Anionic relationships in leaf petiole sap of tomato and capsicum plants growing in a glasshouse

The nitrate, chloride and sulphate content and their interaction effects in capsicum and tomato plants growing in glasshouse under fertigation systems was studied. Using leaf petiolesap concentrations as an index of the uptake rhythm, it was found that nitrate‐chloride and nitrate‐chloride plus sulphate relationships are regulated by potential or logarithmical laws. Nitrate‐sulphate interactions only appear clear in capsicum plants, but not for tomato.

The utilization of these interaction curves may permit the use of waters with a relatively high saline level for the irrigation of the both capsicum and tomato plants, by suitable planning of the nitrate supply in the fertigation program.