scholarly journals Effects of NIR Reflective Film as a High Tunnel-Covering Material on Fruit Cracking and Biomass Production of Tomatoes

Horticulturae ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 51
Author(s):  
Hiroko Yamaura ◽  
Shinichi Furuyama ◽  
Nobuo Takano ◽  
Yuka Nakano ◽  
Keiichi Kanno ◽  
...  
Keyword(s):  
Near Infrared ◽  
Morphological Changes ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Slight Reduction ◽  
High Tunnel ◽  
Fruit Cracking ◽  
Air Temperatures ◽  
Covering Material

Tomatoes require higher irradiance, although the incidence of physiological disorders in fruit increases at high temperatures. Near-infrared (800–2500 nm) (NIR) reflective materials are effective tools to suppress rising air temperatures in greenhouses. We examined the physiological and morphological changes in tomato growth and fruit quality when grown in a high tunnel covered with NIR reflective film (NR) and in another covered with polyolefin film (PO; control). There was no relationship between the fruit cracking rate and mean daytime temperature under NR. The fruit temperature at the same truss was lower and the increase in air temperature was slow under NR. Fruit dry matter (DM) content under NR was also significantly decreased. These findings suggest that the reduction in fruit cracking under NR results from a decrease in fruit DM content as a consequence of lower fruit temperature and a decrease in total DM (TDM). Total fruit yield did not differ, whereas TDM was significantly decreased under NR. This was considered to result from a lower transmitted photosynthetic photon flux density (400–700 nm) (PPFD) and LAI, and lower photosynthetic capacity in single leaves because of a decrease in both total nitrogen and chlorophyll content. We conclude that NR film reduces fruit cracking in exchange for a slight reduction in TDM.

scholarly journals Spectral Characterization of Difusse Par Irradiance under Tipuana Tipu Shading

2018 ◽  
Vol 75 (1) ◽  
pp. 19
Author(s):  
Gonzalo GURREA-YSASI ◽  
Vicente BLANCA ◽  
Ana FITA ◽  
Jaime PROHENS ◽  
Inmaculada FITA ◽  
...  
Keyword(s):  
Near Infrared ◽  
Infrared Region ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Tree Canopies ◽  
Common Tree ◽  
Soil Level

Tipa (Tipuana tipu) is a common tree in gardens and carparks, although the shading effect of its canopy must be still characterised to assess the decrease of temperature and quality of irradiance. This work is a preliminary study aimed to assess the effect of shading of tree canopies on the diffuse irradiance pattern received at the soil level in comparison to other conditions. The shade provided by a group of Tipa trees, located at the Universitat Politècnica de València (Valencia, Spain), was evaluated in this experiment and compared to cloudy days and direct sun. Photosynthetic Photon Flux Density (PPFD) and red/near infrared ratios were recorded with a portable spectrometer. Measurements were recorded in January and February 2017, at 10h, 13h and 16h. Depending on the region of the spectrum and time of the day, PPFD values ranged from 0.05 to 0.42, 0.40 to 1.14, and 0.94 to 3.90 μmol·m-2·s-1, for Tipa shade, cloudy days and direct sun, respectively. The spectral analysis of PPFD in cloudy days revealed maximum values in the green region and minimum at near infrared region, while maximum PPFD for tipa shade was mostly found at near infrared, revealing higher importance of this spectral region compared to cloudy days.

scholarly journals Light response and photosynthesis in sorghum under field conditions

MAUSAM ◽  
2022 ◽  
Vol 46 (3) ◽  
pp. 303-306
Author(s):  
Y. R. KENJLE ◽  
M. C. VARSHNEYA ◽  
T. R. U. NAIDU
Keyword(s):  
Correlation Coefficients ◽  
Light Response ◽  
Photosynthetic Photon Flux Density ◽  
Field Conditions ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Response Curves ◽  
Light Response Curves ◽  
Air Temperatures ◽  
Rate Of Photosynthesis

