Competition, light quality and seedling growth of Russian wildrye grass (Psathyrostachys juncea)

2007 ◽  
Vol 55 (1) ◽  
pp. 49-60 ◽  
Author(s):  
P. Jefferson ◽  
R. Muri
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Light Quality ◽  
Red Light ◽  
Dry Weight ◽  
Tiller Number ◽  
Seedling Vigour ◽  
Psathyrostachys Juncea ◽  
Growth Room ◽  
Russian Wildrye

The low seedling vigour of Russian wildrye grass ( Psathyrostachys juncea ) (RWR) limits its use. Shading from durum wheat ( Triticum turgidum ) reduced RWR leaf number, tiller number, leaf area and seedling dry weight in a growth room experiment. Treatments with similar shading differed in tiller number and dry weight, which suggested that light quality may have also contributed to these responses. In a second growth room experiment, light intensity (PAR) and red:far-red light ratio (670:730 nm) were altered by coloured plastic filters suspended above seedlings of Russian wildrye, crested wheatgrass ( Agropyron desertorum ) (CWG) and Dahurian wildrye grass ( Elymus dahuricus ) (DWR). Leaf area, tiller number and dry weight of RWR seedlings were reduced by declining red:far-red light ratio while light intensity differences at similar red:far-red ratio did not affect these variables. CWG exhibited similar responses to declining red:far-red light ratio as RWR, except that it exhibited a seedling weight response to light intensity. DWR tiller number was not responsive to low red:far-red light ratio but rather to low light intensity. However, DWR seedling weight, tiller weight and leaf area were responsive to declining red:far-red light ratio. These results indicate that RWR seedlings are sensitive to light quality changes caused by neighbouring plants.

scholarly journals The growth of three varieties of black pepper (Piper nigrum) under different light intensities related to indigenous hormones role

2020 ◽  
Vol 21 (5) ◽  
Author(s):  
Issukindarsyah Issukindarsyah ◽  
Endang Sulistyaningsih ◽  
Didik Indradewa ◽  
Eka Tarwaca Susila Putra
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Plant Growth ◽  
Leaf Area ◽  
Surface Area ◽  
Dry Weight ◽  
Root Surface ◽  
Black Pepper ◽  
Piper Nigrum ◽  
Root Surface Area

Abstract. Issukindarsyah, Sulistyaningsih E, Indradewa D, Putra ETS. 2020. The growth of three varieties of black pepper (Piper nigrum) under different light intensities related to indigenous hormones role. Biodiversitas 21: 1778-1785. Low light intensity causes the alteration of plant biochemical and morphological as the mechanism of adaptation. The experiment used split-plot design with three replications. The main plots were three light intensity levels, i.e. 100%, 75%, and 50% radiation; while subplots were three varieties namely Nyelungkup, Petaling 1 and Petaling 2. This research was conducted to figure out the effect of shadings on hormones and the growth of three varieties of black pepper (Piper nigrum L.). The results showed that in initial vegetative growth, varieties of Nyelungkup and Petaling 1 had higher growth of both ortotroph and plagiotroph branches, leaf number, leaf area, length of root, root surface area, plant dry weight, nett assimilation rate, and plant growth rate than the variety of Petaling 2. The light intensity of 50% and 75% increased the auxin and gibberellin contents of the leaf but they did not affect the zeatin. The maximum gibberellin and auxin contents of leaf were recorded at 75% light intensity. The 50% and 75% light intensity raised the length, diameter, and internode of ortotroph branch; number, length, and internode of plagiotroph branch; leaf number; leaf area; leaf area ratio; length of root; root surface area; plant growth rate and plant dry weight related to indigenous hormones role.

scholarly journals Stomatal opening and growth in tomato seedlings treated with different proportions of red and blue light

2019 ◽  
Vol 99 (5) ◽  
pp. 688-700 ◽  
Author(s):  
Junwei Yang ◽  
Tingting Liang ◽  
Lu Liu ◽  
Tonghua Pan ◽  
Zhirong Zou
Keyword(s):  
Blue Light ◽  
Light Quality ◽  
Red Light ◽  
Chloroplast Ultrastructure ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Stomatal Opening ◽  
Detailed Knowledge ◽  
Tomato Seedlings

