ResumoO objetivo deste trabalho foi caracterizar a macrofauna edáfica e avaliar os efeitos ocasionados em virtude do método de colheita e aplicação de vinhaça em áreas de cana-de-açúcar comparativamente com uma área de mata. O delineamento experimental foi inteiramente casualizado, com cinco tratamentos (colheita manual com uso do fogo e mecanizada sem uso do fogo associadas ou não à aplicação de vinhaça em adubação, e mata) e cinco repetições durante seis épocas amostrais. Retiraram-se monólitos de 25 cm x 25 cm x 30 cm, sendo os organismos do solo coletados e classificados em grupos e/ou ordem. A caracterização dos grupos nos tratamentos foi realizada por análise de componentes principais. Após o cálculo da densidade de organismos, dos índices ecológicos de diversidade (Shannon), equitabilidade (Pielou) e riqueza de grupos, os valores foram comparados através do teste Duncan ou Kruskal-Wallis a 5%. Comparativamente com as áreas de cana-de-açúcar, a área de mata apresenta maiores valores dos índices calculados. Os tratamentos de cana-de-açúcar com manutenção da cobertura e/ou aplicação de vinhaça favorecem a fauna edáfica. Palavras-chave: Saccharum officinarum, fauna edáfica, palhada, vinhaça, mata
AbstractThe objective of this study was to characterize the soil fauna and assessing the effects of harvest method and vinasse application in areas of sugar cane compared to a forest area. The experimental design was completely randomized with five treatments (manual harvesting with use of fire and mechanical harvesting without use of fire associate to or not vinasse application fertilizer and forest), five repetitions for six sampling times. Retired monoliths 25 cm x 25 cm x 30 cm, where soil organisms were sorted and classified into groups and /or order. The characterization of the treatments was performed by principal component analysis. Having previously calculated the density of organisms, the ecological indices of diversity (Shannon), evenness (Pielou) and richness of groups, these were compared by Duncan or Kruskal-Wallis test at 5%. Compared with the areas of sugar cane , the forest area has the highest calculated indices. The treatments of sugar cane with maintenance of straw and /or vinasse application favor soil fauna.
The effect of aromatic plants on number of twospotted spider mite (TSSM), Tetranychus urticae Koch, when intercropped with strawberry were assessed in the field. During the first year, chives (Allium schoenoprasum L.), coriander (Coriandrum sativum L.), fennel (Foeniculum vulgare Mill.), garlic (Allium sativum L.), oregano (Origanum vulgare L.), or sweet marjoram (Origanum majorana L.) were intercropped with strawberry. Assessments were performed on TSSM populations by taking six samples from July 20 to September 20, 2012. During the second year, garlic plants were intercropped between rows of strawberry at three densities in greenhouse and field. Mobile forms and eggs numbers (only in field) of TSSM were evaluated from April 18 to June 05 (greenhouse) and June 06 to August 14, 2013 (field). It was found that intercropping with garlic caused a greater reduction of TSSM (up to 52 %) in strawberry plants when higher populations of TSSM occurred in the field. TSSM reduction was found in one sample when fennel and chives were intercropped with strawberries (42 and 50 % reduction, respectively); this also occurred when populations of TSSM were higher. The three densities of garlic plants (one, two and three rows among the strawberry rows) reduced TSSM mobile forms by 49, 53 and 60 % (greenhouse) and 44, 51 and 65 % (field), and eggs by 38, 43 and 64 % (field), respectively. The results suggest that intercropping garlic plants between strawberry rows is a promising strategy to reduce TSSM populations.
The diverse flora of the Atlantic Forest is fertile ground for discovering new chemical structures with insecticidal activity. The presence of species belonging to the genus Baccharis is of particular interest, as these species have shown promise in pest management applications. The objective of this study is to chemically identify the constituents expressed in the leaves of seven species of Baccharis (B. anomala DC., B. calvescens DC., B. mesoneura DC., B. milleflora DC., B. oblongifolia Pers., B. trimera (Less) DC. and B. uncinella DC.) and to evaluate the toxicological and morphological effects caused by essential oils (EOs) on the larvae and adults of Drosophila suzukii (Diptera: Drosophilidae). Chemical analysis using gas chromatography-mass spectrometry (GC–MS) indicated that limonene was the main common constituent in all Baccharis species. This constituent in isolation, as well as the EOs of B. calvescens, B. mesoneura, and B. oblongifolia, caused mortality in over 80% of adults of D. suzukii at a discriminatory concentration of 80 mg L−1 in bioassays of ingestion and topical application. These results are similar to the effect of spinosyn-based synthetic insecticides (spinetoram 75 mg L−1) 120 h after exposure. Limonene and EOs from all species had the lowest LC50 and LC90 values relative to spinosyn and azadirachtin (12 g L−1) in both bioassays. However, they showed the same time toxicity over time as spinetoram when applied to adults of D. suzukii (LT50 ranging from 4.6 to 8.7 h) in a topical application bioassay. In olfactometry tests, 92% of D. suzukii females showed repellent behavior when exposed to the EOs and limonene. Likewise, the EOs of B. calvescens, B. mesoneura, and B. oblongifolia significantly reduced the number of eggs in artificial fruits (≅ 7.6 eggs fruit−1), differing from the control treatment with water (17.2 eggs fruit−1) and acetone (17.6 eggs fruit−1). According to histological analyses, the L3 larvae of D. suzukii had morphological and physiological alterations and deformations after exposure to treatments containing EOs and limonene, which resulted in high larval, pupal, and adult mortality. In view of the results, Baccharis EOs and their isolated constituent, limonene, proved to be promising alternatives for developing bioinsecticides to manage of D. suzukii.
Aphids are among the major pests associated with strawberries in Southern Brasil. In this study, we identified the main species that occur in strawberry fields in the states of Paraná and Rio Grande do Sul, Brasil. We also compared the effectiveness of different sampling methods and studied the population dynamics of aphid species during two strawberry crop cycles in the municipality of Pinhais, state of Paraná, Brasil. Chaetosiphon fragaefolii (Cockerell) and Aphis forbesi Weed were the main species associated with strawberry. The method of hit plant and the Möericke trap showed equal effectiveness to capture wingless and winged insects. The peak population of aphids in the state of Paraná occurred from September to November. This information can help producers to implement strategies to monitor and control the major aphid species that occur in strawberry culture.
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