scholarly journals Variability of quackgrass (Agripyron repens) biotypes in Québec

2005 ◽  
Vol 72 (3) ◽  
pp. 115-121 ◽  
Author(s):  
F.J. Tardif ◽  
G.D. Leroux
Keyword(s):  
Sexual Reproduction ◽  
Biomass Allocation ◽  
Field Experiments ◽  
Dry Weight ◽  
Total Biomass ◽  
Growth Variability ◽  
Rhizome Buds ◽  
Agropyron Repens

Field experiments were conducted in 1985 and 1986 at Sainte-Foy, Quebec, Canada, to characterize the growth variability of 10 quackgrass (Agropyron repens) biotypes collected in Quebec. The growth variables and the pattern of biomass allocation differed significantly among biotypes. Three-fold difference existed among biotypes for the number of tillers and spikes. The number of daughter-shoots varied from 6 to 51. More than 1900 rhizome buds were formed by the most productive biotypes and fewer than 500 by the least productive ones. Biomass varied from 73 to 241 g dry weight between the least and the most productive biotype. The percentage of total biomass allocated to the mother-shoot and the daughter-shoots varied more between years and among biotypes than the percentage allocated to the rhizomes. Reproduction in quackgrass is predominantly vegetative and sexual reproduction is more variable among biotypes and years.

Use of Infrared Thermometry in Determining Critical Stress Periods Induced by Quackgrass (Agropyron repens) in Soybeans (Glycine max)

Weed Science ◽  
1987 ◽  
Vol 35 (6) ◽  
pp. 784-791 ◽  
Author(s):  
Peter H. Sikkema ◽  
Jack Dekker
Keyword(s):  
Glycine Max ◽  
Field Experiments ◽  
Yield Loss ◽  
Leaf Growth ◽  
Soybean Seed ◽  
Dry Weight ◽  
Critical Periods ◽  
Soybean Yield ◽  
Infrared Thermometry ◽  
Agropyron Repens

Field experiments were conducted during 1981 and 1982 in Ontario, Canada, on the effects of quackgrass [Agropyron repens(L.) Beauv. # AGRRE] interference in soybean [Glycine max(L.) Merr.] and the usefulness of infrared thermometry in predicting critical periods of weed interference. Soybean seed yield, dry weight, number of leaves, height, and number of pods were substantially reduced due to quackgrass interference. High levels of P and K fertility did not overcome the quackgrass interference. Part of the competitive effects of quackgrass was alleviated by irrigation. Infrared thermometry successfully detected the first occurrence of quackgrass-induced stress during the early soybean flowering stage, when the quackgrass was in the four-leaf gtowth stage. This coincided with the onset of the first significant soybean yield loss. No additional soybean yield loss occurred after quackgrass reached the five-leaf growth stage. There was an inverse relation between accumulated stress degree days and soybean yield reductions due to quackgrass interference. The use of the stress degree day concept may be a valuable tool in predicting soybean yield losses due to quackgrass interference.

Growth and Development of Quackgrass (Agropyron repens) Biotypes

Weed Science ◽  
1981 ◽  
Vol 29 (1) ◽  
pp. 44-52 ◽  
Author(s):  
P. H. Westra ◽  
D. L. Wyse
Keyword(s):  
Growth And Development ◽  
Field Experiments ◽  
Reproductive Potential ◽  
Dry Weight ◽  
Leaf Pubescence ◽  
Flag Leaves ◽  
Shoot Dry Weight ◽  
Shoot Production ◽  
Dark Green ◽  
Agropyron Repens

Greenhouse and field experiments (at Rosemount and Roseau, Minnesota) were conducted to characterize the growth and development of 10 quackgrass [Agropyron repens (L.) Beauv.] biotypes selected near Roseau, Minnesota. The biotypes were highly variable for all traits studied. Eight of the biotypes had flag leaves approximately 1 cm wide, but two biotypes had flag leaves approximately 1.5 cm wide. Four biotypes were glaucous and blue-green in color, and the other biotypes varied from light to dark green and had varying leaf pubescence. In the field, plant height varied from 59 to 79 cm, and rhizome length varied from 105 to 135 cm. Spike production varied from 4 to 62 spikes per plant, and mid-season rhizome bud production varied from 246 to 1,211 buds, suggesting that the biotypes varied in their reproductive potential. Shoot dry weight varied from 48 to 362 g per plant, and daughter shoot production varied from 7 to 235 shoots per plant. The quackgrass near Roseau, Minnesota, appears to be made up of several distinct biotypes.

