cassava cultivars. It was found that the cultivars IAC 12 and Fécula Branca were the most resistant to sooty mould incidence. Cv. Cascuda showed the largest yield of storage roots and dry matter in all tested environments.

En los últimos cinco años la citricultura mundial y en particular la del hemisferio occidental ha estado amenazada por el arribo, dispersión y establecimiento de un psílido procedente de la región asiática: Diaphorina citri Kuwayama, que provoca cuantiosos daños en plantas de la familia Rutaceae, debido a que las ninfas y adultos extraen grandes cantidades de savia durante el proceso de alimentación, lo que propicia la formación de fumagina en la superficie de las hojas. Además, D. citri es un eficiente vector de la enfermedad denominada Huanglongbing, reconocida actualmente como la más destructiva para este cultivo, al reducir la producción sustancialmente y causar la muerte de la plantación en un periodo de cinco años. Se ha reconocido ya la presencia de la enfermedad en Brasil, Estados Unidos y otros países del Caribe, lo que ha puesto en estado de alerta a la región. Diversas han sido las estrategias de lucha para enfrentar el problema, desde el uso de antibióticos para el combate del agente causal Candidatus Liberibacter asiaticus, la aplicación de plaguicidas de origen químico contra el vector, el control biológico, hasta la erradicación de las plantas con síntomas característicos o que hayan sido diagnosticadas como positivas a la enfermedad; pero lo cierto es que ninguna de ellas ha brindado una solución eficaz hasta el momento y los países con más experiencia en el manejo de la misma han optado por convivir con ella y obtener frutos durante un tercio de la vida útil de las plantas. En el presente trabajo se ofrece una panorámica general sobre la problemática de D. citri y el agente causal de la enfermedad, dispersión y establecimiento en nuevas áreas, medidas de control adoptadas, entre otros aspectos, que sirven de complemento a la preparación técnica y actualización de productores e investigadores relacionados con la citricultura cubana.

In the last five years, the world citrus production, particularly the citrus from the western hemisphere, has been threatened by the arrival, dispersion and establishment of a psyllid coming from the Asian region: Diaphorina citri Kuwayama. This pest provokes considerable damages in Rutaceae family plants, due to nymphs and adults extract big quantities of sap during the feeding process allowing the presence of fumagine covering the leaf surface. Also, D. citri is an efficient vector of the disease called Huanglongbing, recognized as the most destructive for this cultivation, which can reduce production substantially and cause the death of the plantation in around five years. The presence of the disease has already been recognized in Brazil, United States and other Caribbean countries. Diverse strategies have been done to solve the problem, like the use of antibiotics against the causal agent Candidatus Liberibacter asiaticus, the chemical pesticide application for vector control, the biological control of the vector, until the eradication of plants with characteristic symptoms or positive to the disease; but certainly, none of them has offered an effective solution yet and the countries with more experience in the disease and vector management have chosen to cohabit with the problem and to obtain fruits during a third of plant lifespan. In this article, a general overview on D. citri and the causal agent of the disease, its dispersion and colonization to new areas, ways for its control, among other aspects have been offered, as a complement to the technical training, updating producers and researchers related with the Cuban citrus production.

Foi empregada a técnica de fluorescência de raios X por dispersão de energia (EDXRF), para estudar os efeitos da doença fumagina na composição química elementar de folhas. O arranjo experimental consistiu de um tubo de raios X com anodo de Mo (K<FONT FACE=Symbol>µ</FONT> = 17.44 keV) com filtro de Zr e um detector de Si(Li). As medidas foram realizadas com folhas de plantas cítricas infectadas e sadias. Foram quantificados os elementos Ti, Mn, Fe, Cu e Zn, com um limite de detecção médio de 69, 12, 8, 4 e 4 µg.g-1 respectivamente. As concentrações obtidas para o Fe variaram de 44 a 192 µg.g-1 em amostras de folhas sadias e de 363 a 704 µg g-1 para as folhas infectadas com fumagina.

Energy Dispersion X-Ray Fluorescence Technique (EDXRF) was employed to study the effects of the fumagina disease on the elementary chemical composition of the leaves. The experimental set up consisted of a Mo X-ray tube (Ksub<FONT FACE=Symbol>µ</FONT> = 17.44 keV) with Zr filter and a Si (Li) detector. The measurements were performed with the infected and healthy leaves of citric plants. The elements Ti, Mn, Fe, Cu and Zn were quantified, with an average DL of 69, 12, 8, 4 and 4 µg.g-1 respectively. The obtained concentration for Fe varied from 44 to 192 µg.g-1 in healthy leaves and from 363 to 704 µg.g-1 in infected leaves with fumagina .

