An apparatus for subcortical injection of a substance into a plant which comprises: • a body; • a substantially rectilinear needle pierced at its center by a channel opening out through at least one hole on the side wall of the needle and therefore not at the end thereof intended to penetrate the plant; • a reservoir communicating with the needle and containing the substance to be injected; • a first actuator capable of moving the needle along the axis of the needle and in a centrifugal direction so as to allow it to be inserted into the plant; • a second actuator capable of compressing the volume of substance in the reservoir so as to allow this substance to be injected through the needle to the plant via the channel; characterized in that it further comprises: • a first force sensor associated with the body, which allows the bearing force of the apparatus on the plant to be measured; • a second force sensor associated with the first actuator, which allows the force of insertion of the needle into the plant to be measured following the mobilization thereof by the first actuator; • a third force sensor, which allows the pressurization force of the volume of substance in the reservoir to be measured; and • at least one microcontroller: 1- which allows the activation of the first actuator only if the first force sensor detects a bearing force; 2- which then modulates the activation of the first actuator, and therefore the injection of the needle into the plant, depending on the insertion force measured by the second force sensor and, simultaneously with or after the insertion has been carried out; 3- which modulates the compression of the volume of substance in the reservoir, and therefore the injection of this substance into the plant, depending on the force measured by the third force sensor. • a body; • a substantially rectilinear needle pierced at its center by a channel opening out through at least one hole on the side wall of the needle and therefore not at the end thereof intended to penetrate the plant; • a reservoir communicating with the needle and containing the substance to be injected; • a first actuator capable of moving the needle along the axis of the needle and in a centrifugal direction so as to allow it to be inserted into the plant; • a second actuator capable of compressing the volume of substance in the reservoir so as to allow this substance to be injected through the needle to the plant via the channel; • a first force sensor associated with the body, which allows the bearing force of the apparatus on the plant to be measured; • a second force sensor associated with the first actuator, which allows the force of insertion of the needle into the plant to be measured following the mobilization thereof by the first actuator; • a third force sensor, which allows the pressurization force of the volume of substance in the reservoir to be measured; and • at least one microcontroller: 1- which allows the activation of the first actuator only if the first force sensor detects a bearing force; 2- which then modulates the activation of the first actuator, and therefore the injection of the needle into the plant, depending on the insertion force measured by the second force sensor and, simultaneously with or after the insertion has been carried out; 3- which modulates the compression of the volume of substance in the reservoir, and therefore the injection of this substance into the plant, depending on the force measured by the third force sensor. 1- which allows the activation of the first actuator only if the first force sensor detects a bearing force; 2- which then modulates the activation of the first actuator, and therefore the injection of the needle into the plant, depending on the insertion force measured by the second force sensor and, simultaneously with or after the insertion has been carried out; 3- which modulates the compression of the volume of substance in the reservoir, and therefore the injection of this substance into the plant, depending on the force measured by the third force sensor.