Effects of foliar urea application on lulo (Solanum quitoense cv. septentrionale) plants grown under different waterlogging and nitrogen conditions

•Lulo plants are susceptible to waterlogging conditions.•An optimum nitrogen status enhanced plant tolerance to waterlogging periods.•Foliar nitrogen sprays helped to ameliorate the effects of waterlogging.

Lulo is an Andean fruit commonly cultivated in Colombia where it is common to find prolonged waterlogging periods due to the rainfall. An experiment involving lulo plants grown under two N fertilization levels (10 and 110 mg N L H2O−1) was conducted under greenhouse conditions. Plants were subjected to three periods alternating between waterlogging and rest (S1–S3). In addition, a group of plants was treated with foliar urea applied at a concentration of 250 mg N L−1. Results showed that plants under high N level (110 mg N L−1) and subjected to waterlogging conditions had better performance than plants cultivated with low nitrogen (10 mg N L−1) under flooded periods, since shoot length, total plant dry weight, and leaf area were higher in plants with high N (33%, 80% and 75%, respectively) than in plants with low N. In general, waterlogging decreased stomatal conductance (gs), transpiration and leaf water status, and increased stem diameter and leaf tissue density. Foliar N applications increased photochemical efficiency and chlorophyll concentration, as well as leaf water content under flooded conditions. In conclusion, this study found that lulo is a species susceptible to waterlogging conditions and the negative impact of this abiotic stress can be mitigated by the positive effects of foliar N sprays, since these ones can improve plant acclimation.