Growth of Amaranthus Hybridus (African Spinach) under diffferent Daylight Intensities in the Dry Season in Southern Nigeria

1987 ◽  
Vol 23 (2) ◽  
pp. 193-200 ◽  
Author(s):  
J. M. O. Eze
Keyword(s):  
Light Intensity ◽  
Biochemical Parameters ◽  
Dry Matter ◽  
Maximum Growth ◽  
Area Ratio ◽  
Dry Matter Accumulation ◽  
Amaranthus Hybridus ◽  
Maximum Accumulation ◽  
Southern Nigeria ◽  
Reduced Light

SummaryThe growth of Amaranthus hybridus under different daylight intensities was assessed in terms of physical, morphological and biochemical parameters. Maximum growth in many respects was achieved at about 70% of full daylight. However, full daylight favoured chlorophyll stability and maximum accumulation of total dry matter, carbohydrate, chlorophyll and ascorbic acid. The leaf area ratio increased uniformly with decrease in light intensity. Ageing was accelerated by full daylight. Reduced light intensity reduced dry matter accumulation in the roots more than in the stems or leaves.

Culture of Detached Ears of Wheat in Liquid Culture: Modification and Extension of the Method

1983 ◽  
Vol 10 (2) ◽  
pp. 227 ◽  
Author(s):  
BK Singh ◽  
CF Jenner
Keyword(s):  
Light Intensity ◽  
Liquid Medium ◽  
Dry Matter ◽  
Liquid Culture ◽  
Grain Filling ◽  
Prolonged Culture ◽  
Low Levels ◽  
Reduced Light ◽  
Days After Anthesis

The method of culturing detached ears of wheat in a liquid medium has been modified to provide for the culture of ears from anthesis to maturity. For prolonged culture of ears, the presence of the peduncular node was beneficial. Grains developing in ears cultured from 2 days after anthesis until they had ripened germinated normally. By comparison with ammonium or nitrate, glutamine was the better source of nitrogen particularly at low levels of sucrose in the medium; inorganic forms of nitrogen inhibited grain-filling. Setting of grains was apparently dependent upon the availability of carbohydrate and there was no evidence from treatments involving shading for a photomorphogenetic response to reduced light intensity. While grain-filling was sustained by the provision of sucrose supplied artificially, light did nevertheless affect the accumulation of dry matter in the grains.

The Effect of Reduced Light Intensity on Grass Weeds

Weed Science ◽  
2017 ◽  
Vol 65 (5) ◽  
pp. 603-613 ◽  
Author(s):  
Muhammad Yasin ◽  
Eva Rosenqvist ◽  
Christian Andreasen
Keyword(s):  
Light Intensity ◽  
Plant Height ◽  
Dry Matter ◽  
Photochemical Efficiency ◽  
Grass Species ◽  
Weed Species ◽  
Annual Bluegrass ◽  
Light Levels ◽  
Number Of Leaves ◽  
Reduced Light

The effect of reduced light intensity on the growth and development of three common grass weeds, blackgrass, silky windgrass, and annual bluegrass, was studied. Two identical greenhouse experiments displaced in time were performed with six light levels aiming at 0%, 20%, 50%, 80%, 90%, and 95% shade corresponding to a mean daily light integral (DLI) of 12.4, 9.63, 7.13, 2.74, 0.95, and 0.69 mol m−2d−1in experiment 1 and 21.2, 18.0, 10.7, 3.71, 1.64, 1.20 mol m−2d−1in experiment 2. Climate screens of acrylic fabric were used to create the light levels. A DLI of 0.69 to 3.71 mol m−2d−1substantially reduced the plant height, the number of leaves, leaf chlorophyll content index, stomatal conductance, maximum photochemical efficiency of photosystem II, and dry matter of blackgrass. It also reduced plant height, the number of leaves, and dry matter and delayed flowering of windgrass and annual bluegrass. Annual bluegrass reacted most rapidly when light levels increased from the lowest levels by producing more leaves. DLI thresholds for blooming were estimated to be about 7.13 mol m−2d−1for windgrass and 1.64 mol m−2d−1for annual bluegrass. Annual bluegrass was able to bloom and sustain biomass even at a DLI of 1.64 mol m−2d−1. This ability may contribute to an explanation of why annual bluegrass is among the most common weed species in highly competitive and well-fertilized crops even though it is much smaller than the two other grass species.

