Effects of shading on common waterhemp (Amaranthus rudis) growth and development

Weed Science ◽  
2003 ◽  
Vol 51 (6) ◽  
pp. 898-903 ◽  
Author(s):  
Lawrence E. Steckel ◽  
Christy L. Sprague ◽  
Aaron G. Hager ◽  
F. William Simmons ◽  
German A. Bollero
Keyword(s):  
Growth And Development ◽  
Plant Biomass ◽  
Cropping Systems ◽  
Growing Season ◽  
Viable Seed ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Common Waterhemp ◽  
Amaranthus Rudis ◽  
Vegetative And Reproductive Growth

Common waterhemp is a significant weed problem in Midwestern cropping systems partly because of its potential for multiple emergence events during the growing season. The effects of shade and time of emergence on this weed have not been characterized. In the field, common waterhemp vegetative and reproductive growth were evaluated under different irradiance levels at two emergence times. In full sunlight a common waterhemp plant emerging in late May produced 720 g of biomass and over one million seeds, and a plant emerging in late June produced 350 g of biomass and over 730,000 seeds. Plant biomass and seed production were lower as irradiance levels were decreased to 40, 68, and 99% shade. Mortality was high for common waterhemp grown in 99% shade; however, surviving plants produced some viable seed. Common waterhemp plants grown under reduced irradiance had higher leaf area ratios and lower relative growth rates.

Growth and Development of Organic Arsenical-Susceptible and -Resistant Common Cocklebur (Xanthium strumarium) Biotypes Under Noncompetitive Conditions

1994 ◽  
Vol 8 (1) ◽  
pp. 154-158 ◽  
Author(s):  
William E. Haigler ◽  
Billy J. Gossett ◽  
James R. Harris ◽  
Joe E. Toler
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Plant Height ◽  
Growth And Development ◽  
Reproductive Potential ◽  
Dry Weight ◽  
Growing Season ◽  
Xanthium Strumarium ◽  
Relative Growth ◽  
Growth Development

The growth, development, and reproductive potential of several populations of organic arsenical-susceptible (S) and -resistant (R) common cocklebur biotypes were compared under noncompetitive field conditions. Plant height, leaf area, aboveground dry weights, and relative growth rate (RGR) were measured periodically during the growing season. Days to flowering, bur dry weight, and number of burs per plant were also recorded. Arsenical S- and R-biotypes were similar in all measured parameters of growth, development, and reproductive potential. Populations within each biotype varied occasionally in plant height, leaf area, aboveground dry weights, and reproductive potential.

scholarly journals Affordable Phenotyping of Winter Wheat under Field and Controlled Conditions for Drought Tolerance

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 882
Author(s):  
Dhananjay Kumar ◽  
Sandeep Kushwaha ◽  
Chiara Delvento ◽  
Žilvinas Liatukas ◽  
Vivekanand Vivekanand ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Winter Wheat ◽  
Growth Rates ◽  
Plant Biomass ◽  
Growth Conditions ◽  
Seedling Stage ◽  
Growth Stages ◽  
Digital Cameras ◽  
Relative Growth ◽  
Relative Growth Rates

Drought stress is one of the key plant stresses reducing grain yield in cereal crops worldwide. Although it is not a breeding target in Northern Europe, the changing climate and the drought of 2018 have increased its significance in the region. A key challenge, therefore, is to identify novel germplasm with higher drought tolerance, a task that will require continuous characterization of a large number of genotypes. The aim of this work was to assess if phenotyping systems with low-cost consumer-grade digital cameras can be used to characterize germplasm for drought tolerance. To achieve this goal, we built a proximal phenotyping cart mounted with digital cameras and evaluated it by characterizing 142 winter wheat genotypes for drought tolerance under field conditions. The same genotypes were additionally characterized for seedling stage traits by imaging under controlled growth conditions. The analysis revealed that under field conditions, plant biomass, relative growth rates, and Normalized Difference Vegetation Index (NDVI) from different growth stages estimated by imaging were significantly correlated to drought tolerance. Under controlled growth conditions, root count at the seedling stage evaluated by imaging was significantly correlated to adult plant drought tolerance observed in the field. Random forest models were trained by integrating measurements from field and controlled conditions and revealed that plant biomass and relative growth rates at key plant growth stages are important predictors of drought tolerance. Thus, based on the results, it can be concluded that the consumer-grade cameras can be key components of affordable automated phenotyping systems to accelerate pre-breeding for drought tolerance.

