In this publication, comparisons are made between the results of crop analyses obtained with the aid of dried material and plant sap. The crop samples used for the analyses were collected from experiments in which crops were grown in nutrient solutions with varying nutrient element contents. The experimental crops consisted of tomatoes, cucumbers, eggplants and lettuce. Of the first three crops, the leaf petioles and leaf laminae were used as samples and in the case of lettuce, midrib parts and leaf edges were sampled.