scholarly journals Growth behavior and glyphosate resistance level in 10 biotypes of Echinochloa colona in Australia

2019 ◽  
Author(s):  
Gulshan Mahajan ◽  
Vishavdeep Kaur ◽  
Michael Thompson ◽  
Bhagirath S. Chauhan
Keyword(s):  
Plant Height ◽  
Seed Production ◽  
Resistance Index ◽  
Growth Behavior ◽  
Resistance Pattern ◽  
Shoot Biomass ◽  
Seed Number ◽  
Resistance Level ◽  
Seed Head ◽  
Wide Range

AbstractRecently, poor control of Echinochloa colona with glyphosate has been reported in no-till agriculture systems of the northern grain region (NGR) of Australia. Two experiments were conducted using 10 biotypes of E. colona selected from the NGR of Australia to understand differences in their growth behavior and resistance pattern. Growth studies revealed that these biotypes differed in plant height (53-70 cm plant−1), tiller production (30-52 tillers plant−1), leaf production (124-186 leaves plant−1) and seed head production (37-65 seed heads plant−1). Days taken to seed heads and shoot biomass in these biotypes ranged between 40-48 d and 21-27 g plant−1, respectively. Seed production in these biotypes ranged between 5380 and 10244 seeds plant−1; lowest for biotype B17/25 and highest for biotype B17/13. Correlation studies revealed that seed number plant−1 had a positive correlation with plant height (r = 0.67), tiller number plant−1 (r = 0.89), leaf number plant−1 (r = 0.73), seed heads plant−1 (r = 0.78), seed head weight (r = 0.79), shoot biomass (r = 0.77) and root biomass (r = 0.46). The glyphosate dose-response study showed a wide range of responses in these biotypes and the glyphosate dose required to reduce 50% biomass (GR50 values) was estimated between 217 to 2159 g a.e. glyphosate ha−1. GR50 values of biotypes B17/16, B 17/34 and B17/35 were 719, 2159 and 884 g ha−1, respectively, making them 3, 10 and 4-fold resistant to glyphosate compared with the susceptible biotype B17/37. Growth behavior and seed production potential in these biotypes had no correlation with the resistance index. These results suggest that some biotypes of E. colona are highly problematic; for example, biotype B17/34 was not only highly glyphosate-resistant, but also produced a high seed number (9300 seeds plant−1). This study demonstrated that there is a possibility of great risk with the increased use of glyphosate for managing E. colona in the NGR of Australia. The results warrant integrated weed management strategies and improved stewardship guidelines are required for managing glyphosate-resistant biotypes of E. colona and to restrict further movement of resistant biotypes to other regions of Australia.

scholarly journals Evaluation of Herbicide-Resistance Status on Populations of Littleseed Canarygrass (Phalaris Minor Retz.) from Southern Greece and Suggestions for their Effective Control

2012 ◽  
Vol 52 (3) ◽  
pp. 308-313 ◽  
Author(s):  
Ilias Travlos
Keyword(s):  
Herbicide Resistance ◽  
Resistance Index ◽  
Acetolactate Synthase ◽  
Effective Control ◽  
Cross Resistance ◽  
Resistance Mutations ◽  
Resistance Level ◽  
Phalaris Minor ◽  
Wide Range ◽  
Southern Greece

