Produção e teor de nitrato em alface cultivada sob malhas de sombreamento e aplicação de Calcareacarbonica em solos provenientes de sistema orgânico e convencional

• Ano de defesa: 2016
• Autor(a) principal: Cezar, Arthur de Canini
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Departamento de Agronomia; Programa de Pós-Graduação em Agroecologia; UEM; Maringá, PR; Centro de Ciências Agrárias
• Palavras-chave em Português: Produção orgânica; Qualidade de luz; Agricultura familiar; Horticultura; Brasil.; Organic production; Quality of light; Family agriculture; Horticulture; Brazil.; Ciências Agrárias; Agronomia
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/1085

Organicfarminghasgrown by leaps and bounds on thelastdecade. However, despite the presented evolution, theorganicproduction system lacksscientificstudiesthatsupportmany empirical results.In theorganic system it is common to use differenttypes of nets withthepromise of increasedproductivity and otheradvantages, in particular for theproduction of oleraceous.Despite its use, few scientific studies assess theeffectiveness of these nets oncropyields and quality. Furthermore, it hasnothingpublishedcomparingtheeffect of these nets withdifferentproduction systems (organic and conventional systems) and the use of homeopathicremedies. Therefore, thisworkaimstostudythe production and nitrate content in lettucegrownunderdifferent nets, soils from organic production system with organic fertilizer (organic treatment) and soils from conventional system with chemical fertilizer (conventional treatment), treatedornotwithhomeopathyCalcareacarbonica(12 and 30 CH).The experiment was conducted in a greenhouse and lettuceplants were cultivate underdifferent colornets (red, black, thermo reflective) and without cover. Withineach cover the plants were grown in organic or conventional treatment. After 52 days of transplantation, lettuces were harvested and weighed to obtain fresh weight. With the aid of a spectroradiometer, reflectance, transmittance, absorbance and irradiance of each net were analyzed, demonstrating different behaviors for these variables.The homeopathies have led to reduction on fresh weight when using the black net combined with the conventional treatment (30 CH), red net with organic treatment (12 and 30 CH) and without cover in the organic treatment (12 CH).In general, thered net hadthebest performance whencomparedwiththeother nets, especially in theconventional treatment. However, without cover was theconditionwhichprovidedhigher accumulation of freshbiomasswhencomparedtothoseobtainedwiththeothers nets. In both soils tested, thepresence of homeopathyseemstohavechangedthe nets behavior/efficiency. Conventional treatment, whenconductedunderblack net, redorwithout net showedhigherlettuce productivity, regardless of homeopathy. The thermo reflective net ledtolowerproductivitywith no differencesbetween organic and conventional treatment and homeopathicremedies used in the presented study.Despite the productivitysuperiority related to the conventional treatment, the data demonstrated that plants under this treatment had significantly higher nitrate accumulation comparing with the organic treatment, demonstrating poor quality of the same. Plants grown under colornets also showed nitrate values higher than those developed without cover, demonstrating strong influence of light on this variable. The homeopathies showed different results,C. carbonica 30CH led pathogenesis on plants when under the red and thermo reflective nets, in the conventional treatment, resulting on higher nitrate accumulation. Under the black net, both homeopathies reduced the effects of low luminosity, reducing the nitrate concentration in the conventional treatment.