The Physiological Response of Lulo Plants (Solatium quitoense var. septentrionale) to Soil and Foliar Applications of Nutrients

摘要

The effects of nutrient deficiency on shoot length and physiological behavior of lulo plants grown under greenhouse conditions were evaluated. Four-month-old lulo fSolanum quitoense var. septentri-onalej 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 tosoil 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.