STUDIES ON THE BIOLOGY OF WILD OATS. II. GROWTH.

1977 ◽  
Vol 57 (3) ◽  
pp. 811-817 ◽  
Author(s):  
M. P. SHARMA ◽  
W. H. VANDEN BORN ◽  
D. K. MCBEATH
Keyword(s):  
Soil Moisture ◽  
Light Intensity ◽  
Soil Ph ◽  
Dry Matter ◽  
Field Capacity ◽  
High Light Intensity ◽  
Dry Matter Accumulation ◽  
Initial Growth ◽  
Nitrogen And Phosphorus ◽  
Wild Oats

Dry matter accumulation by wild oats (Avena fatua L.) in a growth cabinet, after an initial lag period, took place rapidly until 8 wk after emergence. Plant height and the number of leaves per plant increased at a nearly linear rate until 6 wk after emergence. Tillering occurred mainly during the period 2–4 wk after emergence. Low light intensity and short photoperiod severely restricted growth, and delayed heading and maturity. Plants grew best at day–night temperatures of 20–12 C, though initial growth was faster at higher temperature (28–20 C). In a black loam soil, plants responded to added nitrogen and phosphorus only under high light intensity. Both soil moisture and soil pH greatly influenced the growth of wild oats. Greatest dry matter accumulation was attained when soil pH was 7.5 or 8.5 and soil moisture was maintained above 75% field capacity. Hull color of the seed had no effect on the growth of wild oat plants. Plants produced from large seeds had higher dry weights than plants produced from small seeds. Implications of these findings for the control of wild oats are discussed.

scholarly journals ROOT RESTRICTION AND SHADING EFFECTS ON SUMMER SQUASH

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 591c-591
Author(s):  
D. Scott NeSmith
Keyword(s):  
Leaf Area ◽  
Dry Matter ◽  
Light Level ◽  
Dry Matter Accumulation ◽  
Light Conditions ◽  
Matter Production ◽  
Summer Squash ◽  
Shading Effects ◽  
Root Restriction ◽  
Reduced Light

Summer squash (Cucurbita pepo L.) was grown under greenhouse conditions in 0.35, 2.00, or 7.60 liter containers with full light or with 50% full light to determine the effects of root restriction and reduced light on crop growth and development. Leaf area was determined nondestructively over the course of the experiment, and destructive plant samples were taken weekly to determine dry matter accumulation and partitioning. The experiment was repeated to validate results. There was a decline in production of plant leaf area and dry matter accumulation in response to increased root restriction under full light conditions. However, under 50% light, root restriction had less impact on plant growth when comparing the 2.00 and 7.60 liter container plants. Under the most severe root restricting conditions, light level had little impact on leaf area production and dry matter accumulation. There were no consistent differences in leaf chlorophyll attributable to root restriction or reduced light; however, there was a trend for decreased leaf weight per unit of leaf area under low light conditions. Fruit dry matter production was notably diminished under severe root restriction in full light, and under all root environments under 50% light.

scholarly journals Optimal Utilization of Light Energy in Semiclosed Greenhouse Using Three-Dimensional Cucumber Model

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Tingting Qian ◽  
Xiuguo Zheng ◽  
Juan Yang ◽  
Yeying Xu ◽  
Yan Wang ◽  
...  
Keyword(s):  
Light Intensity ◽  
Dry Matter ◽  
Unit Area ◽  
Three Dimensional ◽  
Light Interception ◽  
Parametric Modeling ◽  
Light Energy ◽  
Dry Matter Accumulation ◽  
Yield Production ◽  
Cucumber Yield