Effect of different nutrient levels on the resistance of soybean to Macrophomina phaseolina infection in field experiments

2008 ◽  
Vol 56 (3) ◽  
pp. 357-362 ◽  
Author(s):  
I. Csöndes ◽  
K. Balikó ◽  
A. Dégenhardt
Keyword(s):  
Biomass Production ◽  
Field Experiments ◽  
Nitrogen Concentration ◽  
Dry Weight ◽  
Macrophomina Phaseolina ◽  
Root Weight ◽  
Total Biomass ◽  
Weight Yield ◽  
Lower Infection ◽  
Fertilizer Rates

Field experiments were carried out with soybean [ Glycine max (L.) Merrill] on a Haplic Chernozem soil. Eleven treatment combinations were applied with increasing rates of fertilizers in three replicates. At full maturity the dry weight production, total biomass production, root weight, yield, shoot NPK concentration and severity of Macrophomina phaseolina infection were determined. The highest degree of Macrophomina infection was found in the lowest NPK treatment, while the lowest rate of disease was observed for the highest NPK combination. By increasing the NK supply, the degree of infection decreased. At the same fertilizer rates, significantly lower infection was observed at higher phosphorus levels. The dry weight production, total biomass production of the shoots, pod weight and nitrogen concentration of the shoots were negatively correlated with the rate and severity of infection, which was positively correlated with the concentration of phosphorus. No correlation was found between root weight and infection or between potassium concentration and infection.

Biennial wormwood (Artemisia biennis) biomass allocation and seed production

Weed Science ◽  
2004 ◽  
Vol 52 (2) ◽  
pp. 246-254 ◽  
Author(s):  
Kris J. Mahoney ◽  
George O. Kegode
Keyword(s):  
Seed Production ◽  
Great Plains ◽  
Biomass Allocation ◽  
Field Experiments ◽  
Dry Weight ◽  
Day Length ◽  
Northern Great Plains ◽  
Allocation Patterns ◽  
Total Dry Weight ◽  
Photoperiod Sensitive

Biennial wormwood has become an important weed problem in the northern Great Plains, but little is known about its biology. Biennial wormwood seeds were collected from Fargo, ND, and Fergus Falls, MN, for field experiments in 1999 and 2000 to determine the influence of transplanting date on growth, biomass, and seed production. Seeds were seeded in a greenhouse every 2 wk, and seedling rosettes were transplanted to the field 2 wk after emergence from April 30 until September 15 to simulate season-long emergence. Weekly destructive subsampling started 2 wk after transplanting and ended on September 29 in both years. All seedlings that grew for at least 5 wk after transplanting produced flowers by mid- to late August of the same year. Late-transplanted seedlings with less than 5 wk of growth did not flower or survive the winter. Biennial wormwood biomass allocation patterns resemble those of an annual species, with about 15% of the total dry weight allocated to roots, 20% to stems, 25% to leaves, and 40% to flowers. Transplant date had a substantial influence on biomass partitioning. Seedlings transplanted early in the growing season produced more biomass and seed than late-season transplants. Biennial wormwood seedlings transplanted on April 30 produced over 435,000 seeds per plant, whereas seedlings transplanted on August 15 produced 500 to 3,000 seeds. Biennial wormwood was photoperiod sensitive and flowered when the day length was about 14 h or less, between August 18 and 25, in both years.

Contrasting yield formation characteristics in two super-rice hybrids that differ in growth duration

2021 ◽  
pp. 1-10
Author(s):  
Min Huang ◽  
Zui Tao ◽  
Tao Lei ◽  
Fangbo Cao ◽  
Jiana Chen ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Biomass Production ◽  
Field Experiments ◽  
Crop Improvement ◽  
Total Biomass ◽  
Growth Duration ◽  
Area Index ◽  
Rice Hybrid ◽  
Use Efficiency ◽  
Yield Formation

Summary The development of high-yielding, short-duration super-rice hybrids is important for ensuring food security in China where multiple cropping is widely practiced and large-scale farming has gradually emerged. In this study, field experiments were conducted over 3 years to identify the yield formation characteristics in the shorter-duration (∼120 days) super-rice hybrid ‘Guiliangyou 2’ (G2) by comparing it with the longer-duration (∼130 days) super-rice hybrid ‘Y-liangyou 1’ (Y1). The results showed that G2 had a shorter pre-heading growth duration and consequently a shorter total growth duration compared to Y1. Compared to Y1, G2 had lower total biomass production that resulted from lower daily solar radiation, apparent radiation use efficiency (RUE), crop growth rate (CGR), and biomass production during the pre-heading period, but the grain yield was not significantly lower than that of Y1 because it was compensated for by the higher harvest index that resulted from slower leaf senescence (i.e., slower decline in leaf area index during the post-heading period) and higher RUE, CGR, and biomass production during the post-heading period. Our findings suggest that it is feasible to reduce the dependence of yield formation on growth duration to a certain extent in rice by increasing the use efficiency of solar radiation through crop improvement and also highlight the need for a greater fundamental understanding of the physiological processes involved in the higher use efficiency of solar radiation in super-rice hybrids.