La fumagina (Capnodium spp.) afecta a las plántulas de café durante la aclimatación. El objetivo de este estudio fue evaluar el efecto de un producto biológico obtenido de Burkholderia cepacia en el control de esta enfermedad. Se emplearon diferentes concentraciones del producto (50-250 mg L-1) para evaluar su efecto en la inhibición del crecimiento micelial de Capnodium spp. Se estudió el efecto del producto biológico sobre el índice de infección, crecimiento (pares de hojas, altura y peso seco), contenido de proteínas totales, fenoles y sobrevivencia de las plántulas. Los resultados mostraron una inhibición del crecimiento de Capnodium spp. hasta en un 79.3% (200 mg mL-1). Se logró el control total de la enfermedad (150 mg mL-1) en el clon M-28, del 95 y 90% en los clones M-229 y K-234 (150-200 mg mL-1). Además se observó un mejor comportamiento en los indicadores del crecimiento, proteínas, fenoles y sobrevivencia de las plántulas. Los resultados corroboraron la factibilidad del uso de este producto biológico para el control de la fumagina en plántulas de café durante la aclimatación.

Sooty molds (Capnodium spp.) affect coffee seedlings during acclimatization. The objective of this study was to evaluate the effect of a biological product obtained from Burkholderia cepacia for control of this disease. Different concentrations of the product (50-250 mg L-1) were used to evaluate its effect on mycelial growth inhibition of Capnodium spp., as well as the effect of the biological product on infection index, growth (pairs of leaves, height and dry weight), total protein content, phenolics, and seedling survival. The results showed growth inhibition of Capnodium spp. up to 79.3% (200 mg mL-1). Total control of the disease was obtained (150 mg L-1) on clone M-28, and 95 and 90% on clones M-229 and K-234 (150-200 mg mL-1), respectively. In addition, it was observed a better behavior of growth indicators: proteins, phenolics, and seedling survival. The results corroborated the feasibility of the use of this biological product for control of sooty molds in coffee seedlings during acclimatization.

É relatada pela primeira vez a ocorrência de Platycorypha nigrivirga Burckhardt (Hemiptera: Psyllidae, Acizzinae) no Brasil. A praga foi recentemente observada no Paraná, causando danos em folhas e brotações de Tipuana tipu (Benth.) em áreas urbanas. P. nigrivirga suga a seiva do floema e causa encarquilhamento, manchas e queda de folhas. Seus excrementos se acumulam sobre as folhas propiciando o aparecimento de fumagina ou caem em grande quantidade sobre os carros sujando-os como se fossem respingos de tinta branca e pegajosa.

The occurrence of Platycorypha nigrivirga Burckhardt (Hemiptera: Psyllidae, Acizzinae), is reported for the first time, in Brazil. The psyllid was observed causing injuries on leaves and shoots of Tipuana tipu (Benth.), in urban areas of Paraná State. P. nigrivirga are tiny sap-sucking insects that feed on phloem and cause curling, stains and fall of leaves. The excrements of these insects accumulate on the leaves propitiating fungus growth on the leaves, or they fall in great amount on the cars dirtying them as if they were sparkling of white and sticky ink.

The woolly whitefly Aleurothrixus floccosus (Maskell), and the red citrus red mite Panonychus citri (McGregor), are considered serious citrus pests which may cause economic damage, and the use of non selective insecticides increases the problem due to the effect on the natural enemies. To evaluate the use of detergent based on sodium benzene sulfonate on the reduction of whiteflies, mites and natural enemies, experiments were performed in two citrus orchards. The first field trial was carried out on in a mandarin orchard (Citrus reticulata Blanco) infested by the woolly whitefly at El Palqui (IV Region, Chile). The experiment consisted of the evaluation of two applications of detergent (February 10th and March 3rd, 1998), compared with an untreated control. The results showed significant differences in A. floccosus populations between sprayed and untreated trees from May to July. The mean of parasitized nymphs between March and August was 89.6% in treated trees and 57.1% in untreated trees. The proportion of fruits at harvest with sooty mould was lower on untreated trees compared with the control, 2.3% and 45.5%, respectively. The second field trial was carried out on an orange orchard trees (Citrus sinensis (L.) Osbeck), infested by the citrus red mite at Hijuelas (V Region) and included the following applications detergent, chinometionate, mineral oil and water. Chinometionate produced an effective control of the phytophagous mites populations and an almost total elimination of natural enemies such as phytoseiids and the coccinellid Stethorus histrioChazeau. The application of detergent and mineral oil showed less control compared to the acaricide and less impact on populations of natural enemies.

