RATES OF NITROGEN AND SOURCES OF SUPLEMENTAR Cu AND Mn ON THE SEVERITY OF THE RUST AND MORPHOLOGIC ATTRIBUTES OF MAIZE

• Main Authors: DURVAL DOURADO NETO, ANDRÉ RODRIGUES DOS REIS, THOMAS NEWTON MARTIN, JOSÉ LAÉRCIO FAVARIN, ANTONIO LUIZ FANCELLI, ANDRÉ LUÍS TOMAZELA
• Format: Article
• Language: English
• Published: Associação Brasileira de Milho e Sorgo 2006-08-01
• Series: Revista Brasileira de Milho e Sorgo
• Subjects: Zea mays L.; Physopella zeae; manganese sulphate; manganese chelate; copper hidroxide; copper sulphate
• Online Access: http://rbms.cnpms.embrapa.br/index.php/ojs/article/view/182/179
• ISSN: 1676-689X; 1980-6477

The application of high rates of nitrogen increases the risk of disease in the maize culture, while copper and manganese can reduce the occurrence of the same ones because these nutrients participate in the plant’s defense mechanism. This work was carried out with the objective of evaluating the influence of rates of nitrogen and sources of supplementary copper and manganese, applied foliarly, on the severity of the tropical rust (Physopella zeae) and morphologic attributes, as well as the viability to substitute the use of fungicide for the micronutrients in the control of this disease in maize culture. The experiment consisted of nine treatments with four repetitions, where the severity of the Physopella zeae, the height of plants, steam diameter, leaf area index, total dry matter, length of spike, number of rows of grains, grains for row, mass of 100 grain, and production of grains were evaluated. The supply of 200 kg ha-1 of N increased the maize production and the severity of the tropical rust (Physopella zeae), regardless of the sources of copper and manganese applied in leaves. The copper sulphate was more efficient in the suppression of the tropical rust (Physopella zeae) than copper hidroxide. The suplementar foliar of Cu and Mn applied in this experiment does not substitute the fungicide in the control of the tropical rust.