The dynamics and correlation between nitrogen, phosphorus, potassium and calcium in a hazelnut fruit during its development

The dynamics and correlation between nitrogen, phosphorus, potassium and calcium were studied during the fruit development of three crossbreeds of hazelnut. The results showed that the young fruit rapid growth stage and kernel development stage were the critical periods for the absorption and accumulation of these mineral elements.With three crossbreeds, the content of nitrogen followed such a pattern that decreased in the initial stage, remained constantly in the middle stage and increased markedly in the late stage; phosphorus followed a slightly different pattern where it decreased in the initial stage, also remained constant in the middle stage, and first increased rapidly and then decreased rapidly in the late stage; potassium followed the pattern where it decreased mildly in the initial stage, increased gradually in the middle and late stages; calcium followed the pattern where it decreased sharply in the initial stage, remained constant in the middle and late stages. Nitrogen, phosphorus and potassium in fruits showed a significant or very significant positive correlation in the development course of hazelnut fruit and there was a dynamic equilibrium of coordination among the three elements.