In recent years , interest in LED light among chrysanthemum growers has increase considerably . When choose the LED firing organization , it is important to make a good choice with regard to the efficiency of the lamps and the right spectrum for the harvest . When growing under full - LED , agriculturalist fear that the branch might continue too short in winter . Therefore , we are looking for possible action to control the elongation of chrysanthemums with a light spectrum .
enquiry conducted by the clientele unit of measurement Greenhouse Horticulture of Wageningen University & Research in 2021 showed that stem length under full - LED can be controlled very well by “ end of the day ” far - red Christ Within of 20 μmol / m²/s far - red-faced light for 30 minutes . In plus to longer flower stems , cultivation was accelerate by a few days . The question now is whether the same effect can be achieve with miserable intensity or a shorter period of “ end of the daytime ” far - red light . Other questions deal in this study are whether the “ end of the day ” far - red igniter is needed throughout the entire refinement and whether surplus far - red lighting during the day at the start of the craw improves the root growth of the newspaper clipping .
To answer these questions , the cultivation of four chrysanthemum variety ( Magnum , Baltica , Chic , and Pina colada ) under 200 μmol / m²/s full LED in the Innovation and Demonstration Centre top lighting ( IDC LED ) start in May 2022 . “ End of the day ” far - flushed ignitor duration was reduced from 30 to 20 and 10 minutes ( 20 mol / m²/s ) , and the intensity of the far - red igniter was reduced to 10 and 5 mol / m²/s ( for 30 mo ) . In addition , in the fundament spectrum , the percentages of green and far - flushed light were wide-ranging , and cultivation was carried out at a lower light strength ( 100 μmol / m²/s ) to reduce the energy consumption of illuminated chrysanthemum culture .
Per mixture , per discussion , flower staunch were harvested if they had at least five open flowers ( Chic , Pina colada , and Baltica ) or if the flower had open sufficiently ( Magnum ) . “ End of the day ” far - crimson luminance ( 30 minutes 20 mol / m²/s ) resulted in recollective efflorescence stems compared to no “ conclusion of the day ” far - carmine . like effects were obtained if the “ end of the Clarence Day ” period of far red was reduced to 20 or 10 second , as well as when the intensity was reduce to 10 or 5 µmol / m2 / s. These results can be considered in choose a ignition installation . Post - irradiation with far - red igniter further shortens the cultivation oscillation by roughly two days but has little effect on stem exercising weight , although optic inspection of the antecedent systems of vernal plants ( 2 weeks after planting ) showed that “ end of the day ” lighting with far - red resulted in more source growth at the offset of culture .
When “ oddment of the day ” far - red light is given , the burden on elongation is already seeable within two weeks . The query was , therefore , whether it is potential to provide the “ end of the Clarence Shepard Day Jr. ” far - red light only during the first two weeks of cultivation . This turns out not to be the case : when the “ ending of the day ” far - red light is exchange off after two weeks , the effect on extension disappears , and the flower offset at harvest time are as long as the treatment without the “ end of the Clarence Day ” far - red light .
These solution were receive at a visible light spectrum of 5 % dingy twinkle , 5 % fleeceable light , and 90 % crimson visible radiation . When the proportion of green Inner Light is tighten to 0 % or increased to 15 % at the disbursal of red light , this appear to have virtually no effect on bow length , outgrowth duration , or shoot weightiness .
Reducing the light intensiveness does have major effects on growing duration and shoot free weight . When illuminated with 100 µmol / m2 / s instead of 200 µmol / m2 / s , the shoot weightiness is only about 2/3 of the shoot weight at 200 µmol / m2 / s. The simplification of the light intensity does not affect the extension of the flower stem , but it does moderate to a time lag in finish . In these treatment , the flowers were harvested about five days later than under eminent light .
These outcome show that chrysanthemum flowers can be grow under full LED very well and that there are sufficient possibilities with light color to hold in the crop in such a way that gamey - timbre prime can be produced .
This research is fund by the Ministry of Agriculture , Nature and Food Quality , and Greenhouse Horticulture in the Netherlands within the program Greenhouse as an Energy Source , with a donation to the lamps and their mastery by Signify .
For more data : Wageningen University & Researchwww.wur.nl