ABSTRACT. The diurnal variation of rate of photosynthesis (l') with photosynthetic photon flux density (PPFD) model of light response curves and the relationship between PPFD and P were studied for two postmonsoon (rabi) sorghum genotypes, viz.. M35- I and RSV-9R under field conditions at Pune. The half maximal values. i.e., PPFD level at which P=Pmax/2 obtained were 1251 and 937 umolm-2s-1 for M35-l and RSV.9R respectively. The potential rates of photosynthesis were 65,79 and 64.52  umolm-2S-1 whereas the observed maximum rates of photosynthesis were lower. 40.93 and 46.66 umolm-2s-1 in M35-1 and RSV-9R Respectively, due to effect of air temperatures under the field conditions, n1e maximum rate of photosynthesis determined from the model decreased with delay in the sowing of the crop. Correlation coefficients between PPFD and rate of photosynthesis were 0,794 and 0,708 for M35-1 and RSV-9R respectively. The PPFD received and rate of photosynthesis decreased significantly with delay in sorghum sowing.    

scholarly journals Potential Photosynthetic Advantages of Cucumber (Cucumis sativus L.) Seedlings Grown under Fluorescent Lamps with High Red:far-red Light

HortScience ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. 553-558 ◽  
Author(s):  
Toshio Shibuya ◽  
Ryosuke Endo ◽  
Yuki Kitamura ◽  
Yoshiaki Kitaya ◽  
Nobuaki Hayashi
Keyword(s):  
Cucumis Sativus ◽  
Morphological Changes ◽  
Red Light ◽  
Light Response ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Cucumis Sativus L ◽  
Fluorescent Lamps ◽  
Metal Halide Lamps

To evaluate the effect of fluorescent lamps with a high red:far-red (R:FR) light on the potential photosynthesis of transplants, we investigated the photosynthetic light responses of cucumber (Cucumis sativus L.) seedlings grown under fluorescent lamps with high R:FR light (FLH) and compared them with the responses of the seedlings grown under metal-halide lamps (ML) that provided a spectrum similar to that of natural light and under a fluorescent lamp with low R:FR light (FLL). The seedlings were grown under FLH (R:FR = 7.0), ML (R:FR = 1.2), or FLL (R:FR = 1.1) at a photosynthetic photon flux density (PPFD) of 350 μmol·m−2·s−1. The gross photosynthetic rate (Pg), quantum yield of photosystem II (ΦPSII), and photosynthetic electron transfer rate (ETR) of the foliage leaves were then evaluated at PPFDs ranging from 0 to 1000 μmol·m−2·s−1. The photosynthetic light response of FLH seedlings was similar to those of sun leaves, and the responses of ML and FLL seedlings were similar to those of shade leaves. The Pg, ETR, and ΦPSII of FLH seedlings at PPFD of 1000 μmol·m−2·s−1 was 1.38, 1.32, and 1.28 times, respectively, those of ML seedlings, and was 1.40, 1.23, and 1.22 times, respectively, those of FLL seedlings. The Pg was closely correlated with ETR in each treatment. FLH seedlings had thicker leaf and greater chlorophyll content per leaf area than ML and FLL seedlings. The greater Pg of FLH seedlings than in the other two groups of seedlings at high PPFD was probably the result of the improved ETR resulting from physiological and morphological changes in response to the high R:FR light.

scholarly journals Effect of Glasshouse Maintenance on the Quality of Irradiance Spectrum under Mediterranean Climates

2018 ◽  
Vol 75 (1) ◽  
pp. 21
Author(s):  
Gonzalo GURREA-YSASI ◽  
Vicente BLANCA ◽  
Jaime PROHENS ◽  
Pascual FERNÁNDEZ-DE-CÓRDOVA ◽  
Inmaculada FITA-FERNÁNDEZ ◽  
...  
Keyword(s):  
Near Infrared ◽  
Visible Region ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Uv C ◽  
Ornamental Species ◽  
Irradiance Spectrum

Glasshouses in Mediterranean areas are mainly used for experimental or nursery purposes and the production of high value ornamental species. In addition, glasshouses may be covered by dust and other particles in these areas as rainfalls are relatively scarce. Consequently, the quality of photosynthetically active radiation (PAR) may be affected. In the present experiment we evaluated the effect of dirt on the PAR spectrum in glasshouses in Valencia (Spain), compared to glasshouses submitted to suitable maintenance and washing. Photosynthetic Photon Flux Density (PPFD) measurements were done in March 2017 at 13h, and visible, UV-C and near infrared regions were recorded with a portable spectrometer. PPFD maximum values differed depending on the spectral region and glass conditions, with higher values corresponding to the visible region. Thus, clean glass showed values of 609, 588 and 423 μmol/m2s for PPFDR, PPFDG and PPFDB, respectively and 436 and 34 μmol/m2s for PPFDIR and PPFDUV. In comparison to clean glass, dirty glass decreased PPFD in all regions, particularly UV and blue region.

