Effects of fertilizer rates and dates of application on apricot (cv Bergeron) cropping and pitburn

Various nitrogen (N) and potassium (K) fertilizer rates and dates of application were assessed in an apricot orchard. High N fertilization enhanced vegetative growth, yield and average fruit weight and aggravated fruit pitburn incidence. Increasing K fertilization enhanced fruit soluble solids and colouring, but did not affect pitburn. Pre-harvest versus post-harvest applications of fertilizers did not influence vegetative growth, yield or average fruit weight, but tended to reduce fruit soluble solids and colouring. At all times of evaluation of pitburn, there was a positive correlation between fruit N content and pitburn incidence. Furthermore, for a given fruit N content, pitburn appeared to increase with the duration of conservation. A high fruit N content has to be considered as a main predisposing factor for pitburn in apricot. A negative correlation between pitburn incidence and fruit Ca content also was detected a week after harvest. [Copyright &y& Elsevier]