Using Nitrate-N Petiole Sap-Testing for Better Nitrogen Management in Vegetable Crops

Vegetables have a relatively high nitrogen requirement and at times growers apply too much fertilizer-N that contributes to ground and surface water pollution. Fertilization can be made more efficient by plant analysis. Plant tissue (petiole) nitrate testing is a way of monitoring the nitrogen condition of the crop during the growing season. This is an especially useful method as the petiole is a very good indicator of current N supply and management practices such as fertigation allow for corrective measures when deficiencies are found.