Seasonal Variation of Nutrients and Nutrient Rations in Apricot Leaves

The best method for determining the nutritional status of fruit orchards is leaf analysis. nutrient levels of plant tissues reflect the nutrient uptake of plants in the most accurate way. this study was conducted on 12 years old ismail ağa apricot cultivar grafted on “apricot seedling” rootstock at egirdir fruit research institute, isparta-turkey. in every couple of weeks as regular, leaf samples were collected at 15 different stages from starting full bloom to lasting until the end of the season. nutrient contents of leaf were determined and the seasonal changes of nutrients and the rations between nutrients were investigated. in leaves, n, p, cu, mn and zn showed a rapid decrease until mid-season. in the following periods, while n decreased and p increased slightly. cu, mn and zn remained stable until the end of the season. while ca increased until at the end of vegetation, k and b showed initially an increasing change until mid-season, subsequently a decreasing change. mg showed a rapid increase in the first 3 periods but decreased in the following periods. fe didn’t changed throughout the season. the rations of n:p, n:k, n:ca, n:mg, k:p, k:ca, k:mg, p:zn, ca:b, k:b in leaf were respectively and averagely 3.49-11.58, 0.49-1.97, 0.61-7.18, 3.96-12.94, 3.12-17.40, 1.07-3.64, 5.54-10.73, 80-523, 210-788, 687-989.