scholarly journals Performance of Two Bioherbicide Fungi for Waterhemp and Pigweed Control in Pumpkin and Soybean

Plant Disease ◽  
2011 ◽  
Vol 95 (4) ◽  
pp. 469-477 ◽  
Author(s):  
Loretta M. Ortiz-Ribbing ◽  
Kenny R. Glassman ◽  
Gordon K. Roskamp ◽  
Steven G. Hallett
Keyword(s):  
Cropping Systems ◽  
Disease Incidence ◽  
Field Trials ◽  
Weed Biomass ◽  
Common Waterhemp ◽  
Air Temperatures ◽  
Amaranthus Rudis ◽  
Fungal Organisms ◽  
Sequential Treatments ◽  
Amaranthus Spp

Common waterhemp (Amaranthus rudis) and pigweeds (Amaranthus spp.) are troublesome weeds in many cropping systems and have evolved resistance to several herbicides. Field trials to further develop Microsphaeropsis amaranthi and Phomopsis amaranthicola as bioherbicides for control of waterhemp and pigweeds were conducted to test the effectiveness of these organisms in irrigated and nonirrigated pumpkin and soybean plots over 2 years at three locations in western Illinois. The bioherbicide was applied with lecithin and vegetable oil at 187 liters ha–1 in 2008 and 374 liters ha–1 in 2009. Treatments included spore suspensions of M. amaranthi and P. amaranthicola alone, a mixture of both organisms, and sequential treatments of the organisms with halosulfuron-methyl (Sandea Herbicide) in pumpkin or glyphosate (Roundup Original Max Herbicide) in soybean. Bioherbicide effectiveness was estimated at approximately 7 and 14 days after treatment, as disease incidence, disease severity, percent weed control, and weed biomass reduction. Significant reductions in weed biomass occurred in treatments with one or both of the fungal organisms, and potential exists to tank mix M. amaranthi with halosulfuron-methyl. Leaf surface moisture and air temperatures following application may account for inconsistencies in field results between year and locations. These fungal organisms show potential as bioherbicides for weeds in the genus Amaranthus.

Growth and Development of Dinitroaniline-Susceptible and -Resistant Goosegrass (Eleusine indica) Biotypes Under Noncompetitive Conditions

Weed Science ◽  
1986 ◽  
Vol 34 (5) ◽  
pp. 704-710 ◽  
Author(s):  
Tim R. Murphy ◽  
Billy J. Gossett ◽  
Joe E. Toler
Keyword(s):  
Growth And Development ◽  
Growth Parameters ◽  
Flag Leaf ◽  
Dry Weight ◽  
Growing Season ◽  
Leaf Length ◽  
Relative Growth ◽  
Eleusine Indica ◽  
Flag Leaf Length ◽  
Weight Number

A comparative study of the growth and development of several populations of dinitroaniline-susceptible (DS) and -resistant (DR) goosegrass [Eleusine indica(L.) Gaertn. # ELEIN] biotypes was conducted under noncompetitive field conditions. Plant height and width, number of tillers, aboveground dry weight, relative growth rate (RGR), number of inflorescences/plant, total inflorescence dry weight, individual inflorescence dry weight, number of spicate branches/inflorescence, and flag leaf length and width were recorded periodically during the growing season. There were no significant differences between biotypes in most characteristics with the exception of total inflorescence dry weight. The DS biotype produced more total inflorescence dry weight than the DR biotype at 8 and 13 weeks after transplanting. Significant variation among DS and DR populations occurred in 37 and 33 of 56 evaluations, respectively. When variation existed within a biotype, populations exhibited broad ranges of response for the various growth parameters. With the exception of total inflorescence dry weight, DS and DR biotypes generally exhibited similar ranges of variability.

Growth and development of pigs: a reanalysis of the effects of nutrition on body composition

1983 ◽  
Vol 100 (3) ◽  
pp. 681-687 ◽  
Author(s):  
A. S. Davies
Keyword(s):  
Body Composition ◽  
Head And Neck ◽  
Growth Rates ◽  
Growth And Development ◽  
Fat Content ◽  
The Body ◽  
Total Weight ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Poor Nutrition

SUMMARYSelected data of McMeekan (1940, 1941) were reanalysed to compare the proportions and distribution of tissues, and the weights of some organs, in pigs growing at different growth rates due to differing levels of nutrition. The effects of variation in fat content were excluded, and the distribution of tissues was compared at the same total weight for each tissue, by allometric regressions. Except for components of the head and neck, and the stomach, the results do not support a concept of retardation of development by poor nutrition of those parts of the body with the highest relative growth rates.

