On the left top row are potassium deficient cucumbers. The stem end is bottle-necked. The second row shows nitrogen deficiency. The stem end is fully round and the blossom end tapers. The bottom cucumber has been fertilized with NPK fertilizer. Both ends have plenty of nitrogen (N), and potassium (K). But it is rotting, even though freshly picked, because the nitrogen has lowered the mineral content. This cucumber came from a garden where chemical fertilizers were used. The top two rows are organic, from soils that are potassium and nitrogen deficient.

The cucumbers in the bowl here have plenty of nitrogen and potassium.