Effect of Light Intensity, Carbon Dioxide Concentration, and Leaf Temperature on Gas Exchange of Spray Carnation Plants

Abstract

The rates of CO2 assimilation by potted spray carnation plants (cv. Cerise Royalette) were determined over a wide range of light intensities (45-450 W m~2 PAR), CO2 concentrations (200-3100 vpm), and leaf temperatures (5-35 °C). Assimilation rates varied with these factors in a way similar to the response of single leaves of other temperate crops, although the absolute values were lower. The optimal temperature for CO2 assimilation was between 5 and 10 °C at 45 W m~2 PAR but it increased progressively with increasing light intensity and CO2 concentration up to 27 °C at 450 W m~2 PAR and 3100 vpm CO2 as expressed by the equation 2\>pt = -6-47 + 2-336 In C + 0-031957 where C is CO 2 concentration in vpm and I is photosynthetically active radiation in W m~2. CO2 enrichment also increased stomatal resistance, especially at high light intensities.The influence of these results on optimalization of temperatures and CO2 concentrations for carnation crops subjected to daily light variation, and the discrepancy between optimal temperatures for growth and net photosynthesis, are discussed briefly.

Carbon Dioxide and Agricultural Yield: An Assemblage and Analysis of 430 Prior Observations1

“…Considering spe- cific differences between greenhouses (or growth chambers) and open fields, the environments in greenhouses generally have more (1) ideal temperature, (2) optimum humidity and soil moisture, (3) adequate nutrients, and ( 4) reduced solar radiation. With respect to temperature, the data probably adequately represent the field because photosynthesis responses to changing C0 2 concentration are not markedly different at different temperatures over a range at which the crops are normally grown (Gaastra, 1959;Enoch and Hurd, 1977). The more ideal moisture conditions in greenhouses also do not invalidate the data because the two C0 2 enrichment studies which included moisture stress as a variable showed that water-stressed wheat responded to C0 2 about as much or more than well-watered wheat (Gifford, l979a, l979b;Sionit et al, 1980).…”

“…With respect to solar radiation, the data may also be biased, but in the direction opposite of that for nutrients. Photosynthesis and yield increase more with C0 2 enrichment at the higher light intensities characteristic of field conditions than at the lower intensities typical of greenhouses, particularly in winter (Gaastra, 1979;Enoch and Hurd, 1977;Kimball and Mitchell, 1979). Also, under the highest light intensities many of the greenhouses were not enriched, because ventilation was used for temperature control, in contrast to future fields which will have higher C0 2 concentrations continuously.…”

The Effects of Day and Night Temperature on the Dry Matter Accumulation of Oriental Hybrid Lily ‘Siberia’ as they Relate to the Photosynthetic and Respiratory Characteristics

“…3A). As shown in carnation (Enoch & Hurd 1977) and rose (Jiao et al 1991), the optimum temperature for PR decreases as the light intensity decreases. The stems and bulb roots of plants grown under high DT of 28°C had a significantly low DW (Fig.…”

Interaction of Co2 and Environmental Factors on Crop Responses

“…Normally net photosynthesis (Pn) increases with increasing CO2 concentrations up to a point of saturation where further increases in CO2 do not increase Pn. As CO2 concentration or irradiance increases, the optimum temperature for maximum Pn also increases (Gaastra, 1959;Enoch and Hurd, 1977). Wittwer and Robb (1964) recommended that greenhouse daytime temperature be elevated 3 to 5.5°C during CO2 enrichment.…”