Carbon and nitrogen allocation patterns of Douglas-fir seedlings fertilized with nitrogen in autumn. II. Field performance

1986 ◽  
Vol 16 (5) ◽  
pp. 903-909 ◽  
Author(s):  
H. A. Margolis ◽  
R. H. Waring
Keyword(s):  
Free Amino ◽  
Shoot Growth ◽  
Field Performance ◽  
Growing Season ◽  
Frost Damage ◽  
Douglas Fir ◽  
Summer Drought ◽  
Tree Roots ◽  
Relative Growth ◽  
Relative Growth Rates

October-fertilized and unfertilized 2-0 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings were outplanted the following February. Half of each planting block was seeded with grass to induce water stress during the typical summer drought. Sucrose was applied to soil around each seedling to limit availability of nitrogen to tree roots. Fertilized seedlings broke bud 9–10 days earlier, produced more shoot growth, and, as shown in later harvests, had higher relative growth rates than unfertilized seedlings. However, initial differences in growth response were due primarily to the earlier budbreak. Seedlings growing with grass had predawn water potentials of −1.5 MPa by early August; by September 3, unfertilized seedlings growing with grass were significantly more stressed than any others. Although free amino acid and total nitrogen concentrations were higher in fertilized than unfertilized seedlings when planted, they became equal by the end of one growing season. However, fertilized seedlings contained more free amino acids and nitrogen because of their greater size. Grass competition affected both seedling nitrogen and carbohydrate chemistry. After one growing season, fertilized seedlings had greater height increment, shoot growth, leaf area, relative growth rate, and production per unit nitrogen. Although autumn fertilization benefited these Douglas-fir seedlings, negative effects could result from carbohydrate depletion because of increased respiration or from frost damage because of earlier budbreak.

Relative Competitiveness of Protoporphyrinogen Oxidase-Resistant Common Waterhemp (Amaranthus Rudis)

Weed Science ◽  
2009 ◽  
Vol 57 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Michael G. Duff ◽  
Kassim Al-Khatib ◽  
Dallas E. Peterson
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Selection Pressure ◽  
Plant Biomass ◽  
Single Plant ◽  
Replacement Series ◽  
Protoporphyrinogen Oxidase ◽  
Common Waterhemp ◽  
Amaranthus Rudis ◽  
Series Study

Research was conducted to determine the competitiveness and fitness of a protoporphyrinogen oxidase (protox)-resistant common waterhemp biotype. Protox-resistant and protox-susceptible biotypes were grown under noncompetitive and competitive arrangements in the greenhouse. In the noncompetitive study, a single plant of each biotype was planted separately in 15-cm-diam pots. Photosynthesis, leaf area, and plant biomass were measured 10, 20, 30, and 40 d after transplanting (DATP). In general, photosynthesis rate and plant biomass were similar between biotypes. However, the protox-resistant biotype had higher leaf area than the susceptible biotype at 20, 30, and 40 DATP. A replacement series study was conducted in the greenhouse to evaluate the relative competitiveness of protox-resistant and protox-susceptible common waterhemp. Photosynthesis, leaf area, plant height, and plant biomass were measured 7, 14, 21, and 28 DATP. Protox-resistant and -susceptible common waterhemp were equally competitive 28 DATP. Relative crowding coefficient values 28 DATP were 0.86, 0.89, 1.09, and 1.13 for photosynthesis, leaf area, plant height, and plant biomass, respectively. This suggests protox-resistant and -susceptible common waterhemp were equally competitive and the frequency of protox-resistant biotype is unlikely to decrease in the absence of protox–herbicide selection pressure.

scholarly journals THE GROWTH AND ABSORPTION OF NUTRIENTS BY FERTILIZED AND UNFERTILIZED WHITE SPRUCE SEEDLINGS

1966 ◽  
Vol 42 (2) ◽  
pp. 127-136 ◽  
Author(s):  
K. A. Armson
Keyword(s):  
Growth Rate ◽  
Growth And Development ◽  
Dry Weight ◽  
Growing Season ◽  
White Spruce ◽  
Height Growth ◽  
Relative Growth ◽  
Uptake Rates ◽  
Abrupt Changes ◽  
Growth Development

A study was made of the effects of fertilizer additions on the growth and development of white spruce seedlings during their second growing season. In terms of dry weight increment, unfertilized trees grew for only two-thirds of the total growing season available as compared with fertilized trees. The relative growth rate curve for the fertilized trees was smooth with none of the abrupt changes which marked the curve for the unfertilized trees. The pattern of height growth was changed for seedlings which were fertilized. Nutrient uptake rates particularly for phosphorus were different under the two treatments and it is suggested that these differences were related to different patterns of height growth development and root extension.

