Fundamentals of developing a cultivar-specific technology for radish (Raphanus sativus L.) production under intensive photoculture conditions

Abstract

Intensive light culture of plants has become firmly established in practice and is used for year-round production of highquality plant products. Research into plant responses to specific conditions at the genotype-environment level is essential for developing optimised, adaptive technologies for growing various species and varieties under light culture. The objective of this research was to develop the foundations of a varietal technology for radish ( Raphanus sativus L.) production. The Peterburgskij fioletovyj radish variety was studied under intensive light culture conditions in a series of experiments at varying seeding densities (200 and 300 plants/m 2 ), harvest times (25-35 days from sowing), photoperiod durations (12 and 16 hours), and spectral composition of the light environment. The light sources were DNaZ-400 lamps and three original full-spectrum LED luminaires simulating natural light at different times of day: AFI-3000 with R:B (red:blue light) = 4.3:1 (the sun is close to the horizon), AFI-4000 with R:B = 2:1 (morning and afternoon light), and AFI-5000 with R:B = 1.2:1 (midday sunlight). The conditions closest to optimal for producing high yields of commercial radish root crops (up to 50 kg/m 2 per year) were achieved with a seeding density of 200 plants/m 2 , harvesting 25-30 days after sowing, both studied photoperiods (12 and 16 hours), and a light environment created by the AFI-5000 luminaire with the highest content of blue wavelengths in the spectrum.