Stomatal opening/closure plays a key role in balancing a plant’s need to conserve water, while still allowing for the exchange of photosynthetic and respiratory gasses with the atmosphere. Stomatal opening/closure can be induced by differences in light quality but a detailed knowledge of the role of light in stomatal regulation in tomato is limited. In this study, we evaluated red and blue light-dependent stomatal opening processes in tomato seedlings and explored the mechanisms involved using different light-quality treatments. After 10 h of darkness, tomato seedlings were subjected to the following five treatments: monochromatic red light (R), 33% blue (2R1B), 50% blue (1R1B), 67% blue (1R2B), and monochromatic blue light (B) at 200 μmol m−2s−1light intensity. The highest stomatal conductance recorded were for 1R1B. Stomatal aperture under 1R1B showed a 92.8% increase after 15 min and a 28.6% increase after 30 min compared with under R alone. Meanwhile, the study shows that the expressions of the plasma membrane H+-ATPase in the leaf were regulated by different proportions of blue light. The results show that the expressions of HA1 and HA4 increased under 1R1B and 1R2B after 15 min of exposure compared with under R alone. Under 1R1B, our results also show net photosynthesis increased compared with R and B after longer treatments, which may be related to chloroplast ultrastructure, and leaf dry weight increased compared with under 1R2B or B alone, but there were no differences under the R and 2R1B light treatments.

Effects of micro-environmental factors on the photoautotrophic growth of Hibiscus sagittifolius Kurz cultured in vitro

2018 ◽  
Vol 39 (4) ◽  
pp. 496-506 ◽  
Author(s):  
Nguyen Thuy Phuong Duyen ◽  
Tran Thi Van ◽  
Nguyen Thu Le Minh ◽  
Nguyen Thi Quynh
Keyword(s):  
Environmental Factors ◽  
Light Intensity ◽  
Leaf Area ◽  
Dark Period ◽  
Dry Weight ◽  
Fresh Weight ◽  
Photoautotrophic Growth ◽  
Temperature Regimes ◽  
Folk Remedy

The arrow leaf abelmoschus rhizome (Hibiscus sagittifolius Kurz), or Sam Bo Chinhin Vietnamese, is a perennial suffrutex herb from which the tuber root is used as a medicine in folk remedy. This species is widely distributed and can be found on many terrains across South East Asia. With an aim to create a large number of uniform and high-quality H. sagittifolius transplants in vitro, effects of some environmental factors such as photoperiod and temperature on the photoautotrophic growth of H. sagittifoliusin vitro plants were investigated. In vitro single nodal cuttings, each with an unfolded leaf, were cultured photoautotrophically (without sucrose and vitamins) on mineral SH medium, under light intensity of 150 µmol m-2 s-1, temperature of 24oC ± 2oC, relative humidity (RH) of 55% ± 5% and three different photoperiods (8, 12 or 16 h d-1) in the first experiment. Commercial polypropylene bags (V = 1,000 ml), attached with two filter-paper membranes, were used as culture vessels. After 42 days of culture, H. sagittifolius plants under the photoperiod of 16 h d-1 had the greatestincreased fresh weight (502.3 mg/plt), increased dry weight (39.5 mg/plt) and leaf area (17.0 cm2) than those put under 8 hd-1or 12 h d-1. In addition, H. sagittifolius plants also showed statistical differences in growth when photoautotrophically cultured in different air temperature regimes, including 28/25oC (photo-/dark period), 25/25oC and 20/25oC. Increased fresh weight (775 mg/plt), increased dry weight (62 mg/plt) and leaf area (22.7 cm2) of in vitro H. sagittifolius plants were the greatest when temperature was maintained at 28 oC during photoperiod. On the contrary, the photoperiod temperature of 20oC resulted in the shortest shoot length and root length of H. sagittifoliusplants. In conclusion, this study proved that H. sagittifolius plants had the best growth when cultured on SH medium, without sucrose and vitamins supplementation, under light intensity of 150 µmol m-2 s-1, RH 55% ± 5%, photoperiod of 16 h d-1, temperature regime of 28/25oC(photo-/dark period). Citation: Nguyen Thuy Phuong Duyen, Tran Thi Van, Nguyen Le Thu Minh, Nguyen Thi Quynh, 2017. Effects of micro-environmental factors on the photoautotrophic growth of Hibiscus sagittifolius Kurz cultured in vitro. Tap chi Sinh hoc, 39(4): 496-506. DOI: 10.15625/0866-7160/v39n4.11030. *Corresponding author: [email protected] 7 September 2017, accepted 15 December 2017

