Effects of the vertical distribution of a root-feeding insect (Anomala cuprea) on the yield, mortality, and size structure of Lolium perenne populations at different plant densities

Botany ◽  
2017 ◽  
Vol 95 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Tomonori Tsunoda ◽  
Naoki Kachi ◽  
Jun-Ichirou Suzuki
Keyword(s):  
Standard Deviation ◽  
Vertical Distribution ◽  
Lolium Perenne ◽  
Plant Density ◽  
Soil Layer ◽  
Individual Plant ◽  
Anomala Cuprea ◽  
High Plant Density ◽  
Plant Densities ◽  
The Vertical Distribution

The vertical distribution of belowground herbivores plays an important role in determining the performance of an individual plant, but we still do not know the effects of this distribution on plant populations. A grass (Lolium perenne L.) was, therefore, grown at two densities with three vertical distributions of the belowground herbivore Anomala cuprea Hope (Coleoptera: Scarabaeidae). The population yield decreased significantly in the treatments with a herbivore, and decreased most when the herbivore was in the top feeding zone (i.e., the shallowest soil). Plants only died when the herbivore was in the top zone or was free to move within the pot. At low plant density, the biomass of the three largest shoots decreased significantly in the presence of a herbivore, but that of shoots in the fourth and smaller ranks did not. At high plant density, shoot biomass was not significantly affected by herbivory, irrespective of plant size. The standard deviation of shoot size was larger at low densities than at high densities. At low, but not high plant densities, the standard deviation decreased when herbivory occurred in the shallowest soil layer. To our knowledge, this study is the first to demonstrate that the vertical distribution of a belowground herbivore can markedly affect the size dynamics of a plant population.

scholarly journals Effects of Ornamental Plant Density and Mineral/Plastic Media on the Removal of Domestic Wastewater Pollutants by Home Wetlands Technology

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5273
Author(s):  
Luis Carlos Sandoval-Herazo ◽  
Alejandro Alvarado-Lassman ◽  
María Cristina López-Méndez ◽  
Albino Martínez-Sibaja ◽  
Alberto A. Aguilar-Lasserre ◽  
...  
Keyword(s):  
Rural Areas ◽  
Plant Density ◽  
Ornamental Plants ◽  
Domestic Wastewater ◽  
High Density ◽  
High Plant Density ◽  
Plant Densities ◽  
Optimal Material ◽  
Planting Distance ◽  
Wastewater Pollutants

Wastewater treatment (WWT) is a priority around the world; conventional treatments are not widely used in rural areas owing to the high operating and maintenance costs. In Mexico, for instance, only 40% of wastewater is treated. One sustainable option for WWT is through the use of constructed wetlands (CWs) technology, which may remove pollutants using cells filled with porous material and vegetation that works as a natural filter. Knowing the optimal material and density of plants used per square meter in CWs would allow improving their WWT effect. In this study, the effect of material media (plastic/mineral) and plant density on the removal of organic/inorganic pollutants was evaluated. Low (three plants), medium (six plants) and high (nine plants) densities were compared in a surface area of 0.3 m2 of ornamental plants (Alpinia purpurata, Canna hybrids and Hedychium coronarium) used in polycultures at the mesocosm level of household wetlands, planted on the two different substrates. Regarding the removal of contaminants, no significant differences were found between substrates (p ≥ 0.05), indicating the use of plastic residues (reusable) is an economical option compared to typical mineral materials. However, differences (p = 0.001) in removal of pollutants were found between different plant densities. For both substrates, the high density planted CWs were able to remove COD in a range of 86–90%, PO4-P 22–33%, NH4-N in 84–90%, NO3-N 25–28% and NO2-N 38–42%. At medium density, removals of 79–81%, 26–32, 80–82%, 24–26%, and 39–41%, were observed, whereas in CWs with low density, the detected removals were 65–68%, 20–26%, 79–80%, 24–26% and 31–40%, respectively. These results revealed that higher COD and ammonia were removed at high plant density than at medium or low densities. Other pollutants were removed similarly in all plant densities (22–42%), indicating the necessity of hybrid CWs to increase the elimination of PO4-P, NO3-N and NO2-N. Moreover, high density favored 10 to 20% more the removal of pollutants than other plant densities. In addition, in cells with high density of plants and smaller planting distance, the development of new plant shoots was limited. Thus, it is suggested that the appropriate distance for this type of polyculture plants should be from 40 to 50 cm in expansion to real-scale systems in order to take advantage of the harvesting of species in these and allow species of greater foliage, favoring its growth and new shoots with the appropriate distance to compensate, in the short time, the removal of nutrients.

