Effects of Density and Species Proportion on Competition between Spurred Anoda (Anoda cristata) and Velvetleaf (Abutilon theophrasti)

Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 351-357 ◽  
Author(s):  
David T. Patterson
Keyword(s):  
Leaf Area ◽  
Mixed Culture ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Shoot Biomass ◽  
Photon Flux Density ◽  
Regression Equations ◽  
Shoot Weight ◽  
Biomass Plant ◽  
The Impact

Spurred anoda and velvetleaf were grown for 40 days in controlled-environment chambers in monocultures at densities of 2, 4, 8, and 12 plants per 20-cm-diam pot and in mixed culture with all combinations of 2, 4, 8, and 12 plants of each species per pot. The day/night temperature was 29/23 C, and the photosynthetic photon flux density (PPFD) was 1000 μE m–2s–1. Shoot dry weights and leaf areas of the two species were similar when they were grown in monoculture. However, in mixed culture spurred anoda exceeded velvetleaf in leaf area/plant and shoot weight/plant in 15 out of 16 treatments. Multiple linear regression equations relating shoot biomass/plant to the density of both species in mixed culture were calculated. Comparison of competition coefficients from these equations indicated that the competitive impact of a single spurred anoda plant was equivalent to the impact of 2.5 velvetleaf plants. In mixed culture, spurred anoda always contributed a greater proportion of the total shoot weight and total leaf area per pot than would be predicted from its proportion of the total plant population. These results indicate spurred anoda is competitively superior to velvetleaf.

Response of Sonia roses to continuous daytime CO2 supplementation under controlled environment conditions

1988 ◽  
Vol 39 (5) ◽  
pp. 863 ◽  
Author(s):  
M Zeroni ◽  
J Gale
Keyword(s):  
Leaf Area ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Controlled Environment ◽  
Flower Bud ◽  
Flower Yield ◽  
Co2 Concentrations ◽  
Water Vapour Diffusion ◽  
Flower Quality

Rose plants (Rosa hybrida cv. Sonia, Syn. Sweet Promise) were placed in growth chambers under conditions resembling winter in a controlled environment greenhouse in the desert: mild temperatures, high incident photosynthetic photon flux density (PPFD), high air humidity and 10.5 h daylenght. Concentrations of CO2 in the air were maintained throughout the day at 320, 600 or 1200 8l l-1 with approximately 350 8l l-1 at night. Plant growth (length, fresh and gry weight), development (breaks, blindness), flower yield and flower quality (flower bud diameter, fresh weight and cane length) indices were monitored throughout three consecutive flowering cycles. CO2 supplementation caused an increase in leaf resistance to water vapour diffusion, accompanied by a reduction in the rate of transpiration per unit leaf area, Total leaf area increased at higher CO2 concentrations. Water use per plant did not change. Plant water potentials increased with rising CO2 concentrations. Growth, development, flower yield and flower quality were greatly enahnced in the CO2-enriched atmosphere. The response of growth and development to CO2 supplementation tended to decrease slightly with time when calculated per branch, but increased when calculated per plant. Flower yield and qualtiy did not change with time. The highest CO2 treatment resulted in a sustained, approximately 50% increase in yield, and doubling of the above quality indices throughout the three growth cycles.

Photon flux density dependence of carbon acquisition and demand in relation to shoot growth of kiwifruit (Actinidia deliciosa) vines grown in controlled environments

2001 ◽  
Vol 28 (2) ◽  
pp. 111 ◽  
Author(s):  
Dennis H. Greer
Keyword(s):  
Leaf Area ◽  
Shoot Growth ◽  
Actinidia Deliciosa ◽  
Stem Length ◽  
Photon Flux ◽  
Shoot Biomass ◽  
Photon Flux Density ◽  
Leaf Biomass ◽  
Respiration Rates ◽  
C Balance

Kiwifruit [Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson] vines were grown in four controlled photon flux densities (PFDs) from 250 to 1100 µmol m –2 s –1 for 130 d starting from pre-budbreak to measure relationships between shoot growth and carbon (C) demand and to assess the effect of PFD on these processes. Leaf area, stem length, photosynthesis and respiration rates were measured on the same leaves at regular intervals. From daily C acquisition and accumulation in biomass, the net C balance per cane was determined throughout the experiment. High-PFD-grown vines had 13% more leaf area, 250% more leaf biomass and 30% more stem biomass than low-PFD-grown vines. High-PFD-grown vines also partitioned relatively more biomass to photosynthetic tissue than to supporting stem tissue compared with low-PFD-grown vines. Rates of net photosynthesis were highest on vines grown at 800 µmol m –2 s –1 , but respiration rates were highest in high-PFD-grown vines. Vines grown at 1100 µmol m –2 s –1 had a net gain of 119 g sh –1 and 53 g sh – at 250 µmol m –2 s –1 , of which 46 and 58%, respectively, was used in shoot biomass growth. Net C balance was negative for 30 d after budbreak. Over 130 d, high-PFD-grown vines produced a total surplus of 64 g sh –1 , while low-PFD-grown vines produced 22 g sh –1 . Results demonstrate that irradiance has no effects on developmental processes but has marked effects on vegetative growth rates of kiwifruit vines. Underlining this, the C economy of these shoots is highly and quantitatively dependent on the PFD during growth.