In the east of China, low temperature and light energy in winter are the main factors for the decline in cucumber yield, as well as in greenhouses without supplementary light. Optimal utilization of light energy is critical to increase cucumber yield. In this study, experimental measurements were conducted in two scenarios, April to May (Apr-May) and November to December (Nov-Dec) 2015, respectively, to analyze leaf development, dry matter accumulation, and yield of cultivated cucumber. Statistical analysis showed that leaves grew in Nov-Dec had larger leaf area and lower dry matter than leaves grew in Apr-May. This revealed that the dry matter accumulation rate per unit area was lower in winter. To be precise, the yield 0.174 kg/m2 per day in Nov-Dec was 35.3% lower than the yield in Apr-May. Environmental monitoring data showed that there was no significant difference in the average temperature between two scenarios, but the light intensity in Nov-Dec was only 2/3 of that in Apr-May. Three-dimensional (3D) cucumber canopy models were used in this study to quantify the effects of weak light on dry matter production in Nov-Dec. Three 3D canopies of cucumber were reconstructed with 20, 25, and 30 leaves per plant, respectively, by using a parametric modeling method. Light interception of three canopies from 8:00 to 15:00 on 4 November 2015 was simulated by using the radiosity-graphic combined model (RGM) with an hourly time step. CO2 assimilation per unit area was calculated using the FvCB photosynthetic model. As a result, the effects of light intensity and CO2 concentration on the photosynthetic rate were considered. The leaf photosynthesis simulation result showed that during the daytime in winter, the RuBP regeneration-limited assimilation Aj was always less than the Rubisco-limited assimilation Ac. This means that the limiting factor affecting the photosynthesis rate in winter was rather light intensity. As the CO2 concentration in the greenhouse was utmost in the morning, increasing the light intensity and therefrom increasing the canopy light interception at this time will be highly beneficial to increase the yield production. Through a comparative analysis of photosynthetic characteristics in these three virtual 3D canopies, the 25-leaf canopy was the best-performed canopy structure in photosynthetic production in winter. This study provides an insight into the light deficiency for yield production in winter and a solution to make optimal use of light in the greenhouse.

scholarly journals Effect of Different Integrated Management Practices on Growth of Different Wheat Genotypes

2021 ◽  
Vol 9 (3) ◽  
pp. 224-229
Author(s):  
Mohinder Singh ◽  
Keyword(s):  
Dry Matter ◽  
Management Practices ◽  
Nutrient Management ◽  
Growth Parameters ◽  
Integrated Management ◽  
Block Design ◽  
Maximum Growth ◽  
Dry Matter Accumulation ◽  
Integrated Nutrient Management ◽  
Rabi Season

An experiment was conducted during Rabi season of 2019-20 at Research Farm of the Faculty of Agricultural Sciences, SGT University Gurugram. The experiment was laid out in split block design with four varieties WH 283, RAJ 3765, WH 1105, NABI Black Wheat and six integrated nutrient management treatments viz. T1: 100 % RDF (150 kg N + 60 kg P + 25 kg ZnSo4 ha-1), T2: 90% RDF+10% Bio-Fertilizer (Rhizobium + PSB), T3: 80% RDF+ 10% (VC) + 10% Bio-fertilizer (Rhizobium + PSB), T4: 70% RDF+ 20 % (VC) + 10% Bio-fertilizer (Rhizobium + PSB), T5: 60 % RDF+ 30 % (VC) + 10% Bio-fertilizer (Rhizobium + PSB) and T6: Control. The highest growth parameters were recorded with WH 1105 followed by WH 283 and Raj 3765. The lowest growth parameters were recorded with NB black. The treatments were replicated thrice. The maximum growth parameters viz., plant height (93.8 cm), numbers of tillers in running meter (81.4) and dry matter accumulation (982.2g) per square meter were recorded with the application of 100% RDF and minimum at T6 at maturity.

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