SIMULATION OF INTEGRATED CONTROL STRATEGIES FOR OROBANCHE SPP. BASED ON A LIFE CYCLE MODEL

A computer simulation model was developed to investigate strategies for control of the parasitic weed species of Orobanche. The model makes use of data from published literature and predicts infestation levels in a dynamic and deterministic way. It is predicted that sustainable control of the parasite can only be achieved by reducing the soil seed bank to levels of 1000–2000 seeds m−2 and maintaining it at that level in subsequent years. When cultural control methods such as hand weeding, trap/catch cropping, delayed planting, resistant cultivars and solarization were considered individually, a relatively high level of effectiveness was required to contain the soil seed bank. An integrated approach with a selection of appropriate cultural methods is therefore recommended for further testing and validation in the field. The simulations demonstrate the importance of preventing new seeds entering the soil seed bank and that although reducing the soil seed bank may not increase yield for the first few years, it will ultimately increase production.

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Relation between Soil Weed Seedbank and Weed Management Practises and Diversity in Farms in Kisii Central Sub County, Nyanza

Journal of Horticulture and Plant Research ◽

10.18052/www.scipress.com/jhpr.10.1 ◽

2020 ◽

Vol 10 ◽

pp. 1-14

Author(s):

Charles N. Nyamwamu ◽

Rebecca Karanja ◽

Peter Mwangi

Keyword(s):

Seed Bank ◽

Weed Management ◽

Management Practices ◽

Soil Seed Bank ◽

Shannon Index ◽

Weed Seed ◽

Weed Species ◽

Western Kenya ◽

Weed Diversity ◽

Hand Weeding

This study sought to determine the relation between soil weed seed bank and weed management practices and diversity in farms in Kisii Central Sub County, Western Kenya. Eight administrative sub-locations were randomly selected. Ten farms were selected at equal distance along transect laid across each sub-location. Weed soil seed bank was assessed from soil samples collected from each of the farms; a sub-sample was taken from a composite sample of ten soil cores of 5cm diameter and 15cm deep and placed in germination trays in a greenhouse. Weed diversity in soil weed seedbank was calculated using the Shannon index (H’). Twelve weed species from 12 genera of nine families were recorded. Diversity of the weed species in soil weed seed bank was (H'=1.48). Weed management practises significantly affected weed species soil weed seedbank reserves. Use of inefficient and ineffective hand-weeding techniques resulted in high weed species diversity and abundance.

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Optimisation of control strategies for the urban wastewater system - an integrated approach

Water Science & Technology ◽

10.2166/wst.1999.0479 ◽

1999 ◽

Vol 39 (9) ◽

pp. 209-216 ◽

Cited By ~ 10

Author(s):

Manfred Schütze ◽

David Butler ◽

M. Bruce Beck

Keyword(s):

Control Strategies ◽

Integrated Control ◽

Water Quality Management ◽

Treatment Plant ◽

Integrated Approach ◽

Urban Wastewater ◽

Sewer System ◽

Integrated Simulation ◽

Case Study Site

Currently, the sewer system, treatment plant and receiving water body are normally considered as separate units in water quality management. The study reported in this paper analyses the potential of integrated control of the urban wastewater system in its entirety. Assembly and implementation of an integrated simulation and optimisation tool, named SYNOPSIS, are presented. This software package allows water quantity and quality processes in the urban wastewater system to be simulated. Furthermore, optimisation modules included in this tool can be applied for off-line optimisation of control strategies. This procedure is exemplified for a semi-hypothetical case study site. Results obtained for this case study suggest that integrated control of the urban wastewater system can indeed lead to some improvement of its performance. This study demonstrates that a tool is now available for assessment of the potential of integrated control.

