Resumo

LIMON ORTEGA, Agustin; PELAEZ CRUZ, Deyxi; LEYVA MIR, Gerardo  e  ESPINOSA BARRETO, Catalina. Effect of the dose of N in the incidence of Fusarium spp. in wheat roots under permanent beds. Rev. Mex. Cienc. Agríc [online]. 2016, vol.7, n.5, pp.1155-1165. ISSN 2007-0934.

The application of conservation tillage systems like permanent beds has important advantages over the production of crops. However, crop residues are left on the ground promote disease development. In this study the incidence of fungi in the root of wheat was evaluated with four doses of N (0, 20, 40 and 60 kg ha-1) in rotation with maize in three doses of N (0, 60 and 120 kg ha-1) under permanent beds. The identification was made by direct microscopic observation was found seven species of Fusarium and Helminthosporium three. The incidence of most of these were affected by the application of N. The incidence of Fusarium moniliforme was negatively related to performance spikes per m2 and total absorption of N. The reduction rate (slope) of each of these parameters and their effect low incidence (intercept) dose dependent N. The effect of these parameters on the incidence was lower for the application of 40 kg N ha-1 to 60 kg N ha1. The rest of the identified species did not show a definite pattern. Moreover, the differential normalized vegetation index (NDVI) collected in treatments with the application of 60 kg N ha-1 in three stages of development presented a negative association with the incidence of Fusarium moniliforme. These results indicate the importance of proper application of N to reduce the effect of impact on plants. The NDVI readings proved to be a potential tool for indirect detection of disease at the root.

Palavras-chave : nitrogen; NDVI; permanent beds; root diseases; wheat.