{"id":14803,"date":"2026-05-04T10:07:26","date_gmt":"2026-05-04T10:07:26","guid":{"rendered":"https:\/\/www.proefschriftmaken.nl\/portfolio\/elena-vincenzi\/"},"modified":"2026-05-04T10:07:44","modified_gmt":"2026-05-04T10:07:44","slug":"elena-vincenzi","status":"publish","type":"us_portfolio","link":"https:\/\/www.proefschriftmaken.nl\/en\/portfolio\/elena-vincenzi\/","title":{"rendered":"Elena Vincenzi"},"content":{"rendered":"","protected":true},"excerpt":{"rendered":"","protected":true},"author":7,"featured_media":14804,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"us_portfolio_category":[45],"class_list":["post-14803","us_portfolio","type-us_portfolio","status-publish","post-password-required","hentry","us_portfolio_category-new-template"],"acf":{"naam_van_het_proefschift":"Far-red in greenhouse tomato cultivation","samenvatting":"De tomaat is een wereldwijd belangrijk gewas voor zowel verse consumptie als verwerkte producten en dient tevens als modelsoort voor fysiologische studies aan vlezige vruchtdragende planten. In noordelijke landen vindt de tomatenproductie voornamelijk plaats in beschermde omgevingen zoals kassen, waar jaarrond teelt wordt gerealiseerd door verwarming en aanvullende verlichting tijdens de wintermaanden. Omdat de glastuinbouwsector streeft naar meer duurzaamheid zonder de opbrengst in gevaar te brengen, verschuift de aanvullende verlichting naar energiezuinige LED's, die nauwkeurige controle van zowel de lichtintensiteit als de spectrale samenstelling mogelijk maken. De huidige recepten voor aanvullende verlichting voor tomaten worden gedomineerd door rood licht, met kleine aandelen blauw en groen, en missen doorgaans verrood (FR, 700-800 nm). De toevoeging van FR aan aanvullende verlichting heeft het potentieel om de vruchtopbrengst te verhogen door de biomassa-accumulatie en de toewijzing ervan aan het oogstbare product - de vrucht - te verbeteren. FR kan de fotosynthese aandrijven wanneer het samen met kortere golflengten wordt geleverd. Bovendien kan FR-perceptie door fytochromen fotomorfogenetische reacties teweegbrengen, waardoor meerdere plantprocessen veranderen. Dit proefschrift beoogt de fysiologische mechanismen die ten grondslag liggen aan de door FR gemedieerde bevordering van de vruchtgroei te verbinden met optimale toepassingsstrategie\u00ebn.\n\nHoofdstuk 1 introduceert de botanische kenmerken van tomatenplanten en de hormoon- en koolhydraatdynamiek. Hoofdstuk 2 toont aan dat de vruchtopbrengst proportioneel toenam met de duur van de FR-toepassing tijdens de fotoperiode. Hoofdstuk 3 onderzoekt de dosis-respons van de vruchtopbrengst op FR; de opbrengst nam lineair toe tot een FR-fractie van 0,40, waarna het effect stabiliseerde of afnam. Hoofdstuk 4 onderzoekt de locatie van FR-toepassing. FR binnen het bladerdek verhoogde de verdeling naar de vrucht sterker, terwijl FR boven het bladerdek de biomassa-accumulatie bevorderde. De combinatie van beide leverde de hoogste opbrengst op. Hoofdstuk 5 toont aan dat FR-perceptie door vegetatieve organen de vruchtgroei aanstuurt via systemische signalering, wat leidt tot een hogere vruchtopbrengst en suikergehalte. Hoofdstuk 6 integreert de bevindingen met bestaande literatuur en biedt praktische aanbevelingen voor de glastuinbouw.","summary":"Tomato is a globally important crop for both fresh consumption and processed products, and it also serves as a model species for physiological studies on fleshy fruit-bearing plants. In northern countries, tomato production takes place mostly in protected environments like greenhouses, where year-round cultivation is achieved through heating and supplementary lighting during the winter months. As the greenhouse sector aims to increase its sustainability without compromising yield, supplementary lighting is shifting toward energy-efficient LEDs, which allow precise control of both light intensity and spectral composition. Current supplementary lighting recipes for tomato are dominated by red light, with small proportions of blue and green, and typically lacking far-red (FR, 700\u2013800 nm). The addition of FR to supplementary lighting has the potential to increase fruit yield by improving biomass accumulation and its allocation to the harvestable product: the fruit. Despite being outside of the photosynthetically active radiation (PAR, 400\u2013700 nm) region, FR can drive photosynthesis when supplied together with shorter wavelengths (\u201cFR as photon\u201d). In addition, FR perception by phytochromes can trigger photomorphogenic responses, altering multiple plant processes from architecture to biomass partitioning to defence (\u201cFR as signal\u201d). The multifaceted nature of FR complicates the interpretation of its effects at the molecular, plant, and crop levels. This thesis aims to connect the physiological mechanisms underlying FR-mediated fruit growth promotion with optimal application strategies in a realistic horticultural setting, with the ultimate goal of maximising the effectiveness of FR supplementation for improving tomato fruit yield.\n\nChapter 1 introduced the main botanical characteristics of tomato plants and outlined the hormonal and carbohydrate dynamics controlling fruit growth and development. The history of tomato cultivation and current horticultural practices were described and connected to the long-term objectives for this sector. Thereafter, the photosynthetic and photomorphogenic effects of FR were explained and linked to the fruit-yield responses observed when FR is added to standard lighting recipes for tomato production. Finally, the overarching aim of the thesis was presented, followed by the specific hypotheses and research questions addressed in each chapter.\n\nChapter 2 demonstrated that tomato fruit yield increased proportionally with the duration of FR application during the photoperiod. Applying the same daily light integral of FR (light intensity \u00d7 duration) during either the first or second half of the photoperiod did not influence plant dry weight production, dry matter partitioning to fruit, or fruit yield. Fruit production per unit of supplementary photon flux density was comparable between the treatments with and without FR. Therefore, adding FR to a PAR background increased fruit yield with the same efficiency as PAR, without compromising fruit quality at harvest.