scholarly journals Characterization of the Spectrum of Solar Irradiance under Different Crop Protection Coverings in Mediterranean Conditions and Effect on the Interception of Photosynthetically Active Radiation

2018 ◽  
Vol 47 (2) ◽  
pp. 441-449
Author(s):  
Gonzalo GURREA-YSASI ◽  
Vicente BLANCA-GIMÉNEZ ◽  
Inmaculada C. FITA ◽  
Ana FITA ◽  
Jaime PROHENS ◽  
...  
Keyword(s):  
Open Field ◽  
Solar Irradiance ◽  
Near Infrared ◽  
Crop Protection ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Spectral Bands ◽  
Plant Cultivation ◽  
Growing Conditions

Plants use visible light and part of adjacent ultraviolet and near infrared regions for photosynthesis. Crop protection coverings enable plant cultivation in areas or seasons not suitable open field. However, the use of covering materials is a detriment to solar irradiance, which may decrease the photosynthetic rate. Here, the effect of two different covering materials, tempered glass and white polyethylene mesh, on solar irradiance was compared to open field (control) under real farming conditions. Relative irradiance (RI) and photosynthetic photon flux density (PPFD) were recorded along 380-780 nm wavelength spectrums in the two conditions at 10:00 h and 13:00 h. Also the efficiency of Capsicum peppers in capturing solar irradiance was evaluated in leaves as the reflectance of both RI and PPFD under the mentioned growing conditions. Low differences in RI among the three conditions were found, and the lowest values corresponded to glasshouse conditions. Differences were more obvious in PPFD and, compared to open field, both mesh greenhouse and glasshouse conditions provoked remarkable decreases in all the spectral bands, 50-55% and 75-80% respectively. Covering materials also differed on the ratio of reflected PPFD and incident PPFD. Glasshouse plants displayed the highest reflectance at both 10:00 h and 13:00 h (0.05-0.20), followed by mesh greenhouse (0.05-0.10), suggesting that glasshouse conditions might decrease the photosynthesis rate due to both PPFD decrease and reflectance, although the effect of polyethylene mesh should not be disregarded as it also decreases considerably PPFD. Our results have important implications for the physiology and the productivity of crops under different covering materials.

scholarly journals LED Illumination Spectrum Manipulation for Increasing the Yield of Sweet Basil (Ocimum basilicum L.)

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 344
Author(s):  
Md Momtazur Rahman ◽  
Mikhail Vasiliev ◽  
Kamal Alameh
Keyword(s):  
Growth Rate ◽  
Fold Increase ◽  
Photosynthetic Photon Flux Density ◽  
Ocimum Basilicum ◽  
Photon Flux ◽  
Photon Flux Density ◽  
White Led ◽  
Experimental Conditions ◽  
Sweet Basil ◽  
Optimal Illumination

Manipulation of the LED illumination spectrum can enhance plant growth rate and development in grow tents. We report on the identification of the illumination spectrum required to significantly enhance the growth rate of sweet basil (Ocimum basilicum L.) plants in grow tent environments by controlling the LED wavebands illuminating the plants. Since the optimal illumination spectrum depends on the plant type, this work focuses on identifying the illumination spectrum that achieves significant basil biomass improvement compared to improvements reported in prior studies. To be able to optimize the illumination spectrum, several steps must be achieved, namely, understanding plant biology, conducting several trial-and-error experiments, iteratively refining experimental conditions, and undertaking accurate statistical analyses. In this study, basil plants are grown in three grow tents with three LED illumination treatments, namely, only white LED illumination (denoted W*), the combination of red (R) and blue (B) LED illumination (denoted BR*) (relative red (R) and blue (B) intensities are 84% and 16%, respectively) and a combination of red (R), blue (B) and far-red (F) LED illumination (denoted BRF*) (relative red (R), blue (B) and far-red (F) intensities are 79%, 11%, and 10%, respectively). The photosynthetic photon flux density (PPFD) was set at 155 µmol m−2 s−1 for all illumination treatments, and the photoperiod was 20 h per day. Experimental results show that a combination of blue (B), red (R), and far-red (F) LED illumination leads to a one-fold increase in the yield of a sweet basil plant in comparison with only white LED illumination (W*). On the other hand, the use of blue (B) and red (R) LED illumination results in a half-fold increase in plant yield. Understanding the effects of LED illumination spectrum on the growth of plant sweet basil plants through basic horticulture research enables farmers to significantly improve their production yield, thus food security and profitability.