La mosquita blanca Aleurothrixus floccosus (Maskell) y la arañita roja Panonychus citri (McGregor) son consideradas plagas que causan daños económicos a los cítricos, y el uso de insecticidas no selectivos aumenta el problema por su efecto sobre los enemigos naturales. Para evaluar el uso del detergente en base a benceno sulfonato de sodio en la reducción de mosquitas blancas, arañitas y sus enemigos naturales se desarrollaron experimentos en dos huertos de cítricos. El primer ensayo fue realizado en un huerto de mandarinos (Citrus reticulata Blanco) infestado con mosquitas blancas en El Palqui (IV Región). El experimento consistió en la evaluación de dos aplicaciones del detergente (10 de febrero y 3 de marzo de 1998), comparado con un control sin aplicación. Los resultados mostraron diferencias significativas en la presencia de A. floccosus entre árboles asperjados y no asperjados, desde mayo a julio. Entre marzo y agosto de 1998 el promedio de ninfas parasitadas en los árboles tratados fue de 89,6 y de 57,1% en las plantas sin lavar. La proporción de frutos manchados con fumagina en la cosecha fue menor en los árboles asperjados comparados con el control, 2,3 y 45,5%, respectivamente. El segundo ensayo fue realizado en un huerto de naranjos (Citrus sinensis (L.) Osbeck) infestado con arañita roja de los cítricos en Hijuelas (V Región) y consideró la aplicación de: detergente, chinometionate, aceite mineral y agua. Chinometionate produjo un efectivo control de las arañitas fitófagas y una eliminación casi total de sus enemigos naturales representados por fitoseidos y el coccinélido Stethorus histrio Chazeau. La aplicación del detergente y el aceite mineral mostraron una actividad inferior al acaricida y un impacto menor sobre las poblaciones de enemigos naturales.

O objetivo do presente estudo foi avaliar os efeitos da fumagina na anatomia e a atividade fotoquímica em folhas de mogno (Swietenia macrophylla King., Meliaceae). Folhas com e sem fumagina desenvolvidas na sombra foram comparadas com as de folhas de sol, para verificar as diferenças em parâmetros fotoquímicos utilizando-se medidas de fluorescência. As amostras de folhas destinadas a estudos anatômicos foram processadas segundo técnicas convencionais. A intensidade de bloqueio da radiação densidade de fótons fotossinteticamente ativos (DFFA) pela fumagina e seu efeito sobre a atividade fotoquímica foram avaliados. As folhas de sol têm mesofilo espesso e parênquima paliçádico unisseriado enquanto nas folhas de sombra o mesofilo é delgado, independentemente da presença ou não de fumagina. O rendimento quântico efetivo (deltaF/Fm') e a taxa aparente de transporte de elétrons (ETR) das folhas de sol foram superiores às das folhas de sombra. Os valores de ETR sugerem que, nas plantas crescidas na sombra, a saturação da atividade fotoquímica ocorre em menores valores de DFFA. Observaram-se menores valores de deltaF/Fm' nas folhas com fumagina e, conseqüentemente menores valores de ETR. A presença de fumagina promoveu bloqueio de 40% na luz incidente e, conseqüentemente, presume-se um decréscimo adicional nos valores de ETR. Pelos dados, verifica-se que a presença de fumagina não promoveu danos diretos nas folhas, mas reduz a capacidade fotoquímica por diminuir a disponibilidade de luz.

The aim of present study was to evaluate the effects of the sooty mold on anatomy and photochemical activity of mahogany (Swietenia macrophylla) leaves. The photochemical features of shade-developed leaves with or without sooty mold were compared to those of sun leaves using chlorophyll a fluorescence measurements. Leaf anatomy was also evaluated using conventional techniques. The degree of blockage of the photosynthetic active photon flux density (PPFD) by sooty mold and its effect on photochemistry were evaluated. Sun leaves showed thick mesophyll with palisade parenchyma disposed in a uniseriate layer, whereas shade leaves showed narrow mesophyll, independently of sooty mold presence. The effective quantum yield (deltaF/Fm') and the apparent electron transport rate (ETR) of sun leaves were higher than those of shade leaves. The values of ETR suggested that photochemistry saturation occurred at lower PPFD in shade-grown plants. Lower values of the deltaF/Fm' and, consequently, lower values of ETR were observed in leaves with sooty mold. A reduction of 40% of the incident light was seen due to physical blockage by sooty mold which is presumably responsible for an additional decrease of ETR values. Our data indicated that sooty mold did not directly damage the leaf, but reduce leaf photochemistry capacity, by decreasing light availability.