Early seedling growth and forage production of diploid and tetraploid crested wheatgrass and Russian wildrye cultivars

2008 ◽  
Vol 88 (4) ◽  
pp. 687-693 ◽  
Author(s):  
Paul G Jefferson ◽  
Bruce Coulman
Keyword(s):  
Seedling Growth ◽  
Field Trial ◽  
Seedling Emergence ◽  
Field Trials ◽  
Tiller Number ◽  
The Other ◽  
Forage Production ◽  
Seedling Vigour ◽  
Crested Wheatgrass ◽  
Russian Wildrye

Cultivars selected for improved seedling vigour may also differ in seedling growth and subsequent forage production. The objective of this project was to compare three cultivars of crested wheatgrass (CWG) and four cultivars of Russian wildrye (RWR) for seedling growth in a greenhouse (GH) trial and two field trials when seeded at 15, 30 and 45 mm depths. Cultivars were Goliath, Kirk and Parkway CWG and SCR39903, Swift, Tetracan, and Tom RWR. Seedling emergence, tiller number, and seedling biomass were determined at 28 d after seeding (DAS) in all three trials. In addition, forage dry matter (DM) yield was determined for 2 yr in the field trials. Small-seeded diploid Parkway crested wheatgrass had reduced emergence at 45 mm seeding depth compared with larger-seeded tetraploid Kirk and Goliath. Goliath had reduced tillering compared with the other two CWG cultivars. The emergence of Tetracan tetraploid RWR was greater at deeper seeding depth than diploid cultivars, SCR39902, Swift and Tom in Field Trial 2, but not in Field Trial 1 and the GH trial. Seedling tiller number of Tetracan RWR was less than that of the other three cultivars. Two-year total CWG forage DM yield in the field was best correlated to emergence. In contrast, 2-yr total RWR forage DM was best correlated to seedling tiller number in GH and Field Trial 2 despite the low tiller numbers at 28 d after seeding. Field emergence of Russian wildrye did not appear to be limiting to seedling establishment in contrast to previous reports. Selection in RWR should include seedling tiller number in combination with seedling emergence in order to improve both seedling vigour and forage productivity. Key words: Establishment, tiller, emergence, forage yields, seedling depth

scholarly journals Growth analysis in chard plants (Beta vulgaris L. Cicla, cv. 'Pencas Blancas') exposed to different light quality

2014 ◽  
Vol 32 (2) ◽  
pp. 205-212 ◽  
Author(s):  
Fánor Casierra-Posada ◽  
Esteban Zapata-Casierra ◽  
Daniel A. Chaparro-Chaparro
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Dry Matter ◽  
Light Quality ◽  
Dry Weight ◽  
Dry Mass ◽  
Dry Matter Partitioning ◽  
Absolute Growth ◽  
Net Assimilation ◽  
Total Dry Weight

To determine the effects of light quality on the growth indices of plants, Pencas Blancas cultivar chard plantlets were grown for 2 months under five different light treatments, obtained by filtering sunlight through colored polyethylene films. The treatments included: red, blue, green, yellow and transparent cover colors. A transparent cover (white light) was used as the control. The colored covers affected the plant growth. The plants grown under the yellow cover presented a better behavior with regards to growth, taken as: total dry weight per plant, leaf area, specific leaf area, absolute growth rate, relative growth rate, harvestable dry matter and root to shoot ratio. The dry matter partitioning in the leaves and roots was affected by the light quality, but not in the petioles, with a higher accumulation of dry mass in the leaves of plants grown under the yellow cover. As a consequence of the enhanced leaf area in the plants under the yellow cover, they also had the highest water uptake. On the other hand, the highest net assimilation rate value was found in plants grown under the transparent cover. These results open up the possibility of using yellow colored cover in leafy green vegetables, especially in chard plants grown under controlled conditions.