Evaluation of Herbicide-Resistance Status on Populations of Littleseed Canarygrass (Phalaris MinorRetz.) from Southern Greece and Suggestions for their Effective ControlIn 2010, a survey was conducted in the wheat fields of a typical cereal-producing region of Greece to establish the frequency and distribution of herbicide-resistant littleseed canarygrass (Phalaris minorRetz.). In total, 73 canarygrass accessions were collected and screened in a field experiment with several herbicides commonly used to control this weed. Most of the weed populations were classed as resistant (or developing resistance) to the acetyl-CoA varboxylase (ACCase)-inhibiting herbicide diclofop, while resistance to clodinafop was markedly lower. The results of the pot experiments showed that some of the canary populations were found to have a very high level of diclofop resistance (resistance index up to 12.4), while cross resistance with other herbicides was also common. The levels of resistance and cross resistance patterns among populations varied along with the different amounts and times of selection pressure. Such variation indicated either more than one mechanism of resistance or different resistance mutations in these weed populations. The population which had the highest diclofop resistance level, showed resistance to all aryloxyphenoxypropinate (APP) herbicides applied and non-ACCase inhibitors. Alternative ACCase-inhibiting herbicides, such as pinoxaden remain effective on the majority of the tested canarygrass populations, while the acetolactate synthase (ALS)-inhibiting herbicide mesosulfuron + iodosulfuron could also provide some solutions. Consequently, there is an opportunity to effectively control canarygrass by selecting from a wide range of herbicides. It is the integration of agronomic practices with herbicide application, which helps in effective management ofP. minorand particularly its resistant populations.

Growth Response and Carbohydrate Status of Gibberellin-treated Spectral Filter-grown Chrysanthemum Plants

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 522c-522
Author(s):  
Anuradha Tatineni ◽  
Sonja L. Maki ◽  
Nihal C. Rajapakse
Keyword(s):  
Plant Height ◽  
Growth Regulation ◽  
Red Light ◽  
Sucrose Phosphate Synthase ◽  
Spectral Filter ◽  
Spectral Filters ◽  
Wide Range ◽  
Ornamental Crops ◽  
Carbohydrate Levels ◽  
Carbohydrate Status

Interest in the use of non- (or less) chemical methods to reduce the height of ornamental crops has increased tremendously. Manipulation of greenhouse light quality is one alternative for plant growth regulation. We have shown that eliminating far-red light from the greenhouse environment with liquid CuSO4 spectral filters is effective in reducing the height of a wide range of plants though plant carbohydrate status is also altered under CuSO4 filter. In previous studies, application of GA3 reversed both the reduction of plant height and carbohydrate status of CuSO4 spectral filter grown plants. It has been proposed that GAs enhance the activity of the enzyme sucrose phosphate synthase to regulate carbohydrate levels. In the present study the role of exogenously applied GA19, GA1, and GA3 in overcoming the reduction of plant height and carbohydrate levels was investigated. Chrysanthemum plants were treated weekly for 4 weeks with saturating doses of GA19, GA1 and GA3 (25 μg) or the growth retardants paclobutrazol and prohexadione. GA1 was also applied with paclobutrazol and prohexadione to assess whether response to GAs is altered under CuSO4 filter. GA1 and GA3 promoted growth similarly under control or CuSO4 filter. GA19 was least effective in promoting growth under CuSO4 filter. In summary, these results suggest that gibberellin physiology is altered under spectral filters with the conversion of GA19 a possible point of regulation. The correlation between the carbohydrate status and the growth of the plants will be discussed.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

scholarly journals Glyphosate Resistance in Perennial Ryegrass (Lolium perenneL.) is Associated with a Fitness Penalty

Weed Science ◽  
2016 ◽  
Vol 64 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Marcos Yanniccari ◽  
Martín Vila-Aiub ◽  
Carolina Istilart ◽  
Horacio Acciaresi ◽  
Ana M. Castro
Keyword(s):  
Perennial Ryegrass ◽  
Water Availability ◽  
Field Experiments ◽  
Seed Mass ◽  
Selection Effect ◽  
Glyphosate Resistance ◽  
Shoot Biomass ◽  
Seed Number ◽  
Fitness Costs ◽  
Weed Species