\n\nChapter 3 examined the dose\u2013response of fruit yield to FR by establishing a gradient of FR fractions. Fruit yield increased linearly with the FR fraction from 0.22 to 0.40. Beyond this level, ripe fruit dry weight production plateaued, while the dry matter content continued to rise, ultimately reducing yield. These results identified a practical upper limit for effective FR supplementation, as both radiation use efficiency and electricity use efficiency decreased above a FR fraction of 0.40. Even at the highest FR fractions tested, FR showed minimal effects on fruit quality and shelf-life.\n\nChapter 4 investigates how the location of the FR application, above or within the canopy, affected plant responses. Intracanopy FR increased dry matter partitioning to fruit and enhanced fruit sink strength more strongly than top-canopy FR. However, top-canopy FR also promoted plant biomass accumulation, resulting in higher fruit yield. Combining top and intracanopy FR application produced the greatest yield gains by maximising both dry weight production and partitioning to the fruit. Since light interception and distribution within the canopy were not altered by the treatments, FR effects on leaf-level photosynthesis (in detached leaves) were assessed to determine the origin of the plant biomass increase. Long-term acclimation to FR reduced chlorophyll index and increased specific leaf area, with only minor effects on leaf absorptance. Overall, acclimation to FR, whether applied above or within the canopy, did not affect the maximum quantum yield of photosynthesis in top- or mid-canopy leaves, nor did it interact with short-term FR effects. In the short-term (instantaneous effects), FR increased leaf CO\u2082 assimilation by 4 to 10%, but FR photons were less efficient than PAR photons in driving photosynthesis, largely due to lower leaf absorptance of FR.\n\nChapter 5 demonstrated that FR perception by vegetative organs, including leaves, stem, and apex, drives fruit-growth responses to FR. Vegetative FR perception increased dry matter partitioning to fruit, fruit fresh and dry weight, and soluble sugar content in ripe tomatoes, whereas FR applied exclusively to generative organs had no effect. The signalling mechanism between FR-perceiving organs and the fruit was further investigated with a time-course RNA-sequencing experiment. Leaf responses to FR perception included a transient increase in auxin levels and activation of the auxin signalling pathway, together with upregulation of light-, hormone-, and transcription-related genes. In early-developing tomatoes, \u201cearly\u201d response (24\u201348h post FR) to FR signalling, not perception, suggested a role for hormones as mediators of fruit growth responses. \u201cLate\u201d fruit responses (48\u201396h post FR) showed an increase in sucrose import rate and starch biosynthesis, with a general upregulation of carbon metabolism for energy, storage, and photosynthesis.\n\nChapter 6 integrated the findings of this thesis with scientific literature, from molecular signalling to crop-level performance. Differences between FR responses in young vegetative and fruiting tomato plants were mentioned, highlighting the need for more research in fruiting plants. The effects of timing and dose of FR application were discussed in relation to interactions with solar radiation. The mechanisms underlying FR perception by vegetative organs were linked to fruit sink strength responses under different locations of FR application. Known FR effects on leaf photosynthesis were reviewed, and FR-driven regulation of fruit chlorophyll and photosynthesis-related genes was discussed. FR effects on fruit quality were evaluated, and strategies to possibly increase yield gains by managing fruit dry matter content were proposed. The efficiency of supplementary FR, in terms of both radiation use and electricity use efficiency, was synthesised based on the current state and future projections of LED development, and the application of FR for crop production and breeding was discussed on a broader level. Finally, practical recommendations for FR application in greenhouse tomato production and directions for future research were provided, together with the overall conclusions of this thesis.","auteur":"Elena Vincenzi","auteur_slug":"elena-vincenzi","publicatiedatum":"27 mei 2026","taal":"EN","url_flipbook":"https:\/\/ebook.proefschriftmaken.nl\/ebook\/elenavincenzi?iframe=true","url_download_pdf":"https:\/\/ebook.proefschriftmaken.nl\/download\/db9842f3-02be-4162-ab48-3dbcc719b32a\/optimized","url_epub":"","ordernummer":"18473","isbn":"","doi_nummer":"","naam_universiteit":"Wageningen University","afbeeldingen":14805,"naam_student:":"","binnenwerk":"","universiteit":"Wageningen University","cover":"","afwerking":"","cover_afwerking":"","design":""},"_links":{"self":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/14803","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio"}],"about":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/types\/us_portfolio"}],"author":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/comments?post=14803"}],"version-history":[{"count":1,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/14803\/revisions"}],"predecessor-version":[{"id":14806,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio\/14803\/revisions\/14806"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/media\/14804"}],"wp:attachment":[{"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/media?parent=14803"}],"wp:term":[{"taxonomy":"us_portfolio_category","embeddable":true,"href":"https:\/\/www.proefschriftmaken.nl\/en\/wp-json\/wp\/v2\/us_portfolio_category?post=14803"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}