Influence of the photosynthetic photon flux density value on microclimate in healing and acclimatization tunnels for vegetable seedlings

Abstract

For seedlings production, healing and acclimatization are the most important processes in obtaining healthy and vigorous plants. Influence of photosynthetic photon flux density (PPFD) on a healing tunnel environmental parameters was investigated. The experiments were carried out at HORTING institute’s micro-production greenhouse using 9 alveolar trays with 104 eggplant seedlings each, placed in two sections of the specialized tunnels for healing and acclimatization of seedlings. In each section and in the research greenhouse was measured the levels of photosynthetic photon flux density, of temperature, of the relative humidity and the level of CO2 concentration. From the meteorological station of the HORTING institute, data on the variation of outdoor temperature, relative humidity and light intensity were downloaded. The variation of the micro-climate factors in the two sections according to their external environmental conditions were compared. One of the conclusions is that seedlings that have benefited from an additional artificial source of light have a more intense photosynthetic activity. The difference on CO2 concentration in the two sections over the same time period lead to this conclusion. This gives the certainty of obtaining healthy and vigorous plants in the sections with supplementary lighting.