Cláudia Araújo Marco

The Impact of Organic Farming on Quality of Tomatoes Is Associated to Increased Oxidative Stress during Fruit Development

This study was conducted with the objective of testing the hypothesis that tomato fruits from organic farming accumulate more nutritional compounds, such as phenolics and vitamin C as a consequence of the stressing conditions associated with farming system. Growth was reduced in fruits from organic farming while titratable acidity, the soluble solids content and the concentrations in vitamin C were respectively +29%, +57% and +55% higher at the stage of commercial maturity. At that time, the total phenolic content was +139% higher than in the fruits from conventional farming which seems consistent with the more than two times higher activity of phenylalanine ammonia lyase (PAL) we observed throughout fruit development in fruits from organic farming. Cell membrane lipid peroxidation (LPO) degree was 60% higher in organic tomatoes. SOD activity was also dramatically higher in the fruits from organic farming. Taken together, our observations suggest that tomato fruits from organic farming experienced stressing conditions that resulted in oxidative stress and the accumulation of higher concentrations of soluble solids as sugars and other compounds contributing to fruit nutritional quality such as vitamin C and phenolic compounds.

Características do óleo essencial de capim-citronela em função de espaçamento, altura e época de corte

Citronella grass (Cymbopogon winterianum Jowitt.) has grown in importance due to an increasing demand of the essential oil. The influence of spacing (50 x 50; 50 x 80 e 80 x 80 cm), cutting height (15 and 30 cm above ground) and harvesting season (four, six and eight months after planting) on productivity and essential oil quality was evaluated. The study. occurred in field, in Pentecoste, Ceara State, Brazil, from September 2002 to September 2003. The treatments were organized in a factorial 3 x 3 x 2 scheme, in randomized block design, with three replicates. Cutting plants four months after planting date resulted in significantly higher essential oil production when cut at 30 cm height. Six months after planting date, higher yield was obtained at 15 cm height. The cutting height did not influence essential oil production when plants were harvested after eight months. Using larger plant spacing (80 x 80 cm) resulted in significantly higher essential oil production when plants were cut at 15 cm, divergent to the result observed with minor spacing (50 x 50 cm). The citronellol + citronellal content was significantly higher in plants cultivated at intermediate spacing and cut after six months at a height of 30 cm. The geraniol content, however, was higher in plants harvested after four months, with no influence of spacing or cutting height.

Chemical Composition and Allelopathyc Activity of Essential Oil of Lippia sidoides Cham

La alelopatia es un proceso mediante el cual productos metabolicos secundarios, tales como terpenos fenoles, producidos por una planta en particular interfieren significativamente, y de manera antagonica, en el desarrollo de otras especies vegetales. Nuestros objetivos fueron caracterizar quimicamente el aceite esencial de Lippia sidoides Cham., cultivada en la region de Cariri Ceara, y evaluar el efecto alelopatico del aceite aplicado en pre-siembra en la germinacion de lechuga (Lactuca sativa L.), rucula (Eruca sativa Mill.), y col rizada (Brassica oleracea L.). El principal constituyente del aceite esencial fue el monoterpeno timol (84,90%). Los experimentos fueron conducidos en bloques completos al azar en esquema factorial 4 x 3 con cuatro combinaciones de aceites esenciales aplicados en tres especies diferentes en pre-siembra. Se analizaron las siguientes variables: indice de velocidad de emergencia (EVI), porcentaje de germinacion y el tiempo medio de germinacion (MTG), los recuentos se llevaron a cabo todos los dias hasta el decimocuarto dia despues de la siembra. A traves de analisis cualitativos realizados por cromatografia de gases acoplada a espectrometria de masas (GC/ ME) fueron identificados componentes quimicos que representan 97,82% del aceite esencial de L. sidoides, siendo constituyente mas concentrado timol (84,90%). Se comprobaron efectos alelopaticos negativos en lechuga, debido a que esta mostro un bajo EVI y un alto MTG.