Effect of density on growth, development, yield and quality of kabocha (Cucurbita maxima)

1998 ◽  
Vol 38 (2) ◽  
pp. 195
Author(s):  
T. Botwright ◽  
N. Mendham ◽  
B. Chung
Keyword(s):  
Vegetative Growth ◽  
Plant Density ◽  
Total Yield ◽  
Cucurbita Maxima ◽  
Marketable Yield ◽  
Yield And Quality ◽  
High Plant Density ◽  
Plant Densities ◽  
Growth Development

Summary. The effect of plant density on growth, development, yield and quality of kabocha (buttercup squash) (Cucurbita maxima) was examined during 1992–93, at a field site in Cambridge, Tasmania. Plant densities ranged between 0.5 and 4.7 plants/m2. Marketable and total yields were fitted to a yield–density model. Total yield followed an asymptotic trend, approaching 33 t/ha at 4.7 plants/m2, while marketable yield had a parabolic relationship with density. Marketable yield increased to a maximum of 18 t/ha at 1.1 plants/m2, while declining at higher densities because of increased numbers of undersized fruit. Yield of vine marked and callused fruit did not vary with density, but represented a significant proportion of the total yield at all densities. High plant density reduced vegetative growth per plant due to competition for limited resources; as shown by decreased leaf area, number and length of vines, and plant dry weight. Yield tended to decline at high densities because of fewer female flowers and increased fruit abortion per plant. Plants at low densities had more vegetative growth but decreased yields, as increased abortion of fruit relative to the higher plant densities left only 1–2 large fruit per plant. Economic returns varied with plant density. At high densities, variable costs increased (particularly due to high seed cost) while gross income declined reflecting the relationship between marketable yield and plant density. The gross margin therefore declined at high densities.

scholarly journals Marginal superiority of maize: an indicator for density tolerance under high plant density

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Guangzhou Liu ◽  
Wanmao Liu ◽  
Yunshan Yang ◽  
Xiaoxia Guo ◽  
Guoqiang Zhang ◽  
...  
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Plant Density ◽  
Significant Negative Correlation ◽  
Growth Conditions ◽  
High Density ◽  
Leaf Angle ◽  
Individual Plant ◽  
High Plant Density ◽  
Tolerance Field

Abstract Marginal superiority is a common phenomenon in crops, and is caused by the competitiveness of individual plant for resources and crop adaptability to crowded growth conditions. In this study, in order to clarify the response of marginal superiority to maize morphology and plant-density tolerance, field experiments without water and nutrition stress were conducted at Qitai Farm in Xinjiang, China, in 2013–2014 and 2016–2019. The results showed that no more than three border rows of all the cultivars had marginal superiority under high density, about 90% of all the cultivars had no more than two border row that had marginal superiority and a significant negative correlation was observed between marginal superiority and population grain yield (first border row: y = − 2.193x + 213.9, p < 0.05; second border row: y = − 2.076x + 159.2, p < 0.01). Additionally, marginal superiority was found to have a significant positive relationship with plant density (first border row: y = 6.049x + 73.76, p < 0.01; second border row: y = 1.88x + 95.41, p < 0.05) and the average leaf angle above the ear (first border row: y = 2.306x + 103.1, p < 0.01). These results indicated that the smaller the leaf angle above the ear, the weaker the marginal superiority and the higher the grain yield. It suggests that the magnitude of marginal superiority in the border rows can be an indicator for plant-density tolerance under high density. What’s more, cultivars with small leaf angle above the ear can be selected to weaken the marginal superiority and improve grain yield under high plant density. Conversely, cultivars with a large leaf angle above the ear can be selected to achieve higher individual yield in intercropping systems with no more than four rows alternated with other crops.

The effect of plant density on populations of the cabbage root fly (Erioischia brassicae (Bch.)) and the cabbage stem weevil (Ceutorhynchus quadridens (Panz.)) on cauliflowers

1976 ◽  
Vol 66 (1) ◽  
pp. 113-123 ◽  
Author(s):  
S. Finch ◽  
G. Skinner
Keyword(s):  
Plant Density ◽  
Unit Area ◽  
Individual Plant ◽  
Cabbage Root Fly ◽  
Plant Densities ◽  
Equivalent Area ◽  
Concentric Circles ◽  
The Absolute ◽  
Absolute Population

