NL: Cygnus Greenhouse Control

For more than 30 years Hotraco has been manufacturing and supplying control systems, which provide both reliability and excellent value to their products. The experience gained in combination with the latest technology, provides a guarantee for state-of-the-art Hotraco products.

The CYGNUS-CO2 is a computer which is suitable for greenhouses to control on/off heating and guard temperature, relative air humidity and CO2 level. The computer can be set with day / night time option incase need different settings are required.

If needed, extra CO2 can be produced by the heating unit when CO2 level becomes too low during the day. When CO2 level and / or temperature becomes too high, the windows can be opened or ventilation can be switched on.

Also it is possible to control the humidification when a humidity sensor is connected to the CYGNUS-CO2. At a low relative air humidity, the humidifier can be switched on, or when it gets to high extra ventilation can be applied.

Furthermore, the CYGNUS is provided with an alarm contact which activates an alarm when temperature, CO2 or relative humidity exceeds set values. The control communicates with clear language independent symbols that immediately make sense to the user.

Sources:
FreshPlaza.com
Hotraco Horticulture

Carbon Dioxide Enrichment of Iron-Stressed Tomato Plants

Reference: Jin, C.W., Du, S.T., Chen, W.W., Li, G.X., Zhang, Y.S. and Zheng, S.J. 2009. Elevated carbon dioxide improves plant iron nutrition through enhancing the iron-deficiency-induced responses under iron-limited conditions in tomato. Plant Physiology 150: 272-280.

What was done: The authors grew twenty-day-old plants for an additional seven days within controlled-environment chambers maintained at atmospheric CO2 concentrations of either 350 or 800 ppm in an iron (Fe)-sufficient medium with a soluble Fe source or under Fe-limited conditions in a medium containing the sparingly soluble hydrous Fe(III)-oxide, while measuring a number of pertinent plant parameters.

What was learned: Plant growth was increased by the elevated CO2 in both the Fe-sufficient and Fe-limited media, with shoot fresh weight increasing by 22% and 44%, respectively, and root fresh weight increasing by 43% and 97%, respectively. In addition, Jin et al. report that "the elevated CO2 under Fe-limited conditions enhance[d] root growth, root hair development, proton release, root FCR [ferric chelate reductase] activity, and expressions of LeFR01 and LeIRT1 genes [which respectively encode FCR and the Fe(II) transporter in tomato], all of which enable plants to access and accumulate more Fe." And they add, as would be expected, that "the associated increase in Fe concentrations in the shoots and roots alleviated Fe-deficiency-induced chlorosis."

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The Rooting of Woody Plant Cuttings

What was done: The authors investigated the effects of enriching the air with CO2 to just under 1000 ppm on the rooting of branch cuttings of two flower cherries (Prunus incisa and Prunus jamasakura), one endangered five-needle pine (Pinus armandi var. amamiana), seven nematode-resistant clones of Pinus densiflora and three nematode-resistant clones of Pinus thunbergli, as well as Pistacia chinensis. Read more>

Increased yields through better CO2 use in plants

BASF Plant Science and the University of Cologne cooperate in plant biotechnology Aim is to increase yields and improve stress tolerance in crops

8 Jul 2009 , Limburgerhof, Cologne, Germany : BASF Plant Science and the Botanical Institute of the University of Cologne announce that they have entered a cooperation in plant biotechnology. Focus is on plant traits that increase the yield of crops like soybeans, rice, and canola and improve their tolerance to adverse environmental conditions like cold, drought or salinization. The cooperation comprises both a license and an R&D agreement, which were negotiated by PROvendis, the patent marketing company for North Rhine-Westphalia’s universities.

Together with BASF Plant Science, Prof. Dr. Ulf-Ingo Flügge and Dr. Verónica G. Maurino from the Botanical Institute of the University of Cologne are working on optimizing the energy generation of key global crops. During photosynthesis, the process where carbon dioxide (CO2) is converted into carbohydrates (e.g. starch), many plants don't make optimum use of the CO2 in the air. Certain types of plants, like corn, are able to use more CO2 through an additional metabolic process. The objective of the current research project is to transfer this biochemical mechanism to other plants. The Cologne-based researchers have already been successful in genetically modifying a test plant, the so-called thale cress (Arabidopsis thaliana). Thanks to the inserted genes, the plant produces special enzymes which ensure that the plant uses more carbon dioxide resulting in the production of more biomass.

