Micronutrients Changes during the growing season in different dryness classes of Brant`s oak (Quercus brantii Lindl.) trees, Chaharmahal and Bakhtiari Province

The phenomenon of oak decline is one of the most important current problems in the Zagros forests. Lack of nutrients and differences in nutrient uptake between healthy Brant`s oak (Quercus brantii Lindl.) and trees affected by decline is one of the main causes of dryness of these trees. Tree nutrition can be considered as a management strategy to solve this problem and stop the decay of oak trees. Nutrient spraying is one of the common methods of plant nutrition that meets the needs of the plant in a short time. In this research, the similar trees of two forms (coppice and seed-origin) were selected in the Monj area of Chaharmahal and Bakhtiari province. In each form, trees were divided into three levels of health (Healthy, dieback and crown drought up to 50%). Five similar trees by dimension were selected in each level of health (totally 30 trees). Before and after nutrient spraying, the quality characteristics of the trees were recorded and a mixed sample of leaves was prepared from them. Nutrient spraying were done at full time of leaves from early June to July with an interval of 10 days in three shifts. The results showed that the amount of micronutrients elements in the leaves of trees at the beginning of the growing season was significantly higher than the end of the season. Among the micronutrients elements, the amount of boron in the leaves of healthy trees was more than decaying trees. Qualitative evaluation of trees showed that the progression of dieback has stopped in most of the studied trees. Feeding of decaying trees and increasing the possibility of nutrient uptake from the soil can be effective in stopping the decay of trees.