Nestor Valtir Panzenhagen

Aspectos técnico-ambientais da produção orgânica na região citrícola do Vale do Rio Caí, RS

Ha uma preocupacao crescente sobre a necessidade de producao e consumo de alimentos mais saudaveis, sem uso de agrotoxicos nem fertilizantes sintetico-industriais. Neste contexto se insere a pratica da agricultura orgânica, que, contudo, apresenta resultados ainda pouco avaliados nos meios academicos e cientificos. Assim, pretendeu-se nesta pesquisa diagnosticar aspectos tecnico-ambientais da producao orgânica na regiao citricola do Vale do Rio Cai, no Rio Grande do Sul. Inicialmente, foram selecionadas propriedades de oito agricultores familiares, todas ja convertidas ao sistema orgânico de producao, sendo aplicadas entrevistas semi-estruturadas. Os produtores mostram-se satisfeitos com o sistema orgânico de producao e revelam bom conhecimento sobre o ambiente, plantas, solos e processos agroecologicos, adquiridos atraves da participacao em eventos tecnicos e em reunioes da Cooperativa Ecocitrus. A constante troca de experiencias entre esses agricultores tem melhorado sua qualificacao tecnica, alem de melhor conscientiza-los nos aspectos politicos, economicos e sociais.

Controle químico do cancro cítrico em plantas jovens sob manejo convencional e orgânico

The objective of the present work was to evaluate the development of the citrus rootstock Poncirus trifoliata, severity of citrus canker, caused by Xanthomonas citri pv. citri and the control of this disease with copper sprays, in conventional and organic management systems, at the Centro de Formacao da EMATER, located in Montenegro, Rio Grande do Sul. Plants were artificially inoculated with the bacteria. To control citrus canker, different sources of copper as well as concentrations and number of sprays were tested. In the organic system the bordeaux mixture was applied while in the conventional system copper oxichloride was sprayed. Plants trunk diameter, dry matter of the rootstocks and number of canker lesions on leaves and branches were evaluated in both systems. Citrus canker incidence on the rootstocks was equally intense, and the seedlings development was similar in both systems, but the budded plants grew better at the conventional system. Copper treatments were not effective in controlling citrus canker at the rootstocks due the high inoculum concentration. On the budded plants, with low inoculum concentration, both the Bordeaux mixture and the copper oxichloride controlled the disease, and the better treatments were when 0.3% metallic copper was applied with interval of 14 days. To improve citrus canker control by Bordeaux mixture on organic systems, there is a need of efficient control strategies of the citrus leaf miner.