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.

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.

scholarly journals High Density and Uniform Plant Distribution Improve Soybean Yield by Regulating Population Uniformity and Canopy Light Interception

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1880
Author(s):  
Cailong Xu ◽  
Ruidong Li ◽  
Wenwen Song ◽  
Tingting Wu ◽  
Shi Sun ◽  
...  
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
Light Interception ◽  
Plant Distribution ◽  
Planting Density ◽  
Dry Matter Accumulation ◽  
Plant Spacing ◽  
Soybean Yield ◽  
The Relationship ◽  
Canopy Light Interception

Optimizing the spatial distribution of plants under normal conditions of water and fertilizer is widely used by farmers to improve soybean yield. However, the relationship between soybean yield and spatial plant distribution in the field has not been well studied. This study examined the effect of planting density and plant distribution pattern on soybean plant growth, yield components, canopy light interception, and dry matter accumulation. We also analyzed the relationship between photosynthetic rate, dry matter accumulation, and yield under different planting densities and plant distribution. A two year field experiment was conducted during the 2018 and 2019 soybean planting seasons. Two planting densities (1.8 × 105 and 2.7 × 105 plants ha−1) and two plant distribution patterns (uniform and non-uniform plant spacing) were tested. Higher planting density significantly increased the canopy light interception and dry matter accumulation during soybean growth, leading to increased soybean productivity. The seed yield of soybean under higher planting density was 22.8% higher than under normal planting density. Soybean planted under uniform spacing significantly reduced the differences plant-to-plant. Uniform plant spacing significantly increased the canopy light interception and dry matter accumulation of the soybean population. In addition, the coefficient of variation of seed weight per plant between individual plants under uniform plant distribution decreased by 71.5% compared with non-uniform plant distribution. Furthermore, uniform plant distribution increased soybean seed yield by 9.5% over non-uniform plant distribution. This study demonstrates that increasing planting density under uniform plant distribution can be useful to obtain higher seed yield without increasing other farm inputs.

A Test of a Model for Light Interception by Mixtures

1985 ◽  
Vol 12 (6) ◽  
pp. 681 ◽  
Author(s):  
GM Rimmington
Keyword(s):  
Optical Properties ◽  
Dry Matter ◽  
Light Interception ◽  
Light Energy ◽  
Dry Matter Production ◽  
Additional Test ◽  
Matter Production ◽  
Competition For Light

Predicted and observed data for the amount of light energy intercepted by mixtures of clover and ryegrass are compared, in an additional test of a model which relates competition for light to crop dry matter production. The closeness of predicted and observed values for light interception implies that the optical properties of the component species do not change significantly when they are grown in mixtures. If this is true, then it should be possible to predict the growth of mixtures using information about their optical properties when they are grown in monocultures.

scholarly journals Panicum maximum cv. Aries Establishment under Weed Interference with Levels of Light Interception and Nitrogen Fertilization

2019 ◽  
Vol 37 ◽  
Author(s):  
S. KRUCHELSKI ◽  
L.S. SZYMCZAK ◽  
L. DEISS ◽  
A. MORAES
Keyword(s):  
Nitrogen Fertilization ◽  
Dry Matter ◽  
Block Design ◽  
Interspecific Interaction ◽  
Light Interception ◽  
Panicum Maximum ◽  
Dry Matter Accumulation ◽  
Weed Interference ◽  
Randomized Block Design ◽  
Nitrogen Rates

ABSTRACT: The aim of this study was to evaluate the establishment of the pasture of Panicum maximum cv. Aries in an environmentally protected area under levels of interspecific interaction with the weed community. The experiment started after sowing P. maximum, and it was carried out in a randomized block design with four replications and the following factors: 3 light interception levels, 2 nitrogen rates, and 7 weekly sampling dates along pasture establishment (3x2x7). The light interception treatments, determined by photosynthetically active radiation, were given by mowing weeds over the canopy of P. maximum at 40% and 70% light interception, and no mowing (uncontrolled growth of weeds and P. maximum). Topdressing application of nitrogen in the form of urea was performed or not (0 or 200 kg N ha-1). The plant community was evaluated by number of species, dry matter accumulation, and density, and phytosociological indices were determined. The relative importance and dry matter accumulation of P. maximum were greater after nitrogen fertilization, which favored the species against weed competition. In contrast, there was lower weed density without nitrogen fertilization. Mowing weeds at 40% of light interception enabled P. maximum to accumulate more dry matter, while there was no difference between mowing weeds at 70% light interception and growing the forage crop freely with weeds. Reducing weed light interception as well as nitrogen fertilization, and consequently reducing the competitive ability of the weed, favored the establishment of P. maximum in diversified agro-ecosystems.