Red and far-red light influence carbon partitioning, growth and flowering of bahia grass (Paspalum notatum)

1995 ◽  
Vol 125 (3) ◽  
pp. 355-359 ◽  
Author(s):  
F. J. Marousky ◽  
F. Blondon
Keyword(s):  
Light Quality ◽  
Dark Period ◽  
Leaf Growth ◽  
Red Light ◽  
Dry Weight ◽  
Paspalum Notatum ◽  
Starch Accumulation ◽  
Long Day ◽  
Bahia Grass ◽  
Short Days

SUMMARYBahia grass (Paspalum notatum Flugge) plants were grown in growth chambers at Gif, France, and at Gainesville in Florida, demonstrating that the species is a long-day plant and greatly influenced by light quality during the photosynthetic period. Flowering occurred in all instances when the middle of the dark period was interrupted with red or red + far-red light. With nightly interruptions of farred light, flowering occurred only when a sufficient quantity of far-red was present during the photosynthetic period. Plants grown under short days with nightly interruptions of red, far-red or red + far-red light had less starch accumulation and greater leaf growth and dry weight than plants grown without nightly light interruptions, whatever the light quality during the photosynthetic period. The treatments did not affect the partitioning of assimilates and flowering in the same way.

scholarly journals PHOTOSELECTIVE SHADING COMPOUNDS REGULATE GROWTH OF HYPOESTES PHYLLOSTACHYA Bak.

HortScience ◽  
1994 ◽  
Vol 29 (7) ◽  
pp. 737c-737 ◽  
Author(s):  
Sven E. Svenson ◽  
Diane L. Johnston
Keyword(s):  
Leaf Area ◽  
Red Light ◽  
Dry Weight ◽  
Growth Responses ◽  
Shoot Dry Weight ◽  
Selective Control

`Pink Splash' Hyoestes were grown in chambers fitted with single-walled polycarbonate. Chambers were shaded with various photoselective shading compounds, using a white shading compound as a non-selective control. When grown under orange shading, plants had more shoot dry weight, greater leaf area, larger stem diameters, and were taller compared to plants shaded with white. When grown under green shading, plants had less shoot dry weight, less leaf area, smaller stem diameters, and were taller compared to plants shaded with white. Intermediate responses were recorded when plants were grown under red, blue or yellow shading. Differences in the ratio of red to far-red light among shading compounds did not provide a consistent explanation of growth responses.

scholarly journals Incident Irradiance and Cupric Hydroxide Container Treatment Effects on Early Growth and Development of Container-grown Pawpaw Seedlings

2002 ◽  
Vol 127 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Kirk W. Pomper ◽  
Desmond R. Layne ◽  
Snake C. Jones
Keyword(s):  
Leaf Area ◽  
Growth And Development ◽  
Red Light ◽  
Leaf Size ◽  
Dry Weight ◽  
Leaf Number ◽  
The North ◽  
Landscape Plant ◽  
Total Plant ◽  
Cupric Hydroxide

The North American pawpaw [Asimina triloba (L.) Dunal] has great potential as a fruit crop or as a landscape plant. The influence of incident irradiance on pawpaw seedling growth and development in containers was examined in the greenhouse and outdoors. Root spiraling can be a problem for container-grown pawpaw seedlings; therefore, the influence of paint containing cupric hydroxide [Cu(OH)2] at 100 g·L-1 applied to the interior of containers on plant growth was also examined in a greenhouse environment. In pawpaw seedlings grown outdoors for 11 weeks, low to moderate shading levels of 28%, 51%, or 81% increased leaf number, total leaf area, and total plant dry weight (DW) compared to nonshaded seedlings. A shading level of 81% decreased the root to shoot ratio by half compared to nonshaded plants. Shading of 98% reduced leaf number, leaf size, and shoot, root, and total plant DW. Shading increased leaf chlorophyll a and b concentrations for pawpaw seedlings grown outdoors, while it decreased average specific leaf DW (mg·cm-2). In a separate greenhouse experiment, pawpaw seedlings subjected to shade treatments of 0%, 33%, 56%, 81%, or 98% did not respond as greatly to shading as plants grown outdoors. Greenhouse-grown plants had greater total and average leaf area under 33% or 56% shading than nonshaded plants; however, shading >56% reduced root, shoot, and total plant DW. Total shoot DW was greater in greenhouse grown plants with 33% shading compared to nonshaded plants. Pawpaw seedlings in control and most shade treatments (33% to 81%) in the greenhouse environment had more leaves and greater leaf area, as well as larger shoot, root, and total plant DW than seedlings in similar treatments grown outdoors. The greenhouse environment had a 10% lower irradiance, a 60% lower ultraviolet irradiance, and a significantly higher (1.23 vs. 1.20) red to far-red light ratio than the outdoors environment. Treatment of container interiors with Cu(OH)2 decreased total and lateral root DW in nonshaded seedlings, and it adversely affected plant quality by causing a yellowing of leaves and reduction of chlorophyll levels by the end of the experiment in shaded plants. Growth characteristics of pawpaw seedlings were positively influenced by low to moderate shading (28% or 51%) outdoors and low shading (33%) in the greenhouse. Seedlings did not benefit from application of Cu(OH)2 to containers at the concentration used in this study. Commercial nurseries can further improve production of pawpaw seedlings using low to moderate shading outdoors.

