Cecília Helena Silvino Prata Ritzinger

Manejo integrado de nematóides na cultura da bananeira

The integrated management is a requirement of the European Community (CE) which demands rigorous quality product and sustainability, which is emphasized primarily on the environment protection, food safety, work conditions, human health and economical viability. In this context, the use of organic amendments for soil management is one of the strategies that brings the most benefits to soil biodiversity and conservation. This practice is known since the beginning of the civilization. Nevertheless, an effective use still depends on the knowledge of the many interactions in the agro-ecosystem. This review presents some studies of its use in integrated management of plant parasitic nematodes, validation perspectives focused in banana and use possibilities to assist the sustainability demand.

Nematoides: bioindicadores de sustentabilidade e mudanças edafoclimáticas

Em vista do desconhecimento da importância economica dos fitonematoides, isoladamente, em cada cultura, esses organismos tem sido frequentemente negligenciados nos agroecossistemas, somente assumindo status de patogeno quando sua populacao se encontra muito elevada, com prejuizos acentuados. Contudo, somente 10% do universo de nematoides causam danos as plantas, 25% sao nematoides agrupados nos niveis troficos de fungivoros ou micofagos, bacterivoros e onivoros, de acordo com o tipo de sua alimentacao. Nao se conhece a relacao do nivel populacional do nematoide com o nivel de dano nas plantas. Por esse motivo, os defensivos quimicos sao, em sua maioria, a opcao mais usada ou a preferida pelos agricultores, para o manejo, podendo promover o desequilibrio na comunidade, refletindo em risco ambiental. Para a avaliacao de risco, proveniente de substâncias quimicas, impactos sobre diferentes tipos de manejo dos solos, bem como disturbios que eles sofrem, varios testes de toxicidade com nematoides tem sido realizados e ha crescente demanda em sua utilizacao em paises mais desenvolvidos. A analise da comunidade presente em determinado ecossistema, de acordo com os habitos alimentares e o indice de maturidade, provou ser bom indicador a danos causados por poluentes ou disturbios ecologicos. Nessa revisao, sao apresentados dados que demonstram que esses organismos podem ser utilizados de forma satisfatoria em estudos de sustentabilidade de ecossistemas, devido a sua abundância, diversidade e respostas a toxicidade e disturbios ambientais.

Fitonematoides associados a bananais 'Pacovan' sob condição de cultivo irrigado: relação com a produção

Among the factors that affect the productivity of banana, stand out pests, diseases and inadequate cultural practices. In this context, plant parasitic nematodes have great importance for reducing the efficiency of water and soil nutrients absorption by the roots, causing the plants to fall down near harvest. About 146 nematode species have already been reported associated to banana roots. Nevertheless, only Radopholus similis, several species of the genus Meloidogyne, Helicotylenchus, Pratylenchus and Rotylenchulus cause significant losses in banana plantations. In plantations located in irrigated areas in the municipal districts of Petrolina/PE and Juazeiro/BA, questionnaires were applied to obtain information about the history of the area, including plant nutrition, fertility, cultural practices, incidence of pests and post-harvesting practices. It was observed that 90% of the area belonged to small farmers. The major problems pointed out were: inadequate management, including harvesting and post-harvesting practices, presence of nematodes and strong winds. In this research a survey of the occurrence of plant parasitic nematodes was carried out. Thus, this research aimed to identify the genera of the plant parasitic nematodes found, and to study the relationship between the banana production in the several selected areas with the population of plant parasitic nematodes in the soil and in the banana root system. In each selected area, 20 banana plants were marked and samples of soil and roots were taken. Each sample was composed of four samples of each plant to represent the population of nematodes. The genera of the most abundant nematodes were Helicotylenchus, Meloidogyne and Rotylenchulus. Nevertheless, the production was neither related to the number of farms in each location, nor with the plant parasitic nematode density (Helicotylenchus sp., Meloidogyne sp., Rotylenchulus sp., Pratylenchus sp. and Radopholus similis) associated with the soil or banana roots. It could be inferred that the cultural practices adopted in each location of irrigated banana production had a positive influence on the banana production (weight of bunches) under different plant parasitic nematode populations.