Density and row spacing effects on irrigated short wheats at low latitude

1976 ◽  
Vol 87 (1) ◽  
pp. 137-147 ◽  
Author(s):  
R. A. Fischer ◽  
I. Aguilar M. ◽  
R. Maurer O. ◽  
S. Rivas A.
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Light Interception ◽  
Dry Matter Production ◽  
Seeding Density ◽  
High Fertility ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Matter Production ◽  
Very High

SummaryDuring four winter seasons eight spacing and density experiments were made under irrigated high fertility conditions in north-west Mexico (latitude 27° N). Experiments included various Triticum aestivum and T. durum genotypes of spring habit, short stature derived from Norin 10 genes, and contrasting plant type. Measurements included dry-matter production, photosynthetic area index, and light interception during one experiment, total dry matter at maturity in most others and grain yield and its numerical components in all experiments.Grain yield and most other crop characters were unaffected by row spacings within the range 10–45 cm interrow width. The optimal seeding density for maximum grain yield was 40–100 kg/ha (80–200 plants/m2). Yield reductions at lower densities (20, 25 kg/ha) were slight and accompanied by reduced total dry-matter production. Yield reductions at higher densities (160–300 kg/ha) were also slight and were associated with more spikes/m2 but fewer grains/m2 and reduced harvest index. It is suggested that lower than normal preanthesis solar radiation or weather conditions leading to lodging can magnify these yield depressions at higher densities.Measurements showed rapid approach of crops to 95% light interception, reached even at a density of 50 kg/ha within 50 days of seeding. It is suggested that provided this occurs before the beginning of substantial dry-matter accumulation in the growing spikes (60 days after seeding) there will be no loss of grain yield with reduced seeding density. Results point to a ceiling photosynthetic area index for maximum crop growth rate although there was a tendency for rates to fall at very high indices (> 9). This tendency was associated with very high density, high maximum numbers of shoots, poor survival of shoots to give spikes (< 30%) and reduced number of grains/m3;. The relatively low optimal densities seen here may be characteristic of genotypes derived from Norin 10.Genotype × spacing, genotype × density and spacing × density interactions were generally non-significant and always small. There was a tendency for the presence of non-erect leaves or branched spikes to reduce the optimal density, but large differences in tillering capacity had no influence. Differences in lodging susceptibility can however lead to substantial genotype x density interactions.

scholarly journals How does structure matter? Comparison of canopy photosynthesis using one- and three-dimensional light models: a case study using greenhouse cucumber canopies

2021 ◽  
Author(s):  
Yi-Chen Pao ◽  
Katrin Kahlen ◽  
Tsu-Wei Chen ◽  
Dirk Wiechers ◽  
Hartmut Stützel
Keyword(s):  
Dry Matter ◽  
Empirical Relationship ◽  
Three Dimensional ◽  
Light Interception ◽  
Efficient Estimation ◽  
Light Extinction ◽  
Photosynthetic Parameters ◽  
Area Index ◽  
K Value ◽  
Greenhouse Cucumber

Abstract One-dimensional light models using the Beer-Lambert equation (BL) with the light extinction coefficient k are simple and robust tools for estimating light interception of homogeneous canopies. Functional-structural plant models (FSPMs) are powerful to capture light-plant interactions in heterogeneous canopies, but they are also more complex due to explicit descriptions of three-dimensional plant architecture and light models. For choosing an appropriate modelling approach, the trade-offs between simplicity and accuracy need to be considered when canopies with spatial heterogeneity are concerned. We compared two light modelling approaches, one following BL and another using ray tracing (RT), based on a framework of a dynamic FSPM of greenhouse cucumber. Resolutions of hourly-step (HS) and daily-step (DS) were applied to simulate light interception, leaf-level photosynthetic acclimation and plant-level dry matter production over growth periods of two to five weeks. Results showed that BL-HS was comparable to RT-HS in predicting shoot dry matter and photosynthetic parameters. The k used in the BL approach was simulated using an empirical relationship between k and leaf area index established with the assistance of RT, which showed variation up to 0.2 in k depending on canopy geometry under the same plant density. When a constant k value was used instead, a difference of 0.2 in k resulted in up to 27% loss in accuracy for shoot dry matter. These results suggested that, with the assistance of RT in k estimation, the simple approach BL-HS provided efficient estimation for long-term processes.

