Chemistry in agriculture has been considered for several decades a formula synonymous with progress and development, as chemical engineering, mechanization, irrigation, modern agro-technical processes have contributed to a substantial increase in production. At present, the use of pesticides to increase agricultural productivity is considered to be a global hazard to the environment. This study examines changes in tree tolerance for major diseases and pests, disease and pest behavior, and the changes that occur in the recommended pesticide treatment. The researches were carried out on different species of fruit trees (apple, plum, and almond), cultivated in an intensive system, in five orchards located in Bihor county. The behavior of each species, as well as the behavior of different varieties with respect to tolerance to major diseases and pests, have been observed over the last 5 years (2013-2017). In addition, pesticide residues were monitored from all crops of apple, plum and almond. During 2015-2017, from March to May, the diseases were more virulent, requiring intensive intervention with systemic and contact fungicide combinations to achieve optimal efficiency; this fact has been correlated with the increase in the number of samples containing pesticide residues. This perspective allows an ecological remodeling of current progress in orchard development, including all aspects of environmental protection and the impact on population2 s health.
