Field experiments (1990 and 1991) were carried out in Campinas, State of São Paulo, Brazil, during winter season, in order to study sprinkler irrigation and crop density effects on micrometeorological parameters (average air temperature and dew duration) and to evaluate their influence in the occurrence of spot blotch and powdery mildew in wheat crop. The results obtained were submitted to statistical analysis: comparison of means of two independent sample analysis (microclimate) and confidence interval analysis (infection rates). It was verified that in the most dense and irrigated plots the average air temperatures were lower (0.7°C) and the dew durations (DPM) were longer (45 minutes) than in the other plots. The infection rates of diseases were influenced positively by irrigation and crop density when the macroclimatic conditions were not favorable to disease development.
wheat; irrigation; crop density; microclimate and diseases