scholarly journals The Impact of Carbon Dioxide Concentrations and Low to Adequate Photosynthetic Photon Flux Density on Growth, Physiology and Nutrient Use Efficiency of Juvenile Cacao Genotypes

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 397 ◽  
Author(s):  
Virupax C. Baligar ◽  
Marshall K. Elson ◽  
Alex-Alan F. Almeida ◽  
Quintino R. de Araujo ◽  
Dario Ahnert ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Leaf Area ◽  
Nutrient Use Efficiency ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Growth Physiology ◽  
Nutrient Use ◽  
Use Efficiency

Cacao (Theobroma cacao L.) was grown as an understory tree in agroforestry systems where it received inadequate to adequate levels of photosynthetic photon flux density (PPFD). As atmospheric carbon dioxide steadily increased, it was unclear what impact this would have on cacao growth and development at low PPFD. This research evaluated the effects of ambient and elevated levels carbon dioxide under inadequate to adequate levels of PPFD on growth, physiological and nutrient use efficiency traits of seven genetically contrasting juvenile cacao genotypes. Growth parameters (total and root dry weight, root length, stem height, leaf area, relative growth rate and net assimilation rates increased, and specific leaf area decreased significantly in response to increasing carbon dioxide and PPFD. Increasing carbon dioxide and PPFD levels significantly increased net photosynthesis and water-use efficiency traits but significantly reduced stomatal conductance and transpiration. With few exceptions, increasing carbon dioxide and PPFD reduced macro–micro nutrient concentrations but increased uptake, influx, transport and nutrient use efficiency in all cacao genotypes. Irrespective of levels of carbon dioxide and PPFD, intraspecific differences were observed for growth, physiology and nutrient use efficiency of cacao genotypes.

scholarly journals Timing of Stolon Removal Alters Daughter Plant Production and Quality in the Ever-bearing Strawberry ‘Albion’

HortScience ◽  
2021 ◽  
pp. 1-7
Author(s):  
Xiaonan Shi ◽  
Ricardo Hernández ◽  
Mark Hoffmann
Keyword(s):  
Day Treatment ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Plant Production ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Total Biomass ◽  
Cultural Methods ◽  
Mother Plants ◽  
The Impact

Commercial strawberry (Fragaria ×ananassa Duch.) plants propagate through the development of stolons (runners) with attached daughter plants. While it is known that temperature and photoperiod affect strawberry propagation, little knowledge exists on whether cultural methods may influence stolon and daughter plant development. The objective of this study was to characterize the impact of three stolon removal treatments on the development of daughter plants in the ever-bearing strawberry ‘Albion’. Treatments included 1) stolon removal every 7 days, nine times total; 2) stolon removal every 21 days, three times total; and 3) one-time stolon removal after 63 days. Strawberry plants were grown in a controlled environment (26 °C, 507 μmol⋅m–2⋅s–1 photosynthetic photon flux density, 14-hour photoperiod) in soilless media and fertilized with a customized nutrient solution. Mother plants in the 63-day treatment produced more daughter plants (102 per plant), than in the 21-day treatment (33 per plant) and the 7-day treatment (16 per plant). In the 63-day treatment, daughter plants and stolons accumulated to 86.6% of the total biomass, to 42.9% in the 7-day treatment and to 60.6% of total biomass in the 21-day treatment. Mother plant organs (including roots, crown, and leaves) had less dry weight in the 63-day treatment compared with the 7-day treatment and 21-day treatment, respectively. Furthermore, the daughter plants produced at the 63-day treatment had smaller crown diameters (0.65 cm) and less dry weight (0.51 g) and a higher number of fully expanded leaves (2.9) and visible roots (13.4) compared with the 21-day treatment and the 7-day treatment. The results of this study show daughter plant production of strawberry plants declines significantly with shorter stolon removal intervals, indicating the need to adjust stolon removal in strawberry nurseries for optimal daughter plant production.