scholarly journals Plant buffering against the high-light stress-induced accumulation of CsGA2ox8 transcripts via alternative splicing to finely tune gibberellin levels and maintain hypocotyl elongation

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Bin Liu ◽  
Shuo Zhao ◽  
Pengli Li ◽  
Yilu Yin ◽  
Qingliang Niu ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Light Intensity ◽  
Intron Retention ◽  
Light Stress ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Rna Seq ◽  
Multiple Transcripts ◽  
Novel Transcript

AbstractIn plants, alternative splicing (AS) is markedly induced in response to environmental stresses, but it is unclear why plants generate multiple transcripts under stress conditions. In this study, RNA-seq was performed to identify AS events in cucumber seedlings grown under different light intensities. We identified a novel transcript of the gibberellin (GA)-deactivating enzyme Gibberellin 2-beta-dioxygenase 8 (CsGA2ox8). Compared with canonical CsGA2ox8.1, the CsGA2ox8.2 isoform presented intron retention between the second and third exons. Functional analysis proved that the transcript of CsGA2ox8.1 but not CsGA2ox8.2 played a role in the deactivation of bioactive GAs. Moreover, expression analysis demonstrated that both transcripts were upregulated by increased light intensity, but the expression level of CsGA2ox8.1 increased slowly when the light intensity was >400 µmol·m−2·s−1 PPFD (photosynthetic photon flux density), while the CsGA2ox8.2 transcript levels increased rapidly when the light intensity was >200 µmol·m−2·s−1 PPFD. Our findings provide evidence that plants might finely tune their GA levels by buffering against the normal transcripts of CsGA2ox8 through AS.

scholarly journals Effects of Light Quality on the Chlorophyll Degradation Pathway in Rice Seedling Leaves

2016 ◽  
Vol 44 (2) ◽  
pp. 393-398
Author(s):  
Chang-Chang CHEN ◽  
Kuan-Hung LIN ◽  
Meng-Yuan HUANG ◽  
Wen-Dar HUANG ◽  
Chi-Ming YANG
Keyword(s):  
Light Quality ◽  
Protoporphyrin Ix ◽  
Degradation Pathway ◽  
Photosynthetic Photon Flux Density ◽  
Rice Seedling ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Rice Seedlings ◽  
Rice Varieties ◽  
Enriched Environments

The objective of this study was to investigate the dynamics of chlorophyll (Chl), biosynthetic intermediates (protoporphyrin IX, magnesium protoporphyrin IX, and protochlorophyllide), degradation intermediates [chlorophyllide (Chlide), pheophytin (Phe), and pheophorbide (Pho)], and carotenoids (Car) in leaves of rice seedlings. Two rice varieties, 'Taichung Shen 10' ('TCS10') and 'IR1552', were grown under different light quality conditions controlled by light emitting diodes (LED). Lighting treatments for rice seedlings were included by red (R), blue (B), green (G), and red + blue (RB), with fluorescent lighting (FL) as the control and photosynthetic photon flux density being set at 105 µmol m-2 s-1. The results show that lower levels of Chl and Car in leaves were detected under G lighting, and light quality did not mediate porphyrins in biosynthetic pathways. Rice seedling leaves took Chl→Phe→Pho and Chl→Chlide→Pho as the major and minor degradation routes, respectively. Furthermore, higher Phe/Chlide ratios were observed under G and FL lighting conditions, indicating that green-enriched environments can up-regulate the minor degradation route in leaves.

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