scholarly journals The Role of Deep Roots in Sorghum Yield Production under Drought Conditions

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 611
Author(s):  
Xiaofei Chen ◽  
Qi Wu ◽  
Yue Gao ◽  
Jiao Zhang ◽  
Yitao Wang ◽  
...  
Keyword(s):  
Crop Production ◽  
Dry Matter ◽  
Soluble Sugar ◽  
Photosynthetic Performance ◽  
Dry Matter Accumulation ◽  
Deep Roots ◽  
Filling Stage ◽  
Yield Production ◽  
Drought Conditions

Root function plays a vital role in maintaining crop production. However, the role of deep roots in yield production and their effects on photosynthetic performance in sorghum remain unclear. This study aimed to provide theoretical supports for establishing highly efficient root systems of sorghum to achieve more yield under certain conditions. In this study, two sorghum (Sorghum bicolor L. Moench) cultivars, Jiza127 and Jiza305, were cultivated in soil columns as experimental materials. Three treatments (no roots removed, CK; roots removed at 30 cm underground, R30; roots removed at 60 cm underground, R60) were carried out under drought conditions during the filling stage. The root bleeding intensity, endogenous substances in the root bleeding sap, photosynthetic characteristics, dry matter accumulation, and yield were measured. The results showed that R30 and R60 significantly reduced yield in both sorghum cultivars, and the effect of R30 on yield was greater than that of R60. The contributions of roots below 30 cm to the yield of both sorghum hybrids were notably higher than those below 60 cm. R30 significantly reduced the dry matter weights (DMWs) of leaves, stems, sheaths, and panicles. R60 significantly reduced the DMW of panicles but had no significant effect on the DMWs of leaves and stems. R30 significantly reduced the photosynthetic level and PSII reaction center activity; however, the effect of R60 was not significant. Although both R30 and R60 significantly reduced root activity and the soluble sugar, amino acid, gibberellin (GA3), and abscisic acid (ABA) contents of the root bleeding sap, some of the above indicators in R60 were significantly higher than those in R30 during the filling stage, indicating that the deeper roots (below 30 cm) had a critical regulatory effect on the physiological processes of the aerial parts in sorghum, which resulted in a stronger effect on yield, especially under drought conditions. In brief, the deep roots of sorghum played a key role in yield production, but the roots in different soil depths regulated yield production in different ways. Our results indicate that deep roots of sorghum deserve consideration as a potential trait for yield improvement especially under drought conditions.

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 Effect of weed control on weeds, grain yield and its components of maize (Zea mays L)

2020 ◽  
Vol 1 (1) ◽  
pp. 22-26
Author(s):  
Ola El-Badry ◽  
◽  
El-Sayed Gheith ◽  
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Weed Control ◽  
Dry Matter ◽  
Zea Mays L ◽  
Unit Area ◽  
Block Design ◽  
Research Station ◽  
Dry Matter Accumulation ◽  
Randomized Complete Block Design

The present study entitled “effect of weed control on weeds, grain yield and its components of maize (Zea mays L.) cv. Single cross-10 was carried out at the Agricultural and Experiments Research Station at Giza, Faculty of Agriculture, Cairo University, Egypt. The experiment was conducted in the summer 2017 and was repeated in 2018 on the same piece of land to conform previous findings. The experiment design was Randomized Complete Block design (RCBD) having three replications. Six treatments include atrazine (1.0 kg/ha), glyphosate (0.8 kg/ha). atrazine + glyphosate, one hand hoeing after three weeks, hand hoeing twice after three and five weeks from sowing and weedy chick as control were used. Results indicated that glyphosate was found superior to atrazine for all studied characters. Moreover, lower weed dry matter accumulation and higher weed control % as well as higher values of ear characters ( ear length, ear diameter, grain weight/ear and shilling %) and grain yield per unit area were recorded in tank mix application of atrazine + glyphosate followed by hand hoeing twice.

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