The effects of nutrient deficiency on shoot length and physiological behavior of lulo plants grown under greenhouse conditions were evaluated. Four-month-old lulo (Solanum quitoense var. septentrionale) seedlings were transplanted into 2-L plastic pots containing peat as substrate. Treatments were established after the plants acclimatized for 14 days: (1) Control, without any type of fertilization, (2) fertilizer application to soil (with macro- and micronutrients), and (3) fertilizer application to soil plus foliar sprays containing nitrogen at a concentration of 125, 250, and 500 ppm N from urea. Lulo plants grown without any fertilizer were shorter and had lower plant height, dry mass, leaf chlorophyll content (SPAD readings), and Fv/Fm ratio than plants grown with fertilizer. Also, our results revealed that the lack of nutrients caused a greater amount of biomass in roots. Foliar sprays of urea did not have any positive effect on the evaluated variables. These results indicate that a poor nutritional status can be limiting the foliar uptake, causing a lack of response of lulo plants to foliar applications of N as a tool under nutritional stress conditions.