AbstractTo study the effects of plant density on populations of the cabbage root fly (Erioischia brassicae (Bch.) ) and the cabbage stem weevil (Ceutorhynchus quadridens (Panz.)), cauliflowers were planted in 24 concentric circles to achieve spacings of 10–90 cm at 22 plant densities (1·5–83/m2). Some plants were treated with a root drench of chlorfenvinphos. Each week female cabbage root flies laid approximately three times as many eggs per individual plant at the lowest than at the highest plant densities tested. This was equivalent to approximately 350 and 5000 eggs/m2, respectively. The numbers of cabbage root fly pupae produced ranged from 11/m2 at the lowest to 210/m2 at the highest plant density. In the absence of an insecticide, increasing the plant density considerably increased the absolute population of the pest without affecting cauliflower yield. Approximately seven times as many flies were produced per unit area of untreated mini-cauliflowers as from an equivalent area of plants growing at a conventional density. When chlorfenvinphos was not applied, damage by the cabbage stem weevil occurred in 30% and 70% of the plants grown at the lowest and highest densities, respectively.

scholarly journals EFFECT OF SPRAYING WITH DIFFERENT CONCENTRATION OF LICORICE EXTRACT AND PLANT DENSITIES IN GROWTH AND YIELD OF SORGHUM BICOLOR L.

2019 ◽  
Vol 50 (6) ◽  
Author(s):  
Al-Mohmadi & Al-Ani
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Foliar Application ◽  
Growth And Yield ◽  
Control Treatment ◽  
Spring Season ◽  
Area Index ◽  
Fall Season ◽  
High Plant Density ◽  
Plant Densities

A field experiment was condueted at the experimental Farm, College of Agriculture University of AL-Anbar in replace location (Abu-Gheaib) in spring season of 2017. While in Fall season it was applied at AL-saqluwiya-Anbar Province 10 km west north of Falluga city to study the effect of four levels of licorice extractor (Glycyrrhiza glabra L.) (0,2,4 and 6) g.L-1 water and three (53,333, 66,666 and 88,888 plant) plant.ha-1. On growth and grain yield of Sorghum cv. Rabih. The experiment was applied using R.C.B.D. arranged in split plots with three replications. levels of plant densities were used as main-plot, while licorice extractor were used as sub-plot. Foliar application of licorice extractor was applied during vegetative growth. The results showed that, high plant density (88888) plant.h-1 significantly increase plant height and leaf area index, while most of traits were not significantly influenced by plant density including grain yield. Results revealed that foliar application of licorice extractor with 2,4,6 g.L-1 of water significantly influenced grain yield in spring season compane with control treatment and it is amounted to (9.62, 9.55 and 9.78) t.h-1 respectively. There were significant interaction between Licorice extractor and plant density in spring and fall season in grain yield. The higher grain yield of 10.31 and 10.33 t.h-1 were obtained when sorghum plants were sowing at hight density and sprayed with Licorice extractor at level          4 g.L-1 respectively

scholarly journals Comparison of Growth Indices of Nigella sativa L. under Different Plant Densities and Fertilization

2019 ◽  
pp. 231
Author(s):  
Ioannis Roussis, Ioanna Kakabouki, Dimitrios Bilalis
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Plant Density ◽  
Nigella Sativa ◽  
Crop Growth ◽  
Growth And Yield ◽  
Growth Indices ◽  
Area Index ◽  
High Plant Density ◽  
Plant Densities

Agronomic practices such as plant density and fertilizer management are referred to comprise crop environment, which influences plant growth, productivity, and ultimately the yield. The objective of the current study was to evaluate the influence of plant density and fertilization on the growth and growth indices of Nigella sativa crop and to determine the association between yield and growth characteristics at both the single plant and crop stand level. The 2-year experiment was laid out in a split-plot design, with three replications, two main plots (200 and 300 plants m-2) and four sub-plots (fertilization treatments: control, compost, farmyard manure and inorganic fertilizer). The highest absolute growth rate (AGR) (0.0321 g day-1) and relative growth rate (RGR) (0.0714 g g-1 day-1) values were recorded when plants subjected to low-density and inorganic fertilization, while the highest crop growth rate (CGR) (8.0342 g m-2 day-1) was obtained under high-plant density and inorganic fertilization. Concerning specific leaf area (SLA), the highest value (196.28 cm2 g-1) was found in inorganic fertilized treatment. Leaf area index (LAI), Leaf area duration (LAD) and Biomass duration (BMD) were positively affected by both plant density and fertilization with the greatest values observed under high-density and fertilization. In conclusion, plant densities higher than 200 plants m-2 lead to higher crop growth, but lower growth of individual plants and decreased seed yield, while the application of inorganic fertilizers increases crop growth and yield as these fertilizers contain higher levels of nitrogen with high solubility and therefore quick availability for the crop than the organic fertilizers.

scholarly journals Effects of DCD addition to slurry on nitrate leaching in sandy soils