The net selection effect of herbicides on herbicide-resistance traits in weeds is conditioned by the fitness benefits and costs associated with resistance alleles. Fitness costs play an important evolutionary role preventing the fixation of adaptive alleles and contributing to the maintenance of genetic polymorphisms within populations. Glyphosate is widely used in world agriculture, which has led to the evolution of widespread glyphosate resistance in many weed species. The fitness of glyphosate-resistant and -susceptible perennial ryegrass plants selected from within a single population were studied in two field experiments conducted during 2011 and 2012 under different soil water availability. Glyphosate-resistant plants showed a reduction in height of 12 and 16%, leaf blade area of 16 and 33%, shoot biomass of 45 and 55%, seed number of 33 and 53%, and total seed mass of 16 and 5% compared to glyphosate-susceptible plants in 2011 and 2012, respectively. The reduction in seed number per plant resulted in a 40% fitness cost associated with the glyphosate-resistance trait in perennial ryegrass. Fitness costs of glyphosate-resistant plants were expressed under both conditions of water availability. These results could be useful for designing management strategies and exploiting the reduced glyphosate-resistant perennial ryegrass fitness in the absence of glyphosate selection.

Contributions of Time Dependent and Cyclic Crack Growth to the Crack Growth Behavior of Non Strain-Crystallizing Elastomers

2002 ◽  
Vol 75 (4) ◽  
pp. 643-656 ◽  
Author(s):  
J. J. C. Busfield ◽  
K. Tsunoda ◽  
C. K. L. Davies ◽  
A. G. Thomas
Keyword(s):  
Crack Growth ◽  
Growth Behavior ◽  
Time Dependent ◽  
Crack Growth Behavior ◽  
Wide Range ◽  
Dependent Component ◽  
Tearing Energy ◽  
Quasi Crystals ◽  
Crack Growth Rates ◽  
Time Dependent Crack Growth

Abstract Engineering components are observed to fail more rapidly under cyclic loading than under static loading. This reflects features of the underlying crack growth behavior. This behavior is characterized by the relation between the tearing energy, T, and the crack growth per cycle, dc/dn. The increment of crack growth during each cycle is shown here to result from the sum of time dependent and cyclic crack growth components. The time dependent component represents the crack growth behavior that would be present in a conventional constant T crack growth test. Under repeated stressing additional crack growth, termed the cyclic crack growth component, occurs. For a non-crystallizing elastomer, significant effects of frequency have been found on the cyclic crack growth behavior, reflecting the presence of this cyclic element of crack growth. The cyclic crack growth behavior over a wide range of frequencies was investigated for unfilled and swollen SBR materials. The time dependent crack growth component was calculated from constant T crack growth tests and the cyclic contribution derived from comparison with the observed cyclic growth. It is shown that decreasing the frequency or increasing the maximum tearing energy during a cycle results in the cyclic crack growth behavior being dominated by time dependent crack growth. Conversely at high frequency and at low tearing energy, cyclic crack growth is dominated by the cyclic crack growth component. A large effect of frequency on cyclic crack growth behavior was observed for highly swollen SBR. The cyclic crack growth behavior was dominated by the time dependent crack growth component over the entire range of tearing energy and/or crack growth rate. The origin of the cyclic component may be the formation/melting of quasi crystals at the crack tip, which is absent at fast crack growth rates in the unswollen SBR and is absent at all rates in the swollen SBR.

The Effect of Pruning and Several Kinds of Growing Media Fertigation Hydroponic Systems Against Protection and Production of Melons (Cucumis Melo L.)

Nabatia ◽  
2016 ◽  
Vol 4 (2) ◽  
pp. 57-63
Author(s):  
M Abror ◽  
M Koko Ardiansyah
Keyword(s):  
Plant Height ◽  
Cucumis Melo ◽  
Fruit Weight ◽  
Growth And Yield ◽  
Leaf Number ◽  
Growing Media ◽  
Hydroponic System ◽  
Wide Range ◽  
Number Of Leaves ◽  
Cucumis Melo L

