Modeling Population Dynamics of Kochia (Bassia scoparia) in Response to Diverse Weed Control Options

Weed Science ◽  
2019 ◽  
Vol 67 (1) ◽  
pp. 57-67 ◽  
Author(s):  
O. Adewale Osipitan ◽  
J. Anita Dille ◽  
Muthukumar V. Bagavathiannan ◽  
Stevan Z. Knezevic
Keyword(s):  
Population Dynamics ◽  
Population Growth ◽  
Weed Control ◽  
Seed Production ◽  
Seedling Recruitment ◽  
Control Strategies ◽  
Effective Control ◽  
Parameter Estimates ◽  
Herbicide Resistant

AbstractKochia [Bassia scoparia(L.) A. J. Scott] is a problematic weed species across the Great Plains, as it is spreading fast and has developed herbicide-resistant biotypes. It is imperative to understand key life-history stages that promote population expansion ofB. scopariaand control strategies that would provide effective control of these key stages, thereby reducing population growth. Diversifying weed control strategies has been widely recommended for the management of herbicide-resistant weeds. Therefore, the objectives of this study were to develop a simulation model to assess the population dynamics ofB. scopariaand to evaluate the effectiveness of diverse weed control strategies on long-term growth rates ofB. scopariapopulations. The model assumed the existence of a glyphosate-resistant (GR) biotype in theB. scopariapopulation, but at a very low proportion in a crop rotation that included glyphosate-tolerant corn (Zea maysL.) and soybean [Glycine max(L.) Merr.]. The parameter estimates used in the model were obtained from various ecological and management studies onB. scoparia. Model simulations indicated that seedling recruitment and survival to seed production were more important than seedbank persistence forB. scopariapopulation growth rate. Results showed that a diversified management program, including glyphosate, could provide excellent control ofB. scopariapopulations and potentially eliminate already evolved GRB. scopariabiotypes within a given location. The most successful scenario was a diverse control strategy that included one or two preplant tillage operations followed by preplant or PRE application of herbicides with residual activities and POST application of glyphosate; this strategy reduced seedling recruitment, survival, and seed production during the growing season, with tremendous negative impacts on long-term population growth and resistance risk inB. scoparia.

Simulation Analysis of Weed Population Dynamics in Ridge-Tilled fields

Weed Science ◽  
1993 ◽  
Vol 41 (3) ◽  
pp. 468-474 ◽  
Author(s):  
Nicholas Jordan
Keyword(s):  
Population Dynamics ◽  
Weed Control ◽  
Seed Production ◽  
Simulation Analysis ◽  
Growth Zone ◽  
Effective Control ◽  
Long Term Effects ◽  
Seed Survival ◽  
Weed Population ◽  
Weed Population Dynamics

Effects of nonchemical weed control on weed and seedbank demography in ridge-tilled fields were simulated to examine long-term effects on weed population dynamics. Ridge tillage entails active seedbank management, including removal of much of the seedbank from the crop growth zone (ridge) to the interridge zone (furrow) at planting, and other seedbank manipulations. Dynamics of simulated yellow foxtail and velvetleaf populations were sharply sensitive to the rate of seed removal from the ridge. Variation in winter seed survival, ridge plant demography (emergence, survival, and seed production), and seed survival in the furrow after removal from the ridge also had strong effects on simulated dynamics. To prevent rapid population growth in a simulated corn-soybean rotation, very effective control of seedlings emerging with each crop was necessary to offset seed production from seedlings emerging after ridge rebuilding in corn years. Dynamics of both species were highly sensitive to cultivation efficiency. Effective “rescue” weed control must be available to prevent sharp increases in weed seedbanks during years when cultivation is ineffective.

Herbicide programs to manage glyphosate/dicamba-resistant kochia (Bassia scoparia) in glyphosate/dicamba-resistant soybean

2020 ◽  
Vol 34 (4) ◽  
pp. 568-574
Author(s):  
Ramawatar Yadav ◽  
Vipan Kumar ◽  
Prashant Jha
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Great Plains ◽  
Field Experiments ◽  
Control Strategies ◽  
Effective Control ◽  
The Us ◽  
Herbicide Programs ◽  
Us Great Plains

