ABSTRACT

The European pepper moth, Duponchelia fovealis (Lepidoptera: Crambidae), is a key pest in strawberry production. Entomopathogenic fungi (EF) and parasitoids of the Trichogrammatidae family are effective biological control agents of this pest with the potential to be used jointly for improved efficacy. This study aims to evaluate the susceptibility of Trichogramma atopovirilia and Trichogramma pretiosum to two Beauveria bassiana strains (B2 and B3) and two commercial bioinsecticides (Bovemax® and Methamax®) by applying them to D. fovealis eggs in pre- and post-parasitism periods. Pre-parasitism application of B2 and B3 did not affect the percentage of D. fovealis eggs parasitized by either Trichogramma species, except in the case of T. atopovirilia when eggs were sprayed with B3 at 1.5 × 105 conidia mL−1 (16.7% less than the control). In contrast, eggs sprayed with 1.5 × 108 conidia mL−1 of the commercial bioinsecticides were not parasitized by any Trichogramma species. Overall, the EF tested reduced the parasitism rate, adult emergence, and longevity of Trichogramma adults by less than 30% in all cases. The adverse effects of the B. bassiana strains and commercial products on the biological traits of both Trichogramma species were minimal, meaning that these agents can be used jointly in D. fovealis control strategies.

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.

Maintaining plants in the field for two consecutive crop cycles is one of the latest techniques used by strawberry growers to reduce production costs. The goal of this research was to evaluate the postharvest fruit quality of six strawberry cultivars produced for two consecutive seasons with the same plants. They were planted from May to July 2010 under low-tunnel and fruits were evaluated in two growing seasons (season 1= January, February, and March 2011 and season 2= August, September, and October 2011), totaling three harvests of each cultivar in each year season. Fruits were picked up randomly among 500 plants of each cultivar, organized into five replications of five fruits and kept for three days before analysis under refrigeration (average temperature of 4°C). Variables analyzed were: soluble solids content, titratable acidity, soluble solids content/titratable acidity, flesh firmness, C vitamin content, sensory characteristics (sweetness, flavor, acidity, aroma, shape and flesh firmness), and mineral composition (Ca, Fe, K, Mg, Mn, Cu and Zn). 'Albion', 'Monterey' and 'San Andreas' showed good physical, chemical and sensory characteristics in both seasons. In general, fruits produced during the season 1 showed better physical, chemical and sensory characteristics than fruits produced in season 2. 'Palomar' and 'Portola' were better than the other cultivars concerning C vitamin content in both seasons. 'Palomar' showed higher potassium, calcium, magnesium, manganese and zinc levels, and 'Portola' showed higher calcium and iron levels.

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