This study aims to determine the effect of trimming with a wide variety of growing media hydroponic system fertigation on growth and yield of melon. Research will be conducted in the green house (House of plastic) UMSIDA Agriculture Faculty, Campus 2, Gelam, Candi, Sidoarjo, research time between the months of March to June 2016 using analysis of variance and continued test HSD 5%. The variables measured were plant height, leaf number, level of sweetness of fruit, fruit weight, high-fruit, thickness of the flesh of the fruit, conclusion from this research is going on the effect of trimming and a wide variety of growing media hydroponic system fertigation in treatment PM5 (trimming down, kokopit). There was also a real influence on the treatment PM6 (without pruning, kokopit) .In observation of plant height, leaf number, fruit weight, and high fruit. And also happens to influence a wide range of growing media on growth and yield of melon on hydroponics fertigation system, the PM6 treatment (without pruning, kokopit) had the highest rates in the observation of plant height, weight of the fruit, and the number of leaves.

scholarly journals Quantifying seed production by volunteer canola (Brassica napus) and Sinapis arvensis

2011 ◽  
Vol 29 (3) ◽  
pp. 489-497
Author(s):  
E Soltani ◽  
A Soltani ◽  
S Galeshi ◽  
F Ghaderi-far ◽  
E Zeinali
Keyword(s):  
Brassica Napus ◽  
Seed Production ◽  
Cropping Systems ◽  
Plant Size ◽  
Quantitative Information ◽  
Sinapis Arvensis ◽  
Soil Seed Banks ◽  
Sowing Dates ◽  
Wide Range ◽  
Close Relationship

Volunteer canola (Brassica napus) and Sinapis arvensis are well identified weeds of different cropping systems. Quantitative information on regarding seed production by them is limited. Such information is necessary to model dynamics of soil seed banks. The aim of this work was to quantify seed production as a function of the size of those weeds. A wide range of plant size was produced by using a fan seeding system performed at two sowing dates (environments). Plant size varied from 3 to 167 g per plant for canola and from 6 to 104 g per plant for S. arvensis. Seed production ranged from 543 to14,773 seeds per plant for canola, and from 264 to 10,336 seeds per plant for S. arvensis. There was a close relationship between seed production per plant and plant size which was well-described by a power function (y = 130.6x0.94; R² = 0.93 for canola and y = 28x1.27; R² = 0.95 for S. arvensis). There was also strong relationships among the number of pods produced in individual plants and the quantity of seeds produced (g per plant) with the size of the plant. The relationships found in this study can be used in dynamic seed bank models of volunteer canola and S. arvensis.

scholarly journals Broccoli production depending on the seed production system and organic and mineral fertilizer

2012 ◽  
Vol 30 (1) ◽  
pp. 143-150 ◽  
Author(s):  
José Carlos Lopes ◽  
Janaína Mauri ◽  
Adésio Ferreira ◽  
Rodrigo S Alexandre ◽  
Allan R de Freitas
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Seed Production ◽  
Production System ◽  
Aerial Part ◽  
Dry Mass ◽  
Mineral Fertilization ◽  
Espírito Santo ◽  
Fresh And Dry Mass ◽  
Espirito Santo

The experiment was conducted in a greenhouse at the Universidade Federal do Espirito Santo, in Alegre, Espirito Santo state, Brazil, to evaluate the broccoli production depending on the seed production system and organic and mineral fertilization. Seeds of the broccoli cultivar Ramoso Piracicaba were originated from lots of seed obtained in an organic and conventional production system. The experimental design was of randomized blocks, with four replications in a factorial arrangement combination of the lots, 2x5 (organic and mineral fertilized seeds) and substrates [S1 (soil + sand + manure), S2 (soil + sand + manure + NPK), S3 (soil + sand + manure + Fertium® 10 g L-1), S4 (soil + sand + manure + Fertium® 30 g L-1) and S5 (soil + sand + manure + Fertium® 50 g L-1]. The analyzed variables were emergency, fresh and dry mass of aerial part, emergency speed and height of seedlings after 28 days of sowing, and plant diameter, leaf area, number of leaves, fresh and dry mass of aerial part, plant height, root volume, fresh and dry root mass, absolute and relative growth rates and increment to leaf area and plant height after 104 days. The emergency was similar in the different substrates; great vigor occurred on conventional seeds; the mineral fertilization increased the production of fresh mass of aerial part; the use of substrate containing soil, sand soil conditioner Fertium (30 to 50 g L-1) increased the volume, fresh and dry mass of roots and rate of increase in these variables.