AbstractEvolution of kochia resistance to glyphosate and dicamba is a concern for growers in the US Great Plains. An increasing use of glyphosate and dicamba with the widespread adoption of glyphosate/dicamba-resistant (GDR) soybean in recent years may warrant greater attention. Long-term stewardship of this new stacked-trait technology will require the implementation of diverse weed control strategies, such as the use of soil-residual herbicides (PRE) aimed at effective control of GDR kochia. Field experiments were conducted in Huntley, MT, in 2017 and 2018, and Hays, KS, in 2018 to determine the effectiveness of various PRE herbicides applied alone or followed by (fb) a POST treatment of glyphosate plus dicamba for controlling GDR kochia in GDR soybean. Among PRE herbicides tested, sulfentrazone provided complete (100%), season-long control of GDR kochia at both sites. In addition, PRE fb POST programs tested in this study brought 71% to 100% control of GDR kochia throughout the season at both sites. Pyroxasulfone applied PRE resulted in 57% to 70% control across sites at 9 to 10 wk after PRE (WAPRE). However, mixing dicamba with pyroxasulfone improved control up to 25% at both sites. Kochia plants surviving pyroxasulfone applied PRE alone produced 2,530 seeds m−2 compared with pyroxasulfone + dicamba (230 seeds m−2) at the Montana site. No differences in soybean grain yields were observed with PRE alone or PRE fb POST treatments at the Montana site; however, dicamba, pyroxasulfone, and pendimethalin + dimethenamid-P applied PRE brought lower grain yield (1,150 kg ha−1) compared to all other tested programs at the Kansas site. In conclusion, effective PRE or PRE fb POST (two-pass) programs tested in this research should be proactively utilized by the growers to manage GDR kochia in GDR soybean.

Introduction to pertussis transmission and epidemiological dynamics

Pertussis ◽  
2018 ◽  
pp. 6-25
Author(s):  
Pejman Rohani ◽  
Samuel V. Scarpino
Keyword(s):  
Control Strategies ◽  
Age Distribution ◽  
Population Level ◽  
Vaccine Uptake ◽  
Effective Control ◽  
Transmission Potential ◽  
Epidemic Period ◽  
The Impact ◽  
Pertussis Epidemiology

Resolving the long-term, population-level consequences of changes in pertussis epidemiology, arising from bacterial evolution, shifts in vaccine-induced immunity, or changes in surveillance, are key challenges for devising effective control strategies. This chapter reviews some of the key features of pertussis epidemiology, together with the underlying epidemiological principles that set the context for their interpretation. These include the relationship between the age distribution of cases and pertussis transmission potential, the impact of vaccine uptake on incidence, periodicity and age incidence, as well as spatially explicit recurrent pertussis epidemics and associated extinction frequency. This review highlights some of the predictable and consistent aspects of pertussis epidemiology (e.g. the systematic increase in the inter-epidemic period with the introduction of whole-cell vaccines) and a number of important heterogeneities, including variations in contemporary patterns of incidence and geographic spread.

Long-term perennial weed control strategies: Economic analyses and yield effect in hazelnut (Corylus avellana)

2016 ◽  
Vol 80 ◽  
pp. 7-14 ◽  
Author(s):  
Emine Kaya-Altop ◽  
Kianoosh Haghnama ◽  
Dogan Sarıaslan ◽  
Colin J. Phillippo ◽  
Husrev Mennan ◽  
...  
Keyword(s):  
Weed Control ◽  
Control Strategies ◽  
Corylus Avellana ◽  
Perennial Weed ◽  
Economic Analyses

Evaluation of Postemergence Weed Control Strategies in Herbicide-Resistant Isolines of Corn (Zea mays)

2006 ◽  
Vol 20 (1) ◽  
pp. 172-178 ◽  
Author(s):  
Karen A. Zuver ◽  
Mark L. Bernards ◽  
James J. Kells ◽  
Christy L. Sprague ◽  
Case R. Medlin ◽  
...  
Keyword(s):  
Weed Control ◽  
Control Strategies ◽  
Post Treatment ◽  
Growth And Yield ◽  
Yield Potential ◽  
Corn Yield ◽  
Corn Hybrids ◽  
Herbicide Resistant ◽  
Giant Ragweed ◽  
Pre Treatment

Herbicide-resistant corn hybrids offer additional options for POST weed control in corn, and growers may benefit from information on the consistency of these weed-control strategies. Studies were conducted in Indiana, Illinois, Michigan, and Ohio, in 2000 and 2001, to evaluate weed control among herbicide strategies for imidazolinone-resistant, glufosinate-resistant, glyphosate-resistant, and conventional corn. Isogenic hybrids were utilized to minimize variation in growth and yield potential among hybrids. The glyphosate-resistant corn postemergence (glyphosate-POST) treatment provided more consistent control of giant foxtail than the PRE, conventional corn postemergence (conventional-POST), glufosinate-resistant corn postemergence (glufosinate-POST), and imidazolinone-resistant corn postemergence (imi-POST) treatments. All four POST treatments were more consistent and provided greater control than the PRE treatment of the large-seeded broadleaf weeds velvetleaf, giant ragweed, common cocklebur, and morningglory species. Conventional-POST and imi-POST were more consistent than glufosinate-POST and glyphosate-POST treatments in controlling giant ragweed. There were no statistical differences in the variability of PRE or POST treatments for control of common lambsquarters, common ragweed, and redroot pigweed. Corn yield varied among locations and years. The glyphosate-POST treatment did not reduce yield relative to the weed-free treatment, the imi-POST and glufosinate-POST treatments each reduced yield in one of eight locations, and the conventional-POST treatment reduced yield in three of eight locations.

