Narrow-spectrum light in combination with Phytosporin tulip bulbs pre-planting treatment effect on winter-spring tulips forcing quality

The aim of research is to study the effect of additional illumination with narrow-spectrum and white light from LED panels in combination with presowing treatment of bulbs with Fitosporin on the flowering time, flower quality and the duration of preservation of the decorative qualities of tulips during winter-spring forcing. Forcing tulips was carried out in central Russia (Moscow Region). The object of research is tulips of the Triumph class, Strong Gold variety. Additional lighting was carried out for six weeks, 8 hours daily (4 hours be-fore sunrise and 4 hours after sunset). The light period, taking into account additional lighting, is 16 hours. We measured the mass and length of the first leaf, the mass of the shoot, its length, and the length of the bud. After the end of the supplementary lighting, the generative shoots were cut according to the variants and placed in vessels with distilled water to study the preservation of decorative qualities. In combination with the pre-planting treatment of the bulbs with Fitosporin, the use of LED lamps gave a positive effect: the plants bloomed a week earlier than control, their biometric characteristics (weight, length of shoot and leaves, size and color of buds) were better, and cut generative shoots retained good decorative quality versus control (natural light). In the variant with additional illumination with narrow-spectrum light (70% red light, wavelength 630–660 nm and 30 % blue light, wavelength 440–460 nm) and preplant treatment with Fitosporin, the bud length was 21 % longer than in the control variant, and the mass of the leaf – by 16 %. The use of supplementary illumination of various spectral composition in combination with the pre-planting treatment with Fitosporin allows not only to accelerate flowering, but retains good decorative qualities of cut tulip flowers for 5–7 days, and also has a positive effect on the size and color intensity of the flower.