THE EFFECT OF PHOTOSYNTHETIC PHOTON FLUX DENSITY ON CUCUMBER AND TOMATO TRANSPLANTS ASSIMILATIVE INDICES

2015 ◽  
Author(s):  
Aistė Bagdonavičienė ◽  
Aušra Brazaitytė ◽  
Julė Jankauskienė ◽  
Pavelas Duchovskis
Keyword(s):  
Solid State ◽  
Leaf Area ◽  
Weight Ratio ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Light Emitting ◽  
Net Assimilation ◽  
Positive Effect

The objective of our studies was to evaluate the assimilative indices of cucumber (‘Pasalimo F1’) and tomato (‘Marissa F1’) transplants, cultivated under various photosynthetic photon flux densities (PPFD) were provided by light-emitting diodes (LEDs). Experiment was performed in phytotron complex of Institute of Horticulture, LRCAF. A system of high-power, solid-state lighting modules with 92 % 638 nm (red) + 665 nm (red) + 731 nm (far red) and 8 % 447 nm (blue) was used in the experiments. The generated PPFD of each type of five solid-state modules was ~200 and ~400 μmol m-2 s-1. Our experiment revealed that increased net assimilation rate (NAR) depended on increased PPFD of cucumber and tomato hybrid. 400 μmol m-2 s-1 LED illumination had positive effect on relative growth rate (RGR). Cucumbers which were grown under 200 μmol m-2 s-1 had bigger leaf area ratio (LAR) and specific leaf area (SLA), their development has been bigger as compared to higher 400 μmol m-2 s-1 PPFD. High PPFD LED illumination had positive effect on leaf weight ratio (LWR), shoot root ratio (SRR) and tomato transplants development. These studies with various photosynthetic photon flux densities (PPFD) and LEDs light should be continued throughout plant vegetation.

Effect of Light, Watering Frequency, and Chlorsulfuron on Canada Thistle (Cirsium arvense)

Weed Science ◽  
1991 ◽  
Vol 39 (4) ◽  
pp. 590-594 ◽  
Author(s):  
Robert L. Zimdahl ◽  
Jingzhu Lin ◽  
Armando A. Dall'Armellina
Keyword(s):  
Leaf Area ◽  
Field Experiments ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Water Levels ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Canada Thistle ◽  
Root Dry Weight ◽  
Effect Of Light

Greenhouse and field experiments were conducted to determine effects of light, water, and chlorsulfuron on growth of Canada thistle. In the greenhouse, shoot and root dry weight, leaf area, and number of inflorescences decreased as light and water levels decreased. In the field, shoot and root dry weight, leaf area, and number of Canada thistle inflorescences were positively correlated with light intensity from 1832 to 30 μmol m−2s−1photosynthetic photon flux density (PPFD). The greatest effect of light was on inflorescence production which was eliminated at 30 μmol m−2s−1(PPFD). The combined effect of water stress and chlorsulfuron decreased root and shoot growth but did not eliminate it.

PLANT SPACING EFFECTS ON PHOTOSYNTHESIS AND TRANSPIRATION OF THE GREENHOUSE TOMATO

1988 ◽  
Vol 68 (4) ◽  
pp. 1209-1218 ◽  
Author(s):  
ATHANASIOS P. PAPADOPOULOS ◽  
DOUGLAS P. ORMROD
Keyword(s):  
Lycopersicon Esculentum ◽  
Leaf Area ◽  
Net Photosynthesis ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Plant Spacing ◽  
Greenhouse Tomato ◽  
Lycopersicon Esculentum Mill ◽  
Leaf Weight

The effect of four equidistant spacings (23, 30, 38, 45 cm) applied to four-row plantings of greenhouse tomato (Lycopersicon esculentum Mill. ’CR-6’) on plant net photosynthesis (P) and transpiration (E) was studied. Closer spacing decreased the leaf-area-based net photosynthesis (Pa) of the lower leaves but had little effect on the Pa of the upper leaves. The exposed parts of a tomato plant could adjust their Pa rates upwards to compensate for the low Pa of their shaded parts. The leaf-weight-based net photosynthesis (Pw) increased with the decrease of plant spacing and it was higher in inside compared to outside plants. The differences between the Pa and Pw results were mostly attributable to the effect of light in increasing the specific leaf weight (SLW). The E rate of plants increased at the closest spacing and there was a higher leaf weight based transpiration (Ew) in inside than outside plants. The leaf area based transpiration (Ea) and stomatal resistance (Rw) were not affected appreciably by light (photosynthetic photon flux density) other than at very low levels (i.e. less than 100 μmol m−2 s−1) where there was a sharp increase in Rw and a corresponding decrease in Ea. The P of plants growing in an environment of gradually declining duration and intensity of solar irradiance declined with the aging of plants. There was no similar effect on E.Key words: Lycopersicon esculentum Mill, plant spacing, photosynthesis, transpiration, tomato

scholarly journals Side Lighting Enhances Morphophysiology and Runner Formation by Upregulating Photosynthesis in Strawberry Grown in Controlled Environment

