The effect of different LED light spectrums on rooting and growth of benjamin fig cuttings

Sunlight is the only source of natural energy for the growth of plants. Natural light is a cost- effective source for commercial agricultural production for economic reasons. But according to the environmental conditions, artificial light can also be used for cultivation of plants. One of the important horticultural activities is vegetative propagation of plants by rooting of cuttings. Due to the short length of cuttings and the economic nature of propagation throughout the year, it is possible to use multi-tier growth chambers in which optimal conditions are provided for rooting. One of the widely used indoor ornamental plants is Benjamin fig, whose commercial propagation method is by rooting of cuttings. In order to optimize the light conditions necessary for the rooting and growth of Ficus benjamina 'Starlight' cuttings, the effect of different LED light spectrums (red, blue, red + blue and white) on root regeneration and growth of its cuttings was studied. Three months after planting, rooting percentage, rooting index and morphological indices were measured. The results showed that except for the root length trait which was the longest (16.8 cm) in the combined light of red + blue LED, the highest number of root branches (12), root fresh weight (1.42 g), Root dry weight (0.36 g) and root volume (2.8 cm3) were related to white light. In terms of shoot growth indices, the highest leaf area (10.9 cm2) and shoot fresh weight (4.82 g) were observed in white light and the highest shoot dry weight (1.4 g), shoot length (23.2 cm) and shoot number (3/6) were observed in blue + red light. The highest rooting percentage (100%) was observed under red light and the highest rooting index (4.5) was related to blue LED light. Based on the results of this experiment, the white light spectrum has a better effect on the root growth of the cuttings, and for the growth of the aerial parts of the cuttings, the combined red + blue light has a better effect than the blue and red monochromic LEDs. In general, white LED light is recommended to produce rooted Benjamin fig cuttings with good quality.