Biomass allocation in tomato (Lycopersicon esculentum) plants grown under partial rootzone drying: enhancement of root growth

2004 ◽  
Vol 31 (10) ◽  
pp. 971 ◽  
Author(s):  
Darren M. Mingo ◽  
Julian C. Theobald ◽  
Mark A. Bacon ◽  
William J. Davies ◽  
Ian C. Dodd
Keyword(s):  
Lycopersicon Esculentum ◽  
Root System ◽  
Biomass Allocation ◽  
Root Biomass ◽  
Leaf Water ◽  
Total Biomass ◽  
Split Root ◽  
Split Root System ◽  
Partial Rootzone Drying ◽  
And Control

Tomato (Lycopersicon esculentum Mill.) plants were grown in either a glasshouse (GH) or a controlled environment cabinet (CEC) to assess the effects of partial rootzone drying (PRD) on biomass allocation. Control and PRD plants received the same amounts of water. In control plants, water was equally distributed between two compartments of a split-root system. In PRD plants, only one compartment was watered while the other was allowed to dry. At the end of each drying cycle, wet and dry compartments were alternated. In the GH, total biomass did not differ between PRD and control plants after four cycles of PRD, but PRD increased root biomass by 55% as resources were partitioned away from shoot organs. In the CEC, leaf water potential did not differ between treatments at the end of either of two cycles of PRD, but stomatal conductance of PRD plants was 20% less at the end of the first cycle than at the beginning. After two cycles of PRD in the CEC, biomass did not differ between PRD and control plants, but PRD increased root biomass by 19% over the control plants. The promotion of root biomass in PRD plants was associated with the alternation of wet and dry compartments, with increased root biomass occurring in the re-watered compartment after previous exposure to soil drying. Promotion of root biomass in field-grown PRD plants may allow the root system to access resources (water and nutrients) that would otherwise be unavailable to control plants. This may contribute to the ability of PRD plants to maintain similar leaf water potentials to conventionally irrigated plants, even when smaller irrigation volumes are supplied.

scholarly journals Sulfur application alleviates chromium stress in maize and wheat

2020 ◽  
Vol 18 (1) ◽  
pp. 1093-1104
Author(s):  
Grzegorz Kulczycki ◽  
Elżbieta Sacała
Keyword(s):  
Adverse Effects ◽  
Mineral Nutrition ◽  
Elemental Sulfur ◽  
Marked Decrease ◽  
Total Yield ◽  
Growth Yield ◽  
Dry Weight ◽  
Total Biomass ◽  
Cr Content ◽  
Chromium Stress

AbstractThis study aimed to examine the influence of increasing doses of chromium (Cr) (26, 39, and 52 mg kg−1 soil) and elemental sulfur (S) (60 mg kg−1 soil) on growth, yield, and mineral nutrition in wheat and maize. Macro- and micronutrients and Cr concentrations were determined in the aboveground parts of plants. All examined doses of Cr caused a marked decrease in the fresh and dry weight of maize. Wheat was more tolerant than maize, and lower Cr doses caused a small but statistically significant increase in the total yield. Wheat accumulated more than twofold Cr than maize, and the concentrations increased with higher Cr concentrations in the soil. The application of S significantly improved the total biomass production and lowered the Cr content in both plants. Cr changed the mineral nutrition in both cereals, but the pattern of changes observed was not the same. Applying S alleviated some adverse effects caused by the Cr. Hence, it is concluded that the application of elemental S may be an effective strategy to reduce adverse effects in plants grown on soil contaminated by heavy metals, especially Cr.

