Benefícios da associação com Glomus clarum e adubação fosfatada em cultivares crioulas de milho, RS

Abstract

Maize has great economical importance, while Brazil is the third largest producer, but does not stand out among the countries with the highest level of productivity, due to the large number of small producers who cultivate this cereal with low or no technological level. In this sense, given the importance of maize in the national scene, action research must be performed with maize cultivars used by small producers, especially cultivars of maize landraces, which have not gone through the process of genetic improvement in research institutions. Thus, there is a need to study the Land varieties of corn, about the efficiency in the development and establishment of colonization symbiotic mycorrhizal fungi, as this improves absorption of nutrients, and tolerance to abiotic stresses by the plant in order to minimize costs production mainly related to the use of phosphate fertilizers. The objective of this study was to evaluate the influence of phosphorus and mycorrhizal inoculation on initial Land varieties of corn, preserved by the Association of Seed Guardians Creole, the city of Ibarama, located in the Central Sierra, Rio Grande do Sul. The experiment was performed in a factorial 8x4x2, eight cultivars of maize landraces (Amarelão, Brancão, Cabo Roxo, Cateto Amarelo, Colorido, Cunha, Ferro and Palha Roxa), four phosphate 0 (control), 50 , 100 and 200 mg.kg-1 soil and a species of arbuscular mycorrhizal fungus (Glomus clarum Nicol. & Schenck) and treatment without inoculation, which evaluated the percentage of mycorrhizal colonization, shoot dry matter and plant height . The experiment was conducted in a greenhouse at the Federal University of Santa Maria and the data were subjected to analysis of variance, mean Scott Knott test (at 5% probability of error) and regression analysis. The results showed that significant difference occurs for percentage of mycorrhizal colonization in cultivars Brancão, Cabo Roxo, Cateto Amarelo, Colorido, Ferro and Palha Roxa, due to different levels of phosphorus in the soil, which does not occur in cultivars and Amarelão Cunha and also that the use of Glomus clarum inoculated into maize was effective in increasing dry matter of shoots and plant height in doses of phosphorus that stimulate mycorrhizal colonization.