Efeito de substratos na formação de porta-enxertos de Psidium guajava L. cv. Ogawa em tubetes

The formation of guava rootstocks in root plugs was evaluated in differents substrates: vermiculite + vermicompost, carbonized rice hulls + vermicompost, vermicompost + decompose cashewnut tegument, carbonized rice hulls + cattle manure, carbonized rice hulls + vermiculite and dust peel of ripened coconut fruit + decompose leave dust from carnauba palm tree. The experimental design was completely randomized with 6 treatments, 4 replicates and 14 plants per plot. The plant height, stem diameter and number of leaves were measured in three different periods at 60, 90 and 120 days after sowing. Shoot dry matter and root dry matter mass, the facility to remove the seedling from the root plug and substrates aggregation to root were evaluated at 120 days after sowing. The results showed that guava rootstocks with 120 days provided the taller plant height (30.2 cm), stem diameter (5.3 mm), dry matter mass (5.7g), root dry matter mass (3.0 g) and number of leaves (14.5) in the vermiculite + vermicompost substrate. The easiest substrate to take out the rootstocks from the root plug were achieved using vermiculite + vermicompost, vermicompost + decompose cashwewnut tegument, carbonized rice hulls + vermiculite and carbonized rice hulls + cattle manure. It was observed that all the substrates showed excellent results in substrate aggregation.

Inoculation efficiency of Azospirillum brasilense on economising nitrogen fertiliser in landrace popcorn

Nitrogen is one of the nutrients most demandedby popcorn, and one that most increases production costs. Considering these factors, the aim of this study was to evaluate the effectiveness of inoculatingpopcorn seeds with Azospirillum brasilense together with four levels of nitrogen fertiliser, and its contribution to characteristics related to production. The experiment was carried out in the experimental area of the Centre for Agrarian Sciences and Biodiversity of the Federal University of Cariri, in Crato, in the State of Ceara. Eight treatments were evaluated with four replications, using an experimental design of randomised blocks in a 2x4 factorial scheme corresponding to the presence and absence of inoculation, and to four doses of nitrogen as top dressing. The following characteristics were evaluated: plant height, height of ear insertion, number of plants, number of lodged plants, number of broken plants, number of poorly husked ears, ear diameter, ear length, number of ears, number of diseased ears, number of infested ears, grain productivity, ear weight, mean 100-grain weight, and expansion capacity. There were significant differences for most of the characteristics under evaluation, with an increase of 17.18% in the number of ears and 10.78% in grain productivity, reducing the top dressing to 50 kg ha-1 in the presence of A. brasiliensi. These results demonstrate the potential for economisingnitrogen fertiliser in popcorn production under the soil and climate conditions of the Cariri region of the State of Ceara.

Larvicide activity of essential oils on Aedes aegypti L. (Díptera: Culicidae)