scholarly journals CO2 enrichment and increasing light intensity till a threshold level, enhance growth and water use efficiency of lettuce plants in controlled environment

2020 ◽  
Vol 48 (4) ◽  
pp. 2244-2262
Author(s):  
Maryam ESMAILI ◽  
Sasan ALINIAEIFARD ◽  
Mahmoud MASHAL ◽  
Parisa GHORBANZADEH ◽  
Mehdi SEIF ◽  
...  
Keyword(s):  
Light Intensity ◽  
Water Use Efficiency ◽  
Leaf Area ◽  
Water Use ◽  
Dry Weight ◽  
Co2 Concentration ◽  
Photon Flux ◽  
Fresh Weight ◽  
Co2 Concentrations ◽  
Use Efficiency

Carbon dioxide (CO2) and light intensity are the two main environmental drivers known to play important roles in crop growth and yield. In the current study, lettuce seedlings were exposed to four different light intensities [(75, 150, 300 and 600 Photosynthetic Photon Flux Density (PPFD)] and four different concentrations of CO2 (400, 800, 1200 and 1600 ppm). By increasing light intensity and CO2 concentration growth parameters such as fresh weight, dry weight and leaf area were stepwise increased from 75 to 300 PPFD and from 400 ppm to 1200 ppm CO2 concentration. Maximum fresh weight was observed in 300 PPFD under both 1200 ppm and 1600 ppm CO2 concentrations. Highest dry weight was obtained in plants exposed to 300 and 600 PPFD under both 1200 and 1600 ppm CO2 concentrations. Highest leaf area was detected in 300 PPFD under both 1200 and 1600 ppm CO2 concentrations. Widest stomatal pore aperture was detected in 600 PPFD under 400 ppm and 800 ppm CO2 concentrations. Evapotranspiration increased in a light intensity and CO2 concentration-dependent manner; higher light intensity or higher CO2 concentration, more evapotranspiration. Highest water use efficiency (WUE) was achieved in plants exposed to 300 PPFD under 1200 ppm CO2 concentration. In conclusion, to achieve best growth performance and WUE, lettuce should be produced under 300 PPFD light intensity and 1200 ppm CO2.

Effects of Light Quality on the Life Cycles of Crabgrass and Barnyardgrass

Weed Science ◽  
1968 ◽  
Vol 16 (1) ◽  
pp. 58-60 ◽  
Author(s):  
Stuart Dunn ◽  
G. K. Gruendling ◽  
Aubrey S. Thomas
Keyword(s):  
Blue Light ◽  
Light Quality ◽  
Energy Levels ◽  
Red Light ◽  
Dry Weight ◽  
Life Cycles ◽  
Order Effects ◽  
Yellow Light ◽  
Digitaria Sanguinalis ◽  
Delayed Flowering

Large Crabgrass (Digitaria sanguinalis (L.) Scop.) and barnyardgrass (Echinochloa crusgalli (L.) Beauv.) plants were grown from seedlings to maturity under five light qualities of equal energy levels. For crabgrass, both fresh and dry weight yields of plant tops grown under red light and under cool white light were significantly greater than those under green, yellow, or blue light. Length of stem followed this same order. Effects of light quality on reproduction were not as consistent; green and blue light caused the largest numbers of seed heads to form, while yellow light delayed flowering and resulted in the least number and weight of seed heads. Somewhat similar responses to light were found with barnyardgrass plants, except that yields under yellow light were close to those under red light for this species. Blue light caused smallest plants in both kinds of weeds.

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