Hiilidioksidilannoitus ja sen merkitys taimikasvatuksessa

Authors

• Irma Voipio Helsingin Yliopiston puutarhatieteen laitos, Viik

DOI: https://doi.org/10.23986/afsci.71648

Abstract

In the last few years the application of CO2 in greenhouses has become popular in Finland. Today about 15 % (19 ha) of all the heated greenhouses are equipped with propane burners for the enrichment of CO2. In this paper the factors which influence the CO2 content of the greenhouse as well as the airtightness of the greenhouse, the crop density, the growth substrate and the ventilation are discussed. These factors, beside the volume of the greenhouse, determine how much and at what time the CO2 is to be added. In the greenhouses where the observations were made, the CO2 was added by burning propane, and the CO2 content was measured using a Riken-Keiki gas indicator (figures 1 to 4). Experiments on growing young vegetable plants were carried out in growing chambers in 1963–65. When CO2 was added (0.2 %) the growth of the plants was accelerated. The acceleration was, however, closely dependent on the temperature, the day length and the time when the CO2 was added (only during day time or also during the night). Young cucumber plants grew best, using the CO2 enrichment, when the day temperature was 30–35° C and the night temperature 10—12° C and the day length 15 hours. In subsequent days with additional CO2, the growth of the cucumber plants was disturbed, the leaves became yellow and spotted. Young tomato plants developed best, when, using additional CO2, the temperature was 19° C and the day length 15 hours. Lettuce developed most rapidly in continuous light with enriched CO2, but lettuce, as well as celery, grew too much in length when the day temperature was 32–35° C. If the CO2 was added only in day time, the young plants were better than if it was given during 24 hours. The roots of the plants fed with additional CO2 developed vigorously and were well shaped compared to those grown without CO2 enrichment.