scholarly journals Effect of Planting Time on Canopy Structure and Biomass Production in Some Soybean Genotypes

1970 ◽  
pp. 25-29
Author(s):  
MK Uddin ◽  
MK Hasan ◽  
AKMA Alam
Keyword(s):  
Plant Height ◽  
Biomass Production ◽  
Dry Matter ◽  
Canopy Structure ◽  
Morphological Structure ◽  
Dry Weight ◽  
Shoot Biomass ◽  
Late Planting ◽  
Planting Time ◽  
Soybean Genotypes

A field experiment was conducted in the Field Laboratory of the Department of Crop Botany, BAU, Mymensingh during November 2003 to May 2004 to assess the effect of planting time (November and December) on some morphological structure, and root & shoot biomass production in four soybean genotypes (GPB-1, GPB-2, AGS-332 and AGS-11-35). The plant height, stem base diameter, seed dry weight plant-1 were significantly greater in the late planting crops (December) but number of branches plant-1, number of leaves plant-1, leaves dry weight plant-1, shoots dry weight plant-1, roots dry weight plant-1, total dry matter plant-1 were also significantly greater in November planting. Highest plant height, branches plant-1 and leaves plant-1, shoot dry weight plant-1 and total dry matter were found in GPB-2 genotype. Key words: Early and late planting, shoot and root mass, Glycine max. DOI = 10.3329/jard.v5i1.1453 J Agric Rural Dev 5(1&2), 25-29, June 2007

scholarly journals Rhizobacteria inoculation in maize associated with nitrogen and zinc fertilization at sowing

2021 ◽  
Vol 25 (2) ◽  
pp. 96-100
Author(s):  
Andréia de L. Moreno ◽  
Jorge F. Kusdra ◽  
Angelita A. C. Picazevicz
Keyword(s):  
Bacillus Subtilis ◽  
Nitrogen Content ◽  
Plant Height ◽  
Nitrogen Fertilization ◽  
Azospirillum Brasilense ◽  
Dry Weight ◽  
Stem Diameter ◽  
Wide Range ◽  
Maize Plants ◽  
Total Dry Weight

ABSTRACT Rhizobacteria have a wide range of plant growth-promoting mechanisms of action, making them an alternative and/or complementary biological input for chemical fertilizers. In this respect, the present study aimed to assess growth and nitrogen accumulation in maize plants as a function of Azospirillum brasilense, Bacillus subtilis, zinc and nitrogen application at sowing. The experiment with the ‘AL Bandeirante’ maize variety was conducted in a greenhouse, using a completely randomized design. The treatments were arranged in a 2 x 2 x 2 x 2 factorial scheme, with six repetitions, considering the presence and absence of Azospirillum brasilense (5 g kg-1), Bacillus subtilis (5 mL kg-1) and zinc (20 g kg-1) in the seeds and addition or not of nitrogen (30 kg ha-1) to the soil. The variables assessed were plant height, stem diameter, leaf, stem, shoot, root and total dry weight, and shoot nitrogen content. Nitrogen fertilization in the absence of zinc increased shoot and total dry weight as well as shoot nitrogen content. Zinc applied to the seeds improved the total and stem dry weight of maize plants in the absence of Bacillus subtilis. Inoculation with Azospirillum brasilense and Bacillus subtilis increased the stem diameter and shoot nitrogen content of maize plants when nitrogen fertilization was not performed at sowing. There was no isolated or interaction effect between factors for plant height and root dry weight.

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