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Distribution of CO2 concentrations in tomato cultivation with the microprocessor EUDW-2 system

Włodzimierz Starzecki*, Andrzej Libik**

**The Franciszek Górski Department of Plant Physiology
**Polish Academy of Sciences
**Sławkowska 17, 31-016 Cracow, Poland
**Department of Vegetable Crops
**Faculty of Horticulture, Agricultural University
**29 Listopada 54, 31-425 Cracow, Poland

The distribution of CO2 concentration was investigated in a developed (about 80-day old) greenhouse tomato stand. The pulsatory supply of 100% CO2 at time intervals of 30s/210s was controlled by a prototype EUDW-2 monitoring system. The period in which the concentration gradually reached the programmed level of 800 μmol(CO2) mol-1(air) was used to obtain the greatest efficiency of the system (21 RtE). At the level of 50 and 100 cm wavy changes in CO2 concentration of the amplitude of 714 and 105 μmol(CO2) mol-1(air), respectively, were observed. The undulatory character gradually disappeared with increasing altitude and at 150 cm increases were already directly proportional, reaching 39 μmol(CO2) mol-1(air) towards the end of the 240s work cycle of the EUDW-2 system. On the other hand, mean increases in CO2 concentrations DX reffered to the entire work cycle of the system were DX50=193, DX100=75, and DX150=19 μmol(CO2) mol-1(air) at the successive levels. When the programmed CO2 concentration was reached, the monitoring system passed on to an economic work mode expressed by a free-four-fold reduction of time of the gas inflow in the successive work cycles of the system. With the reduced gas inflow the transgressions of CO2 concentration were less pronounced in the lower zone, amounting to 60-50 μmol(CO2) mol-1(air), and the wavy character of changes in CO2 concentration more rapidly disappeared.

Starzecki W., Libik A., 1999. Distribution of CO2 concentations in tomato cultivation with the microprocessor EUDW-2 system. Folia Horticulturae 11/1: 3-13.