Organic products selectivity for Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) / Seletividade de produtos orgânicos para Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

The selectivity of different insecticides, fungicides and fertilizers used in organic soybean cropping was evaluated according to the protocols proposed by the Pesticides and Beneficial Organisms Working Group of the International Organization for Biological Control (IOBC) concerning adults and pupae of the egg parasitoid Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) under laboratory conditions. Treatments 1) baculovirus anticarsia 140 x 109 cpi; 2) Bacillus thuringiensis 16.8 g; 3) azadirachtin-A, azadirachtin-B, nimbina and salamina 9.6 ppm; 4) rotenoids 4% 4 L; 5) nitrogen 1.3%, phosphorus 3.0% and total organic carbon 8.0% 3 L; 6) sodium silicate 2% 4 L; 7) copper 7% + calcium 3.3% 1.8 L; 8) sulfur 20% + quicklime 10% 1.8 L were in general safe (class 1) to both adults and pupae of T. pretiosum . Differently, chlorpyrifos (control treatment) was harmful to this parasitoid. Therefore, the utilization of the tested natural derived products in the production of organic soybean is viable, without impairing the natural biological control allowed by T. pretiosum . Furthermore, both management techniques can indeed be used together in organic cropping aiming at reaching increasing or complementary control of target pests. Chlorpyrifos use, on the other hand, whenever possible, should be replaced by other products more compatible with biological control preservation.(AU)

A seletividade de diferentes inseticidas, fungicidas e fertilizantes usados no cultivo de soja orgânica foi avaliada de acordo com os protocolos propostos pela Pesticide and Beneficial Organisms Working Group of the International Organization for Biological Control (IOBC) sobre pupas e adultos de Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) em condições de laboratório. Os tratamentos 1) baculovírus anticarsia 140 x 109 cpi; 2) Bacillus thuringiensis 16,8 g; 3) azadirachtin-A, azadirachtin-B, nimbina e salamina 9,6 ppm; 4) rotenoides 4% 4 L; 5) nitrogênio 1,3%, fósforo 3,0% e carbono orgânico total 8,0% 3 L; 6) silicato de sódio 2% 4 L; 7) cobre 7% + cálcio 3,3% 1,8 L; 8) enxofre 20% + cal virgem 10% 1,8 L foram, no geral, inócuos (classe 1) para pupas e adultos de T. pretiosum . Diferentemente, clorpirifós (tratamento controle) foi nocivo para esse parasitoide. A utilização dos produtos de origem natural avaliados é viável na sojicultura orgânica sem impactar o controle biológico promovido por T. pretiosum . Ambas as táticas de manejo podem ser utilizadas conjuntamente na agricultura orgânica objetivando aumentar ou complementar o controle da praga-alvo. O uso do clorpirifós, por outro lado, sempre que possível, deve ser substituído por outros produtos mais compatíveis com a preservação do controle biológico.(AU)

Controle de plantas invasoras em cultivo orgânico e convencional de capim-limão (Cymbopogon citratus (DC) Stapf. ) / Weed control in organic and conventional crops of lemongrass

O cultivo orgânico é preconizado para o capim-limão (Cymbopogon citratus (DC) Stapf.) como planta medicinal promissora ao desenvolvimento de fármacos no Brasil. Objetivou-se avaliar técnicas de controle de plantas invasoras sobre componentes de produção de capim limão em cultivos orgânico e convencional. Dois experimentos foram instalados sob delineamento inteiramente casualizado, com quatro repetições, em esquema fatorial 2x2x3, considerando-se duas áreas (orgânico e convencional) e os tratamentos combinando cobertura morta (presente e ausente) e técnicas de controle de plantas invasoras (capina manual, roçada e nenhuma). Altura, perfilhamento, teor e rendimento total de óleo essencial de capim-limão no cultivo orgânico foram superiores ao convencional, mas a produtividade de biomassa aérea seca não diferiu entre ambos. A capina, com ou sem cobertura morta, favoreceu o rendimento de óleo no cultivo orgânico.

Organic farming is recommended for lemongrass as a promising medicinal plant for drug development in Brazil. The purpose of this paper was to evaluate the effect of the techniques to control weed on the plant height, tillering, biomass productivity, content and yield of the essential oil of lemon grass in organic and conventional crops. Two experiments were set in a completely randomized design with four replications, at a 2x2x3 factorial scheme, considering two areas (organic and conventional) and treatments combining mulching (present and absent) and weed control techniques (hoeing, skimming and none). Plant height, tillering, content and yield of the essential oil of lemongrass were better in the organic crop, but the biomass productivity did not differ between both areas. The biomass production was better in the conventional crop as to weed control, with or without mulching, and for organic crop under hoeing or skimming with mulching. Hoeing or skimming with no mulching improved the oil content in organic crops. Hoeing or skimming with mulching was better than any other weed control technique with no mulching, and hoeing was better than skimming, justifying its recommendation as a technique for this crop system.