1995 ◽  
Vol 43 (2) ◽  
pp. 195-204 ◽  
Author(s):  
W.J. Corre ◽  
K.B. Zwart
Keyword(s):  
Vertical Distribution ◽  
Nitrate Leaching ◽  
Soil Layer ◽  
Nitrification Inhibitor ◽  
Sandy Soils ◽  
Mineral Nitrogen ◽  
Cattle Slurry ◽  
Time Of Application ◽  
One Year ◽  
The Vertical Distribution

The effects of the addition of the nitrification inhibitor dicyandiamide (DCD) to cattle slurry, applied in autumn to an arable sandy soil, were investigated in a three-year field experiment in the Netherlands. Treatments included application of slurry with DCD in November and December, application of slurry without DCD in November, December and January, and an untreated (slurry or DCD) control. Degradation of DCD, changes in mineral nitrogen in the soil, and leaching of nitrate and DCD were measured. Degradation of DCD in the topsoil was complete in May after application in the autumn before. However, at a depth of 90 cm, DCD was found three months after application. DCD remained present in leachate sampled at this depth for more than one year after application. Most probably it was then leached to the groundwater. Application of DCD considerably delayed nitrification. It had a large effect on the vertical distribution of mineral nitrogen in spring; more mineral nitrogen was found in the 0-40 cm soil layer and less in the 40-100 cm soil layer. However, neither time of application of the slurry nor addition of DCD had a significant effect on nitrate leaching.

scholarly journals Effect of Planting Density on the Yield and Growth of Intercropped Tomatoes and Peppers in Florida

HortScience ◽  
2021 ◽  
Vol 56 (2) ◽  
pp. 286-290
Author(s):  
Ravneet K. Sandhu ◽  
Nathan S. Boyd ◽  
Lincoln Zotarelli ◽  
Shinsuke Agehara ◽  
Natalia Peres
Keyword(s):  
Plant Density ◽  
Gulf Coast ◽  
Bell Pepper ◽  
Production Costs ◽  
Planting Density ◽  
Shoot Biomass ◽  
High Plant Density ◽  
Plant Densities ◽  
High Production ◽  
Research And Education

Florida vegetable growers are facing high production costs due to high input costs, lower profitability, and competition from foreign markets. Multi/intercropping allows growers to increase the yields and profits per unit area by producing multiple crops on the same beds. Experiments determining the effects of intercropping and plant spacing was conducted in Fall 2018 and 2019 at Gulf Coast Research and Education Center, Balm. Tomato and bell pepper were intercropped at low and high planting density on plastic-covered beds. Bell pepper shoot biomass was significantly (P < 0.001) reduced when intercropped with tomato, compared with monocropped bell pepper. However, tomato shoot biomass was significantly reduced when tomato plant density increased, but it was unaffected by bell pepper intercropping. Biomass of both crops was unaffected by relay cropping. Bell pepper yields when intercropped with tomato at low density (60 cm tomato-tomato and 38 cm pepper-pepper) had similar yields to bell pepper planted alone in low and high planting density. We concluded that bell pepper plants were more sensitive to interspecific competition, whereas tomato plants were more sensitive to intraspecific competition. Intercropping may be a viable option for growers at recommended plant densities used for monocrops. However, high plant density is not recommended.

scholarly journals Tillering does not interfere on white oat grain yield response to plant density

2003 ◽  
Vol 60 (2) ◽  
pp. 253-258 ◽  
Author(s):  
Milton Luiz de Almeida ◽  
Luís Sangoi ◽  
Márcio Ender ◽  
Anderson Fernando Wamser
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Plant Density ◽  
Dry Mass ◽  
Main Stem ◽  
Yield Response ◽  
Individual Plant ◽  
Growing Seasons ◽  
Plant Densities

Plant density is one of the cropping practices that has the largest impact on individual plant growth. This work was conducted to evaluate the response of white oat (Avena sativa) cultivars with contrasting tillering patterns to variations in plant density. Two field experiments were carried out in Lages, SC, Brazil, during the 1998 and 1999 growing seasons. A split plot experimental design was used. Four oat cultivars were tested in the main plots: UFRGS 14, UFRGS 18, UPF 16 and UPF 17 using five plant densities split plots: 50, 185, 320, 455 and 550 plants m-2. Five plant samples were taken 25, 34, 48, 58 and 70 days after plant emergence to assess the treatment effects on dry matter partition between main stem and tillers. UFRGS 18 promoted dry matter allocation to tillers whereas UPF 17 directed dry mass mostly to the main stem. Differences in dry mass allocation between the main stem and tillers had no impact on grain yield, UPF 16 presenting the highest values for both growing seasons. The lack of interaction between population density and cultivar and the small effect of plant population on grain yield indicates that the oat tillering ability is not fundamental to define its grain yield.

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