Abstract

An increase of soil salinization risk associated to a detriment of water input (precipitation and irrigation water) on agriculture opens an opportunity to enhance lycopene concentration of tomato fruit. The objective of this experiment was to evaluate the impact of the application of fulvic acid (FA) on apparent soil electric conductivity (ECa) and fruit lycopene concentration of tomato plants receiving terminal drought stress. The trial was conducted at Los Tilos Experimental Center of INIA La Platina (Buin, Región Metropolitana Santiago, Chile) during season 2020/21. Pomodora tomato plants (‘Plum Regal’) were transplanted in the field following a split plot in a randomized complete block design with (F1) and without (F0) fulvic acid applied to the soil. A terminal drought stress treatment was imposed lasting 15 days before harvest (T1), equivalent to 50% of the irrigation water, while a control treatment received full irrigation reposition (T0). Total water applied, ECa at several points of the soil wetted profile, yield and lycopene concentration in the fresh fruit were measured. Terminal drought irrigated plots without fulvic acids (T1F0) showed an increased ECa, averaging 0.24 dS m-1 in the profile, equivalent to 2.60 dS m-1 of EC of saturated paste extract. While yield was not affected by the treatments, lycopene concentration on the fresh fruit showed an interaction response of both FA and irrigation factor, reaching a maximum of 69.0 mg kg-1 on plants irrigated with a terminal drought stress without the application of FA (T1F0). Although the application of FA did not increase the fruit lycopene concentration, it contributed to decrease the ECa of profile opening an opportunity to cultivate soils with saline restrictions.