Influence of the spectral composition of light on the morphogenesis of the epiphytic orchid Cattleya labiata Lindl. cultivated in the greenhouse

Abstract

This work evaluates the test results of 3 types of LED lamps with different spectral composition of radiation and photon flux of photosynthesis (PPF, μmol/m2/sec): PPG T8I Agro (37), Navigator DSP-FITO (47.5) and DDP06-3×8-004 UHL 4 ‘Home Farm' (100), in the greenhouse culture of the orchid Cattleya labiata Lindl. The parameters of the thickness of annual leaves, the percentage of dry matter and the increase in biomass per unit of leaf surface (μg/cm2) formed over a period of 140 days were used as indicators to assess the degree of influence of the spectral composition of light on the morphogenesis of C. labiata plants. The spectral characteristics of the LED lamp DDP06-3×8-004 UHL 4 ‘Home Farm' with a white glow, intensity PPF 100 are considered as the most favorable for the successful greenhouse cultivation of the orchid Cattleya labiata Lindl. The combination in its spectrum of red and green spectra with their ratio equal to 1.3, and when the ratio of red and blue spectra equal to 3.34, a higher level of dry matter accumulation is observed per unit of leaf surface area white maintaining parameter of the leaf structure characteristic of a given plant species.