O pulgão-gigante-do-pinus, Cinara atlantica (Wilson, 1919) (Hemiptera, Aphididae), é considerado atualmente uma das principais pragas dos reflorestamentos de pinus no Brasil. Como a informação sobre os danos causados por esta praga é restrita, esta pesquisa teve como objetivo caracterizar e quantificar os danos de C. atlantica em Pinus taeda. O experimento foi desenvolvido em casa de vegetação, seguindo um delineamento inteiramente casualizado. Foram testados três níveis de infestação com densidades populacionais de zero (testemunha protegida com inseticida) 10 ± 2, 20 ± 2 e 50 ± 2 afídeos por muda de P. taeda com idades de 90 e 150 dias. As mudas atacadas apresentaram redução no desenvolvimento, entortamento do fuste, superbrotação e presença abundante de fumagina devido ao desenvolvimento de fungo sobre o honeydew eliminado pelos afídeos. O diâmetro do colo diminuiu significativamente em 16,1% na densidade de 50 ± 2 afídeos/planta, nas mudas com 90 dias, quando comparado à testemunha. Nas mudas com 150 dias não houve diferença significativa no diâmetro do colo entre as parcelas infestadas e a testemunha. Houve uma redução de 24,4% na altura das mudas de 90 dias com a densidade de 50 ± 2 afídeos e 32,6% nas mudas de 150 dias, com intensidade de 20 ± 2 afídeos.

The giant conifer aphid, Cinara atlantica (Wilson, 1919) (Hemiptera, Aphididae), is one of the main insect pests on pine reforestation areas in Southern Brazil, nowadays. Since there is very few information about its damage, the objective of this study was to characterize and quantify the damage of C. atlantica on Pinus taeda. The experiment was carried out in a greenhouse, using a random design, with three infestation levels: 0 (control), 10 ± 2, 20 ± 2 and 50 ± 2 aphids on each P. taeda seedling of 90 and 150 days old, with 20 replicates/treatment. The main damage observed were stunting, twisting, oversprouting and large amount of sooty mold on honeydew. The basal diameter was significantly reduced by 16.1% under 50 ± 2 aphids/plant of 90 days compared to the control. For the 150 days old seedlings, there was no statistical difference between the infestation levels. The plant height reduction was of 24.4% for the 90 days old plants with 50 ± 2 aphids and 32.6% for the 150 days old with 20 ± 2 aphids.

Palmeiras do gênero Archontophoenix, utilizadas tanto como ornamentais quanto produtoras de palmito de qualidade, são susceptíveis à fumagina, doença associada à infestação por pulgões, que afeta a fotossíntese, o crescimento e a aparência das plantas. Foram avaliados a campo a resistência à fumagina conjuntamente com três caracteres associados ao crescimento em 24 famílias de meios-irmãos, 28 meses após o plantio, a fim de identificar a variabilidade genética para os caracteres resistência à fumagina, altura, diâmetro e número de folhas; estimar as correlações genotípicas e fenotípicas envolvendo esses quatro caracteres; e aplicar a estratégia de seleção usando o índice multiefeitos. Houve diferenças entre as famílias para os caracteres avaliados, sugerindo a possibilidade de seleção. O baixo coeficiente de variação observado para resistência à fumagina (9,48%) indica que o método de avaliação adotado, baseado em escala de notas após observação visual, foi eficiente e prático para comparar níveis de infestação do complexo fungo+pulgão em palmeiras do gênero Archontophoenix. As estimativas da herdabilidade no sentido restrito foram baixas a médias para os caracteres relacionados ao crescimento (0,10, 0,26 e 0,26 para número de folhas, diâmetro e altura da planta, respectivamente) e muito altas (0,91) para resistência à fumagina. Correlação genética positiva foi observada entre resistência à fumagina e altura da planta, indicando que a eliminação de plantas muito susceptíveis pode ser feita sem interferência na seleção indireta para produção de palmito. A estratégia de seleção pelo índice multiefeitos (com ganhos genéticos esperados variando de 6,23 a 11,83%) mostrou-se adequada para melhorar simultaneamente caracteres relacionados ao crescimento e à produção de palmito.

Archontophoenix palms, utilized both as ornamental species and as a source of high-quality heart of palm, are susceptible to sooty mold, a disease coupled with aphid infestation, which affects photosynthesis and causes unpleasant, darkish palm appearance. Scoring rates for sooty mold resistance and three growth traits were assessed under field conditions in 24 open-pollinated half-sibs families, 28 months after planting, aiming to identify genetic variability for sooty mold resistance; estimate genetic parameters for this trait and plant height, diameter and number of leaves; estimate genetic and phenotypic correlation for the four traits and evaluate selection methods for heart of palm production through multi-trait index selection based on growth traits. There were genetic differences among families for all traits. The low coefficient of variation for sooty mold (9.48%) indicates that the visual rating method adopted was effective and feasible for comparing aphid plus sooty mold infestation levels in Archontophoenix. Narrow sense heritability estimates were low and medium for growth traits (0.10, 0.26 and 0.26 for leaves number, plant diameter and height, respectively) and very high (0.91) for sooty mold resistance. Genetic correlation was found between sooty mold resistance and plant height. This positive relationship indicates that culling of very susceptible palms can be done possibily without interference in the follow up indirect selection for heart of palm yield. Some selection strategies were presented, showing that possible genetic gain could range from 6.23 to 11.83%, depending on the selection method adopted and on the effective restriction of the population size.