IRRADIATION OF VEGETABLES UNDER CONDITIONS OF CLOSED GROUND WITH LIGHT SOURCES WITH EMITTING ADDITIVES

Abstract

Purpose. The paper considers peculiarities of using artificial illumination sources with effective spectral composition of radiation for conditions of closed soil. Methodology. High-intensity sodium lamps (DNaT400), high- intensity sources with composition of sodium amalgam with cesium additives were investigated (Hg-20%, Na-7 5%, Cs-5%), potassium (Hg-20%, Na-79%, K-1%). Results. As a result of experiments, it was determined that the spectral radiation composition of lamps with additives Cs, K, Rb has a lower radiation intensity compared to standard high pressure sodium lamps (DNaT) in the region of 500-600 nm and significantly higher intensity in red (600-700 nm) and near infrared regions. The physicochemical properties of the sodium-cesium-mercury system have been studied. Melting points of ternary alloys, thermodynamic properties of melts of ternary system Na-Cs-Hg and double system of Na-Hg system are determined. The parameters of batch pressures of component vapors are calculated. The composition of the discharge tube amalgam is selected, in which the ratio of sodium and mercury concentrations is close to the corresponding ratio in a standard sodium lamp, and cesium additives vary in the range from 5 to 10 atm. %. The influence of cesium content in amalgams on light and color parameters of lamps is considered. Tomatoes were used in the experiment, which were additionally illuminated with lamps DNaT400, high intensity discharge tube filled light sources (20at.% Hg, 77at.% Na, 3at.% Cs20); (20at.% Hg, 75at.% Na, 5at. % Cs); (20 at. % Hg, 73 at. % Na, 7 at. % Cs); (20 at. % Hg, 70 at. % Na, 10 at. % Cs). Originality. In the use of high-pressure sodium lamps with a filling of the discharge tube in different weight ratios of Hg, Na, Cs. Practical value. When using high-intensity light sources with additives Cs having amalgam composition (20 at.% Hg, 75 at.% Na, 5 at.% Cs), growing tomato plants in the early stages of development is most effective. The total content of chlorophyll in tomatoes when irradiated with a high- pressure sodium lamp with cesium additives is 1.4 ÷ 2.5 times higher than when irradiated. DNaT400.