espanolAedes aegypti L. es el mosquito de salud publica mas importante del mundo. Esto es debido a que es un transmisor del virus que causa muchas enfermedades, especificamente el dengue. Tradicionalmente, el uso intensivo de insecticidas ha sido la estrategia principal para eliminar los mosquitos adultos o sus larvas; Sin embargo el uso intensivo de insecticidas puede estimular una resistencia en los mosquitos y danos a la salud o al medio ambiente. Los aceites esenciales de plantas medicinales se habian mostrado de alta eficiencia como larvicidas alternativos. Por lo tanto, evaluamos la eficiencia de los aceites esenciales de Vanillosmopsis arborea y Hyptis suaveolens en larvas de Aedes aegypti. Los aceites esenciales se extrajeron mediante el metodo de hidrodestila-cion utilizando un equipo Clevenger. Se utilizo un diseno completamente al azar (CRD) utilizando un factorial 2x5 que el aceite esencial de V. arborea y H. suaveolens a concentraciones de cinco concentraciones (200, 150, 100, 50 y 0 ppm) respectivamente. Cada uno de los diez tratamientos se replico cuatro veces utilizando diez larvas cada uno, totalizando 40 muestras. CL W CL50, CL(9)0, ensayo promedio, analisis de regresion y eficiencia. El aceite de V. arborea mostro valores de CL W = 39,69 ppm, CL50 = 48,98ppm y CL90 = 60,45 ppm, mientras que el aceite de H. suaveolens mostro valores de CL W = 78,46ppm, CL50 = 139,7 ppm y CL90 246,48 ppm. El principal componente quimico de V. arborea fue a-bisabolol (94,17%), mientras que para H. suaveolens fue 1,8-cineol (72,23%). Ambos aceites esenciales probados mostraron efecto larvicida sobre las larvas de A. aegypti EnglishAedes aegypti L. is the most important mosquito in terms of public health in the world. It transmits a virus that causes several diseases, among them, dengue fever. Traditionally, the intensive use of insecticides has been the main strategy to control A. aegypti and to eliminate adult mosquitos or their larvae; however, this may lead to resistance by the mosquitos and damages to human health and the environment. Essential oils from medicinal plants have shown high efficiency as alternative larvicides. Therefore, the objective of this paper was to evaluate the larvicide potential of Vanillosmopsis arborea and Hyptis suaveolens on Aedes aegypti larvae. The essential oils were extracted by the hydrodistillation method using a Clevenger equipment. The completely randomized design (CRD) was used with a 2x5 factorial, with two essential oils and five concentration levels (200; 150; 100; 50; and 0 ppm). Each one of the ten treatments was replicated four times with ten larvae each, totaling 40 plots. Analyses were made regarding LC10, LC50, LC90, test of means, and regression and efficiency analysss. The V. arborea oil showed values of LC W = 39.69 ppm, LC50 = 48.98 ppm, and LC90 = 60.45 ppm, while the H. suaveolens oil showed values of LC W = 78.46 ppm, LC50 = 139.7 ppm and LC90 = 246.48 ppm. The main chemical component of V. arborea was a-bisabolol (94.17%), while for H. suaveolens, it was 1,8-cineol (72.23%). The essential oils showed a larvicide effect on A. aegypti larvae

Yellow melon production under different densities of plantation.

The experiment was carried out in Aracati-CE, with drip irrigation system. The objective of the work was to evaluate the effects of the planting density (10; 12.5; 16.6 and 25 thousand plants ha -1 ) on the productivity of melon fruits, hybrid TP1109. The densities were obtained by keeping constant the spacing among rows (2.0 m) and by varying the spacing 1 Autor para correspondência Parte da monografia apresentada pelo primeiro autor ao curso de Especialização em Fruticultura Irrigada CENTEC– Limoeiro do Norte-CE 2Especialista em Fruticultura Irrigada, Itaueira Agropecuária S/A, itaprod@itaueira.com.br 3Professor Adjunto, Universidade Federal do Ceará, carloswagner@ufc.br 4 Professor do IFCE Campus Limoeiro do Norte, fco_limeira@yahoo.com.br 5 Professor do IFCE Campus Limoeiro do Norte, sildemberny@hotmail.com 6 Professor Adjunto, Universidade Federal do Ceará, clmarko@ufc.brO experimento foi realizado em Aracati-CE, com irrigacao localizada por gotejamento. O objetivo do trabalho foi avaliar os efeitos da densidade de plantio (10; 12,5; 16,6 e 25 mil plantas ha-1) sobre o rendimento de frutos do meloeiro amarelo, hibrido TP1109. As densidades foram obtidas mantendo-se constante o espacamento entre fileiras (2,0 m) e variando-se o espacamento entre plantas (0,50; 0,40; 0,30 e 0,20 m). Foram avaliados o peso por fruto (kg/fruto), numero de frutos por planta, producao comercial (kg/ha), solidos soluveis totais (Brix) e classificacao de frutos por tipo comercial. Utilizou-se o delineamento em blocos ao acaso, com tres blocos e quatro repeticoes. Com a reducao da densidade de plantio, o peso por fruto apresentou efeito linear positivo. O espacamento de 0,50 m, com duas plantas por metro linear, apresentou maior peso por fruto com 1,51 kg fruta-1. Com o aumento do espacamento de plantio registrou-se maior numero de frutos por planta. A densidade de plantio nao influenciou a producao comercial, bem como nao afetou o teor de solidos soluveis totais. Menores densidades promoveram um maior percentual (> 67%) de frutos do tipo 7 ou inferior.