Growth and development of the Murid Pseudomys novaehollandiae

1976 ◽  
Vol 24 (1) ◽  
pp. 27 ◽  
Author(s):  
CM Kemper
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growth And Development ◽  
Adult Size ◽  
Body Measurements ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Straight Line ◽  
Length Measurements ◽  
Hind Foot

Growth of the hind foot, head and weight were studied from birth to 150 days of age in a captive colony of P. novaaehollandiae, and development of external body features was recorded from birth to weaning. The altricial young were sparsely haired and blind at birth and a juvenile pelage was present by about 10 days. The eyes opened at 15 (13-19) days and the young were weaned during the fourth week. Instantaneous relative growth rates showed that growth (weight) during the first 40 days was multiphasic and that the growth rate changed considerably at both the opening of the eyes and weaning. The relationships of seven body measurements (head and body, head, ear, foreleg, hind leg, hind foot and tail) were compared to a linear equivalence of weight; all showed a sigmoidal relationship except that of head and body, which was a straight line. Hind foot and head length measurements of growing animals reached 90% of adult size at about 26 days, and weight at about 85 days. In Australian murids, one group grows relatively quickly and another grows slowly.

scholarly journals Comparison of Herbicide Programs for Season-Long Control of Glyphosate-Resistant Common Waterhemp (Amaranthus rudis) in Soybean

2017 ◽  
Vol 31 (1) ◽  
pp. 53-66 ◽  
Author(s):  
Debalin Sarangi ◽  
Lowell D. Sandell ◽  
Greg R. Kruger ◽  
Stevan Z. Knezevic ◽  
Suat Irmak ◽  
...  
Keyword(s):  
Field Experiments ◽  
Acetolactate Synthase ◽  
Growing Season ◽  
Soybean Field ◽  
Common Waterhemp ◽  
Need To Evaluate ◽  
Amaranthus Rudis ◽  
Reduced Density ◽  
Als Inhibitor ◽  
Herbicide Programs

The evolution of glyphosate and acetolactate synthase (ALS) inhibitor-resistant common waterhemp in the Midwestern United States has reduced the number of effective POST herbicide options for management of this problem weed in glyphosate-resistant soybean. Moreover, common waterhemp emerges throughout the crop growing season, justifying the need to evaluate herbicide programs that provide season-long control. The objectives of this study were to compare POST-only and PRE followed by (fb) POST herbicide programs for control of glyphosate-resistant common waterhemp in glyphosate-resistant soybean. Field experiments were conducted in 2013 and 2014 in Dodge County, NE, in a field infested with glyphosate-resistant common waterhemp. Programs containing PRE herbicides resulted in ≥83% control of common waterhemp and densities of ≤35 plantsm–2at 21 d after PRE (DAPRE). Post-only herbicide programs resulted in <70% control and densities of 107 to 215 plants m–2at 14 d after early-POST (DAEPOST) treatment. PRE fb POST herbicide programs, including saflufenacil plus imazethapyr plus dimethenamid-P, sulfentrazone plus cloransulam, orS-metolachlor plus metribuzin, fb fomesafen plus glyphosate;S-metolachlor plus fomesafen fb acifluorfen plus glyphosate resulted in >90% control of glyphosate-resistant common waterhemp throughout the growing season, reduced density to ≤7plantsm–2, ≥92% biomass reduction, and soybean yield >2,200kg ha–1. Averaged across herbicide programs, common waterhemp control was 84%, and density was 15 plants m–2with PRE fb POST herbicide programs compared with 42% control, and density of 101 plants m–2with POST-only herbicide programs at harvest. Results of this study indicated that PRE fb POST herbicide programs with effective modes of action exist for season-long control of glyphosate-resistant common waterhemp in glyphosate-resistant soybean.

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