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Effects of Elevated CO2 on Rice Leaves

ReferenceLi, J.-Y., Liu, X.-H., Cai, Q.-S., Gu, H., Zhang, S.-S., Wu, Y.-Y. and Wang, C.-J. 2008.

Effects of elevated CO2 on growth, carbon assimilation, photosynthate accumulation and related enzymes in rice leaves during sink-source transition. Journal of Integrative Plant Biology 50: 723-732.

What was done
The authors measured several physiological processes -- including dynamic changes in photosynthesis and photosynthate accumulation, as well as enzyme activities such as sucrose phosphate synthesis (SPS) and sucrose synthase (SS) and their specific gene (SPS1 and RSus1) expressions -- in both mature (leaf 6) and developing (leaf 7) foliage of plants growing hydroponically in nutrient solutions within controlled-environment chambers maintained at atmospheric CO2 concentrations of 350 or 700 ppm throughout the entire week of leaf 6 development and expansion.

What was learned
Li et al. determined that "elevated CO2 significantly increased the rate of leaf elongation and biomass accumulation of leaf 7 during the treatment without affecting the growth of leaf 6." Over days 4-7, for example, the net photosynthetic rates of the mature leaves were increased by an average of 15% by the CO2 enrichment provided them, while the mean dry weight of the developing leaves in the CO2-enriched air was 100% greater than it was in the developing leaves in ambient air on day 2, dropping to 50% greater on day 3, and leveling out at 15% greater on days 5-7, equivalent to the same stimulation provided concurrently to the process of photosynthesis in the mature leaves. In addition, they say that in both developing and mature leaves, the net photosynthetic assimilation rate, all kinds of photosynthate contents (such as starch, sucrose and hexose), activities of SPS and SS, plus transcript levels of sps1 and RSus1, "were significantly increased under elevated CO2."

What it means
The seven researchers concluded that the "elevated CO2 had facilitated photosynthate assimilation, and increased photosynthate supplies from the source leaf [six] to the sink leaf [seven], which accelerated the growth and sink-source transition in new developing sink leaves." Put another way, mature rice leaves provide all sorts of CO2-enhanced help to developing leaves as the growth process proceeds; and they should continue to do so in an ever-increasing fashion as the air's CO2 content continues to rise, which is good news for rice ... and even better news for humanity.

Reviewed 17 June 2009

Salinity Stress in Tomato Plants

ReferenceTakagi, M., El-Shemy, H.A., Sasaki, S., Toyama, S., Kanai, S., Saneoka, H. and Fujita, K. 2008.

Elevated CO2 concentration alleviates salinity stress in tomato plant. Acta Agriculturae Scandinavica Section B - Soil and Plant Science: 10.1080/09064710801932425.

What was done
The authors grew well watered and fertilized tomato [Solanum lycopersicum (formerly Lycopersicon esculentum) L. cv. Momotarou] seedlings for two weeks at two different levels of irrigation-water salinity (0 or 100 mM NaCl) in 3-L pots inside the greenhouse of Hiroshima University, Japan, at atmospheric CO2 concentrations of either 370 or 1000 ppm, while measuring various plant properties and physiological responses.

What was learned
Takagi et al. report that "salt-stress treatment severely decreased whole-plant biomass," as well as "leaf photosynthesis and transport of carbon assimilates," but that "the impact of stress on these activities was alleviated under elevated CO2 concentration." This alleviation, as they describe it, "was promoted when sink activity relative to source activity was higher," which they say was "probably owing to improvement of oxidative stress," due "at least partially to the higher constitutive antioxidant enzymes' activities," as well as improved water status "through stomatal closure at high CO2 concentration."

What it means
The seven scientists state that their study "corroborates earlier reports that the interaction between salinity stress and CO2 concentration result[s] in the alleviative effect of elevated CO2 on the negative effects of salinity on plant growth," for which conclusion much additional evidence is archived under the heading of Salinity (Effects on Plants) in our Subject Index. Hence, we have yet another indication of the ability of earth's plants to function ever more robustly and to successfully overcome various environmental challenges as the air's CO2 content continues to climb ever higher.

Reviewed 17 June 2009