Biology of Tropical Soda Apple (Solanum viarum) an Introduced Weed in Florida

1994 ◽  
Vol 8 (3) ◽  
pp. 465-469 ◽  
Author(s):  
J. Jeffrey Mullahey ◽  
John Cornell
Keyword(s):  
Plant Growth ◽  
Weed Control ◽  
Control Strategies ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Effective Control ◽  
Apple Seedling ◽  
Root Segments ◽  
Tropical Soda Apple ◽  
Solanum Viarum

Understanding the biology of tropical soda apple (TSA) is necessary to develop effective control strategies. Tropical soda apple seedling emergence, growth, and regeneration from roots were evaluated. Plant growth (height, leaf number, flowering) was monitored over 110 d in a greenhouse experiment. Emerged seedlings required 83 d to reach a height of 40 cm and 108 d to flower. Total nonstructural carbohydrate concentrations in TSA root and stem fractions, monitored monthly for 1 yr, were highest in December (35%-root, 18%-stem). Seedling emergence as affected by planting depth (0, 1, 2, 4, 8 cm) and regeneration from root segments (7.5, 15 cm long) placed on the soil surface and 5 and 10 cm deep were studied in separate greenhouse experiments. Seedling emergence was lowest (P < 0.05) for seed placed on the soil surface (6.9%) and at a depth of 8 cm (19.4%) with the highest level of TSA emergence predicted at 63% for seed planted 3.6 cm deep. Regeneration from roots was higher (P < 0.05) for the 15-cm root segments than for the 7.5-cm segments while depth of root segment placement did not affect regeneration. Weed control strategies should involve cultural and chemical practices that affect both roots and seeds.

Prospects of Biodiversity in Herbicide-Resistant Crops

2002 ◽  
Vol 31 (3) ◽  
pp. 193-198 ◽  
Author(s):  
Gesine Schütte
Keyword(s):  
Weed Control ◽  
Large Scale ◽  
Control Strategies ◽  
Field Tests ◽  
Environmental Benefits ◽  
Toxicological Effects ◽  
Farming Practice ◽  
Large Scale Field ◽  
Vegetation Surveys

Long-term and large-scale field tests with different weed control methods and agricultural vegetation surveys provide an appropriate tool for an evaluation of the effects on biodiversity of different weed control strategies. In this paper, the toxicological effects, amounts and frequencies of applications, and changes in farming practice are described and compared. The test results are discussed in relation to the question of whether environmental benefits can be achieved by the herbicide-resistance technique. Cropping history and the absence of beneficial plant species invading from the vicinity often override the effects of actual farming practice. Thus long-term strategies are necessary in order to increase biodiversity.

Sustainable long-term weed control strategies with glyphosate programs in hazelnut (Corylus avellanaL.) orchards in Turkey

2018 ◽  
pp. 315-322
Author(s):  
H. Mennan ◽  
I. Brants ◽  
J. Costa ◽  
E. Kaya-Altop ◽  
K. Haghnama
Keyword(s):  
Weed Control ◽  
Control Strategies

Biological Control of Northern Jointvetch (Aeschynomene virginica) in Rice (Oryza sativa) and Soybeans (Glycine max) — a Researcher's View

Weed Science ◽  
1986 ◽  
Vol 34 (S1) ◽  
pp. 17-23 ◽  
Author(s):  
Roy J. Smith
Keyword(s):  
Biological Control ◽  
Acetic Acid ◽  
Oryza Sativa ◽  
Glycine Max ◽  
Weed Control ◽  
Control Strategies ◽  
Effective Control ◽  
Propanoic Acid ◽  
Herbicide Treatments ◽  
The U.S

Weed control strategies for rice (Oryza sativaL.) and soybean [Glycine max(L.) Merr.] emphasize integration of cultural and chemical practices (16, 30, 31). Numerous herbicides are registered and used as preplant, preemergence, or post-emergence applications for control of weeds in rice and soybean (3, 16, 25). Although these herbicide treatments control most of the problem weeds in rice and soybean, most fail to control northern jointvetch [Aeschynomene virginica(L.) B.S.P. # AESVI] in either crop. The two most effective herbicides, 2,4,5-T [2-(2,4,5-trichlorophenoxy) acetic acid] and silvex [2-(2,4,5-trichlorophenoxy) propanoic acid], for control of northern jointvetch in rice have been under the U.S. Environmental Protection Agency's (EPA) Rebuttal Presumption Against Registration (RPAR) process which may ultimately cancel the use of both herbicides in rice (50). New, effective control strategies are needed for control of northern jointvetch in rice and soybean.

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