Effect of a Dynamic Climate on Energy Consumption and Production of Hibiscus rosa-sinensis L. in Greenhouses

Abstract

<jats:p>Production in a dynamic photosynthesis optimized climate (DC) was compared to production in a traditional and more stable climate (TC). Production of a tropical plant species (<jats:italic>Hibiscus rosa-sinensis</jats:italic> L.) in a DC resulted in between 18% and 63% reduction in energy use, mainly due to lower temperatures and increased use of thermal screens. In high light periods, the average day temperatures (ADT) were virtually the same in the different treatments, while in low light periods both ADT and average night temperature (ANT) were lower in the DC. Differential use of the screens resulted in a higher cumulative light integral in the DC. The number of lateral breaks was either the same or higher in the DC. Dry weight at the end of the production period was not significantly different in six of the seven experiments, and in five out of seven replications, plants grown in the DC were shorter than plants in the TC. Production periods between 10 days shorter and 21 days longer, for the DC compared to the TC, could not be explained by temperature integration alone. In the DC, a high positive DIF (difference between ADT and ANT) does not seem to increase elongation growth. The study illustrates that it is possible to produce a heat-demanding plant and save energy using a DC.</jats:p>

Seasonal variation of photosynthesis and photosynthetic efficiency in Phalaenopsis

“…During early spring, the greenhouse heated up mainly by irradiance leading to daytime temperatures up to 36°C, while at night ventilation with cool outdoor air allowed greenhouse air temperature to drop down to 24°C (Table 1). As a result, a positive DIF of 12°C could be obtained and saving energy is readily feasible according to Körner and Challa (2003), Lund et al (2006) and Körner and Van Straten (2008). In late autumn, however, low outdoor temperatures required supplementary greenhouse heating.…”

“…Growing ---Phalaenopsis therefore implies high heating expenses, especially in northern latitudes during winter. To reduce energy consumption, warm day/cool night temperature regimes have been proposed (Buwalda et al 2000, Lund et al 2006. However, taking into account that temperature is a main environmental factor influencing the metabolism and development of CAM plants (Lüttge 2004), further improvement of Phalaenopsis production in terms of greenhouse heating strategies in northern latitudes demands a better understanding of the planttemperature responses.…”

The Influence of Day and Night Temperature Fluctuations on Growth and Flowering of Annual Bedding Plants and Greenhouse Heating Cost Predictions

“…In temperate climates, high-energy inputs can be required to maintain a desirable greenhouse temperature, making fuel for heating one of the largest floriculture production expenses (Bartok, 2001). Greenhouse growers can reduce energy consumption by managing the greenhouse environment with dynamic temperature control (DTC) strategies (Körner et al, 2007;Lund et al, 2006). In DTC, in contrast to static temperature control, heating set points are lowered during periods when the greenhouse energy loss factor is high (e.g., outside temperature and incoming solar radiation are low) and increased when the energy loss factor is low (Körner et al, 2004).…”

“…This environmental control strategy integrates temperature and maintains a target MDT over a 1-to 7-d interval (Körner et al, 2004;Körner and Challa, 2003). Lund et al (2006) reported that a greenhouse in Denmark using DTC had 32% to 79% and 75% to 89% lower energy consumption for heating during winter and spring months, respectively, compared with a greenhouse using static temperature set points.…”

Low night temperatures change whole-plant physiology and increase starch accumulation inChrysanthemum morifolium

“…The amount of energy saved in a dynamic climate control system depended strongly on the night temperature required by a given plant species. Lund et al (2006) recently demonstrated that it is possible to produce a heat-demanding plant (Hibiscus rosa-sinensis) in a system where the temperature is allowed to drop to a minimum set-point of 15°C.…”