Diet of European freshwater pearl mussels Margaritifera margaritifera (Mollusca: Bivalvia: Unionoida) in small river (Republic of Karelia, Russia)

2021 ◽  
Vol 325 (4) ◽  
pp. 502-515
Author(s):  
S.F. Komulaynen
Keyword(s):  
Algal Species ◽  
Dry Weight ◽  
Lake Ladoga ◽  
Total Biomass ◽  
Margaritifera Margaritifera ◽  
Pearl Mussel ◽  
Organic Detritus ◽  
Unicellular Algae ◽  
Wide Range ◽  
Intestinal Contents

The freshwater pearl mussel Margaritifera margaritifera (Linnaeus,1758) is endangered in Europe and is now listed in the Red Data Book of many countries and regions. The diet of the species in the Syskyänjoki River (a tributary of Lake Ladoga) has been studied. The contents of the intestine generally correspond to the composition of seston, and include organic detritus, filamentous and unicellular algae, fragments of invertebrates and macrophyte tissues mixed with silt and sand. The total biomass of the intestinal contents of varied from 0.8 to 30.6 mg per organism (absolutely dry weight). Margaritifera margaritifera consumes a wide range of particles, from 0.5 μm3 (bacteria and unicellular algae) to 200 000 μm3 (fragments of invertebrates and macrophyte tissues). About 90–95% (by volume) of the intestinal contents was consisted by fine organic detritus. The food composition did not differ significantly for mollusks of different sexes and size. In the intestinal contents, 63 taxa of algae were identified. The number of algal species in the content of one intestine varied from 3 to 17, with their abundance from 250 to 9560 cells per organism. The most abundant and constant in the contents of the intestines are unicellular algae. Diatoms are the most diverse, they make up 50.8% of the total number of species.

scholarly journals Effects of Cover Methods and Nitrogen Levels on the Growth and Yield of Tomato

2021 ◽  
Vol 4 (2) ◽  
pp. 1021-1033
Author(s):  
Nguyen Thi Loan ◽  
Tran Thi My Can
Keyword(s):  
Yield Components ◽  
Field Experiments ◽  
Block Design ◽  
Tomato Fruit ◽  
Dry Weight ◽  
Fruit Yield ◽  
Growth And Yield ◽  
Plastic Mulch ◽  
Yield Attributes ◽  
Black Plastic

To study the effects of cover methods and nitrogen (N) levels on the growth and yield components of tomato Cv. Pear F1, field experiments with a 4x3 factorial design were conducted in the 2019 spring and winter seasons using a randomized complete block design with three replications. The cover methods included four treatments: bare soil (BS), black plastic mulch (BPM), transparent polypropylene row cover (RC), and a combination of BPM and RC (BPMRC) with the RC removed approximately 30 days after transplanting. Nitrogen (N) was applied at three levels (150, 180, and 210 kg N ha-1). Using BPM and RC generally led to an increased air temperature, air humidity, soil moisture, and soil temperature compared to the BS treatment. Higher N rates (180 and 210 kg N ha-1) did not result  in different tomato fruit sizes and fruit weights but positively increased fruit yield and quality (Brix values and fruit dry weight) as compared to the 150 kg N ha-1 addition. The cover methods positively affected the yield components and fruit yield of tomato as well as the fruit characteristics compared to the BS treatment. Using cover materials (BPM and RC) combined with a higher N application significantly increased the yield attributes and fruit yield. The highest fruit yield was achieved under the mulching treatment by black plastic (BPM treatment) combined with a 210 kg N ha-1 application, resulting in 50.90 tons ha-1 in the spring and 58.27 tons ha-1 in the winter.

scholarly journals Análisis de crecimiento de tres especies de Caesalpinia (Leguminosae) de la selva baja caducifolia de Chamela, Jalisco

2017 ◽  
pp. 5
Author(s):  
Emmanuel Rincón ◽  
Pilar Huante ◽  
Mariana Álvarez-Añorve
Keyword(s):  
Leaf Area ◽  
Biomass Allocation ◽  
Deciduous Forest ◽  
Growth Period ◽  
Growth Patterns ◽  
Tropical Deciduous Forest ◽  
Total Biomass ◽  
Allocation Pattern ◽  
Location Patterns ◽  
Net Assimilation

The objective of this study is to assess the biomass allocation pattern s and growth characteristics of three species of Caesalpinia (Leguminosae) from the highly diverse and seasonal Chamela tropical deciduous forest , where the plant growth period is restricted to the rainy season. The studied species, although they are phylogenetically related, presented different biomass al location patterns and RGR during growth, in order to carry out a differential exploitation of resources and to promote their coexistence. There were differences in relative growth rate (RGR), root to shoot ratio (R/ S), net assimilation rate (E), biomass allocation patterns and total biomass and leaf area attained among the studied species. Caesalpinia eriostachys and C. platyloba showed similar growth patterns between them but contrasting with those of C. sclerocarpa. This suggests a temporal uncuopling of their maximum resource demand. RGR was determined to a greater extent by parameters related with E than by parameters related with the specific leaf area (SLA).

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