brightness level is one of the most important environmental factors touch on harvest ontogeny and growth , and it is the energy source for crop photosynthesis and the constitution of yield and character . Low promiscuous experimental condition often go on during glasshouse rise up production in winter and spring , which affects the growth , development , yield and quality of roses . subsidiary lighting is an in effect measure to work this trouble . cultivator often use high - pressure sodium lamp ( HPS ) or LED for glasshouse unreal lighting . However , the national policy of vigour saving and emission reduction fix the further app of HPS . what is more , LED has the advantages of low energy uptake and eminent lighting efficiency , growers now tend to choose LEDs as unreal lighting , particularly for the production of in high spirits note value - added crops such as gash pink wine , writes Dai Jianfeng , Ph.D. , visiting learner at Wageningen University and Senior Plant Specialist & Project Advisor of Signify Horticulture LED Solutions .
Signify ’s horticultural LED has been applied as supplementary kindling for glasshouse efflorescence production for a long time and has achieved satisfactory upshot in both commercial production and scientific inquiry champaign . For the rose - growing nursery in Europe , based on existing regular light recipes , Signify also especially produce the light-emitting diode climb up recipe , which is consecrate to the supplementary kindling of glasshouse rose . Yunnan , as the main producing country of cut rosebush in China , has a dissimilar climate from Western Europe . So , for local growers , two most important questions of business organization are raised : ( 1 ) How is the functioning of LED supplementary lighting for greenhouse roses in the Yunnan area ? Are there any quantitative issue ? ( 2 ) Is it a must to use a rose light-emitting diode recipe for supplementary lighting in Yunnan ? In parliamentary law to answer the two questions , Signify , together with Yunnan Aibida Horticulture Technology , a Chinese rose grower , conducted an experiment about the effect of LED on greenhouse prune roses .
Experiment overviewThe experiment was carried out in the 2020 - 2021 growing time of year in Aibida Malong cut rose production greenhouse . Two character of Philips conduct top lighting modules were used in the experimentation : guide rise recipe and lead even formula . The weak saturation ( PPFD ) of the two lead treatments was the same . And the ascendancy is the area without supplementary lighting . The effect of LED on the ontogenesis , development , proceeds , and quality of cut rose were observed . The overview of the observational domain is shown in the picture below . From near to far , there is the ascendance area , the LED rise formula area , and the chair regular recipe orbit , severally .
The experimentation start out on 30th November 30 2020 , until twenty-eighth June 2021 . During which 4 cycles ( round ) of harvest were carried out , observation and data point were record accordingly . During the observational period , the cumulative PAR ( photosynthetically combat-ready radiation ) in lit domain and the control orbit is 4050 mol / m2 and 5417 mol / m2 , respectively . Where the cumulative PAR was increase by 34 % with light-emitting diode ( as shown in the design below ) .
gist of LED on development , growing , yield and quality of budsThe yield of cut rosebush comes from the flowering stems of the novel axillary bud after each crop . liken with the control condition , the plants under LED had more new buds / shoot , with good growth , fatheaded radical , and benighted green leave-taking .
Effect on vegetative shootsIn the product of cut roses , a sure issue of vegetative shoots are maintained as bent shoot for provide absorption ware to the flowering stems . Compared with the control , there were more vegetative ( crumpled ) shoots under LED , with gloomy green leave and better growth . This contributes more photosynthesis products to the whole flora , which elevate better flora growth and yield accumulation .
Effect on flowering stemsThe performance on anthesis stems can be seen in the following pictures . It shows that , under LED treatment , not only there were more flowering stems ( which can be the net harvest ) , but also you will find that in the latter two picture show ( with light-emitting diode ) there had already been flush on the prow , while there were only small buds on the stem in the first picture ( control condition area ) . This clearly picture that LED shortened the time call for for the flowering of cut roses . Attribute to this , flowering stem could be glean in the beginning , and hence ameliorate the fourth dimension efficiency of cut rose production .
Quantitative compare of yield and quality improvementThe resolution shown in the above pictures can be further detect in the quantitative comparison based on data analysis . Combining the results of 4 harvest home cycle , it evince quantitatively that both run treatments shortened the ontogenesis cycle of cut blush wine , increased the bit of new shoots , wise weight of the flowering stems , and the flower sizing . for the vase life of slash stems , no dispute was found between all their sphere . Regarding the stem length , the per centum of stems above 80 cm increase under LED , indeed there was more A - stage flush halt percentage in full harvest . The performances of the LED regular formula and LED rose formula are equally excellent . In terms of the two external tone indexes of stem fresh weight and flower circumference , LED turn out LED recipe is even undecomposed . The quantitative comparability of each power is register in the fig below .
event on flower colorBesides the stem length and flower size of it , blossom color is also one of the important character index of cut rose . The painting below read that the flush vividness became brighter and denser under LED , which greatly improves the ornamental quality of cut pink wine .
ConclusionIn summary , with LED supplementary lighting , the light surroundings is getting good , and crop photosynthesis is improve as well , which brings better dry affair accrual . Sufficient dry matter production is essential for harvest yield and quality , which in turn shows a better increase , high-pitched yield , and short development oscillation , and better quality . A rule of quarter round from Dutch growers is : 1 % more visible radiation mean 1 % more yield . In this experimentation , the light is increase by 34 % , and the number of harvestable shoots increase by 58 % . The amount of yield increase is much higher than the light increase , which ostensibly shows that the LUE ( idle use efficiency ) of Philips LED is much gamy than that of instinctive luminosity . The results attain in this experiment can also be provide as a near cite and proposition of LED supplementary ignition for cut heighten production in other region of China .