Cultivos intercalares e controle de plantas daninhas em plantios de maracujá-amarelo

This work aimed identifying crops for intercropping and integrated methods for weed control in yellow passion fruit (Passiflora edulis Sims f. flavicarpa Deg.) orchard, that will favor its production and profitability. The experiment was set up in May 1999, with the plants being conducted by a vertical support structure with one wire extended 2.0 m above the soil surface, and distributed in a spacing of 2.5 m x 5.0 m. The experimental design was in randomized blocks, with four replications and six treatments as follows: T1 - maize (Zea mays L. , cv. BR 106) as intercrop; T2 - bean (Phaseolus vulgaris L., cv. Perola) as intercrop; T3 - pork bean (Canavalia ensiformis L.) in the interspace and hoeing in the plant lines; T4 - pork bean in the interspace and chemical weed control in the plant lines (glyphosate at 1.5 kg./ha); T5 - general chemical weed control (alachlor at 2.8 kg/ha + diuron at 1.2 kg/ha in pre-emergence and glyphosate at 1.5 kg/ha in post-emergence); T6 - control (general hoeing). Data obtained during the harvest period (May 1999 to April 2000) showed no statistical differences among treatments for yield (industry), fruit weight, length and diameter, total soluble solids and total titrable acidity. However, there was a statistical significance for total yield and yield for the fresh fruit market, with best results for bean as intercrop, giving a passion fruit yield of 12.82 t/ha. Both bean and maize should be recommended as intercrops during the first year of passion fruit cycle. The herbicides used both in pre- and post-emergence were economically viable and did not show toxic effects on the yellow passion fruit plants.

Advances in the propagation of acerola

The acerola tree (Malpighia emarginata Sessé & Moc. ex DC.) is a fruit species that has prospered in the Brazilian tropical regions, especially in the Northeast, thanks to the high content of vitamin C in the fruits, among other characteristics that make it attractive to the producer, such as early production. Although there is increasing demand for the product, the production of certified seedlings of good commercial varieties is still a barrier to further expansion of the crop. This review aims to present, in a comprehensive way, technical information on how the spread has been made since its introduction in the country, as well as innovations and advances. Traditionally, propagation is carried out through seeds, cuttings and by grafting on top of common acerola rootstocks, with no defined origin. The advances presented are focused on the use of new canopy and rootstock varieties, including the use of double grafting, minicutting and tissue culture, with studies still in progress, and use of new substrates such as coconut fiber.

Impact of castor meal on root-knot and free-living nematodes

Soil amendment may enhance soil quality as well as reduce plant-parasitic nematode. Despite the many applications already undertaken using castor meal, its efficiency in controlling root-knot nematodes (RKN, Meloidogyne incognita) when applied to melon (Cucumis melo) is still not clear. Three different amounts of castor meal (Ricinus communis) applied were evaluated in microplots planted with melon either with or without RKN. The impact of castor meal on soil free-living nematode communities was also determined. Total nematode genera richness was estimated as 37 for the entire set of microplots sampled across both sampling dates. Rarefaction analysis resulted in 12 collectors curves out of the total of 30 that reached the horizontal asymptote. Univariate ANOVA with two factors yielded differences (p < 0.05) only with regard to the time factor. Simpson, Shannon, Evenness and Equitability indices showed a trend toward moderate increases by the end of the experiment, while the other indices were higher for tomato in pre-transplant sampling compared to harvest. Nematode community and diversity changed during the course of the experiment, although there was substantial confounding heterogeneity within and between the factorial combinations from the beginning. Root knot population was not reduced by the castor meal but increased throughout the period, regardless of treatment. RKN reduced melon yield, number and weight of melon.

Torta de mamona no controle da broca-do-rizoma (Cosmopolites sordidus) em bananeira-Terra

The aim of this study was to evaluate the effects of castor bean pie on the infestation by Cosmopolites sordidus and on the development of banana plants cv. Terra. To observe the dose-response relationship, each treatment focused on a different dosage of castor bean pie (0 g, 12 g, 15 g, 18 g, 24 g) applied every two months to the banana plants, starting from the planting date. The experimental design was completely randomized with ten replicates. Plant vegetative growth was evaluated by measuring plant height, pseudostem diameter, and counting alive (or green) leaves. The infestation of plants was undertaken by using 25 adults of C. sordidus per plant. Six months after planting, the percentage of damage caused was scored on rhizomes and the number of adults (alive and died), larvae, and pupae was registered. Absorbance related to the leaf chlorophyll content was also determined by a chorophyllometer. In plants treated with castor bean pie there was a low infestation of the banana weevil borer. Vegetative growth and absorbance were also positively affected by applying castor bean pie. Therefore, castor bean pie reduces C. sordidus population in rhizomes of bananas cv. Terra, improving vegetative growth and chlorophyll content in leaves.