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Jingli Yang ◽  
Jinnan Song ◽  
Byoung-Ryong Jeong
Keyword(s):  
Growth Parameters ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Strawberry Plant ◽  
Light Emitting ◽  
Growth Environment ◽  
Closed Type ◽  
The Impact ◽  
Fine Tune

The significant effects of lighting on plants have been extensively investigated, but research has rarely studied the impact of different lighting directions for the strawberry plant. To understand the optimal lighting direction for better growth and development, this study investigated how strawberries respond to variations in the lighting direction to help fine-tune the growth environment for their development. We examined how the lighting direction affects plant morphophysiology by investigating plant growth parameters, leaf anatomy, epidermal cell elongation, stomatal properties, physiological characteristics, and expressions of runner induction-related genes (FaSOC1 and FaTFL1) and gibberellin (GA) biosyntheses-related genes (FaGA20ox2 and FaGA20ox4). In closed-type plant factory units, the rooted cuttings of strawberry (Fragaria × ananassa Duch.) ‘Suhlyang’ were subjected to a 10-h photoperiod with a 350 μmol∙m−2∙s−1 photosynthetic photon flux density (PPFD) provided by light-emitting diodes (LEDs) from three directions relative to the plants: top, side, and bottom. Our results demonstrated that the side lighting profoundly promoted not only morphophysiology, but also runner formation, by upregulating photosynthesis in strawberries. Side lighting can bring commercial benefits, which include reduced economic costs, easier controllability, and harmlessness to plants. This will help provide new insights for the propagation of the most commonly cultivated strawberries in South Korea.

scholarly journals Supplementary Light Source Affects the Growth and Development of Codonopsis lanceolata Seedlings

2018 ◽  
Vol 19 (10) ◽  
pp. 3074 ◽  
Author(s):  
Xiuxia Ren ◽  
Ya Liu ◽  
Hai Jeong ◽  
Byoung Jeong
Keyword(s):  
Light Source ◽  
Soluble Sugar ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Root Weight ◽  
Total Biomass ◽  
Codonopsis Lanceolata ◽  
Shoot Weight ◽  
Supplementary Lighting

Codonopsis lanceolata is widely used in traditional medicine and diets. However, there is no optimal protocol for the commercial production of C. lanceolata seedlings. This study was carried out to find the optimum supplementary light source for the production of C. lanceolata seedlings. Seedlings were grown for four weeks in a glasshouse with an average daily light intensity of 490 μmol·m−2·s−1 photosynthetic photon flux density (PPFD) coming from the sun and a 16-h daily supplementary lighting at 120 μmol·m−2·s−1 PPFD from either high-pressure sodium (HPS), metal halide (MH), far-red (FR), white LED (LED-w), or mixed (white: red: blue = 1:2:1) LEDs (LED-mix). The results showed that the greatest total biomass, stem diameter, ratio of shoot weight to shoot length, root biomass, and ratio of root weight to shoot weight were found in seedlings grown under supplementary LED-mix. Meanwhile, the stomatal properties and soluble sugar contents were improved for seedlings in LED-mix. The contents of starch, total phenols, and flavonoids were the greatest for seedlings in LED-w and LED-mix. The expression of photosynthetic proteins and genes in seedlings was also enhanced by LED-mix. Overall, these results suggest that LED-mix is advantageous to the photosynthetic potential and the accumulation of biomass, carbohydrates and secondary metabolites in C. lanceolata.

Effect of Light on Growth and Development of Field Bindweed (Convolvulus arvensis) and Russian Knapweed (Centaurea repens)

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 779-783 ◽  
Author(s):  
Armando A. Dall'Armellina ◽  
Robert L. Zimdahl
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Light Level ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Convolvulus Arvensis ◽  
Russian Knapweed ◽  
Reproductive Response ◽  
Field Bindweed

Field bindweed and Russian knapweed were grown from seed or rhizome segments under 520, 325, or 236 μmol·m–2· s–1photosynthetic photon flux density (PPFD) to determine vegetative and reproductive response. Flower production in both species declined with decreasing light level. Leaf area of field bindweed decreased as light level decreased, but Russian knapweed leaf area increased as light intensity decreased from 520 to 325 μmol·m–2·s–1PPFD or from 520 to 236 μmol·m–2·s–1. Dry matter of shoots, roots, and rhizomes of field bindweed grown from seed declined as light level decreased, but the only response of plants grown from rhizome segments was complete inhibition of rhizome production. Dry matter of Russian knapweed shoots and roots in plants grown from seed or rhizome segments decreased as light decreased. In both species the total PPFD was more important than whether low or high light level occurred first.

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