The lighting system 9 for plant cultivation according to the present invention includes an intermittent illumination mode in which a light source emits light in an illumination cycle in which a light period width that is turned on for a predetermined time period and a dark period width that is turned off for a predetermined time period are one cycle. It is possible to switch between continuous illumination modes in which the light source emits light. The lighting system 9 for plant cultivation according to the present invention includes a light source 3, a light source driving unit 2 that drives the light source 3, and a control unit 1 that transmits a pulse signal to the light source driving unit 2. The first pulse generator 11 for generating the first pulse signal S1 having a predetermined frequency, the second pulse generator 12 for generating the second pulse signal S2 having a frequency different from the predetermined frequency, and the first pulse signal S1 And a pulse signal selection unit 13 that selects one of the second pulse signal S2 and transmits the selected pulse signal S2 to the light source driving unit 2, and the frequency of the pulse signal received by the light source driving unit 3 from the control unit 1 is the first. When receiving the first pulse signal S1 from the frequency determination unit 21 for determining which frequency of the pulse signal S1 and the second pulse signal S2 and the control unit 1, the first pulse signal S1 is converted to a constant current output. Convert light The first drive unit 23 that drives 3 and the second drive unit 24 that drives the light source 3 by outputting a pulse with the same pulse waveform as the second pulse signal S2 when the second pulse signal S2 is received from the control unit 1. , 25.本発明に係る植物栽培用照明システム９は、所定時間点灯する明期幅と、所定時間消灯する暗期幅とを一周期とする照明サイクルで光源が光を照射する間欠照明モードと、連続的に光源が光を照射する連続照明モードとを切り替え可能に構成される。また、本発明に係る植物栽培用照明システム９は、光源３と、光源３を駆動する光源駆動部２と、光源駆動部２にパルス信号を伝送する制御部１とを備え、制御部１が、所定の周波数の第１パルス信号Ｓ１を発生させる