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Survey Results on Environmental Issues and Weed Science Research Priorities within the Corn Belt

Weed Technology ◽

10.1017/s0890037x00037684 ◽

1993 ◽

Vol 7 (3) ◽

pp. 763-770 ◽

Cited By ~ 18

Author(s):

Edward W. Stoller ◽

Loyd M. Wax ◽

David M. Alm

Keyword(s):

Weed Control ◽

Control Strategies ◽

Research Priorities ◽

Environmental Issues ◽

Science Research ◽

Life Cycles ◽

Cultural Control ◽

Corn Belt ◽

Weed Species ◽

Weed Science

A survey determined the views of individuals in seven groups comprising the weed science community in the corn belt (primarily in Illinois) for importance of 8 environmental and 14 crop production issues and 16 weed species in setting weed science research priorities for the next 3 to 5 yr. The survey also considered if funding of research to solve these environmental and production issues should be from the private or public sector. Velvetleaf, foxtail species, and common lambsquarters were considered the top three weed species by all respondents, and each of these weeds was among the five most important weeds within each of the seven survey groups. Improving ground and surface water quality were the foremost environmental issues for all respondents, but soybean growers listed herbicide carryover as their top environmental concern. Reducing herbicide residues in food and developing sustainable practices were given low preference by all groups. Sustainable growers rated reducing herbicide carryover and minimizing applicator exposure as their lowest priorities. Among all respondents, the top three production issues were improved weed control in conservation tillage, more economical weed control, and improved integrated control strategies. Studying the biology/life cycles of weeds was the third highest production priority of University and U.S. Department of Agriculture (USDA) weed scientists, but was the last choice when averaged over the aggregate survey group. Developing strategies for resistant weeds and herbicide-resistant crops were chemical dealers top two priorities. Industry representatives gave the former subject their highest rating and the latter their lowest rating. Crop consultants seemed to want decision aids, as they chose assessing weed loss/thresholds and developing weed control/economic models among their top three production issues. Both corn and soybean growers desired more economical weed control as a first choice, while sustainable growers wanted improved cultural control strategies. Corn and soybean growers ranked developing new herbicides among their top three choices, but this issue was the lowest choice of the sustainable growers. University, USDA, and industrial weed scientists suggested that their own organizations conduct the research on their highest priorities issues.

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The seed bank of a gallery forest in Southeastern Brazil

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132004000500015 ◽

2004 ◽

Vol 47 (5) ◽

pp. 793-797 ◽

Cited By ~ 16

Author(s):

Maria Tereza Grombone-Guaratini ◽

Hermógenes de Freitas Leitão Filho ◽

Paulo Yoshio Kageyama

Keyword(s):

Community Composition ◽

Forest Fragmentation ◽

Seed Bank ◽

Soil Seed Bank ◽

Southeastern Brazil ◽

Gallery Forest ◽

Weed Species ◽

Wet Season ◽

Important Variation ◽

Number Of Seeds

The soil seed bank was studied in a gallery forest in Southeastern Brazil. Samples were collected from edge to edge along transects perpendicular to the river during the wet (December, 1990) and dry (August, 1991) seasons. The number of seeds found in the seed bank samples was greater in the dry season than in the wet season indicating that there was important variation in the seed stocks in these two periods. The similarity values between the seed bank and the community composition were low. The high density of weed species might be reflecting forest fragmentation and indicating a degree of perturbation.

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Weed Seed Population Response to Tillage and Herbicide Use in Three Irrigated Cropping Sequences

Weed Science ◽

10.1017/s0043174500051390 ◽

1990 ◽

Vol 38 (6) ◽

pp. 511-517 ◽

Cited By ~ 50

Author(s):

Daniel A. Ball ◽

Stephen D. Miller

Keyword(s):

Seed Bank ◽

Soil Seed Bank ◽

Weed Seed ◽

Weed Species ◽

Pronounced Increase ◽

Common Lambsquarters ◽

Hairy Nightshade ◽

Redroot Pigweed ◽

Cropping Sequence ◽

Herbicide Use

Research was conducted to evaluate the effects of primary tillage (moldboard plowing and chisel plowing), secondary tillage (row cultivation), and herbicides on weed species changes in the soil seed bank in three irrigated row cropping sequences over a 3-yr period. The cropping sequences consisted of continuous corn for 3 yr (CN), continuous pinto beans for 3 yr (PB), and sugarbeets for 2 yr followed by corn in the third year (SB). A comparison between moldboard and chisel plowing indicated that weed seed were more prevalent near the soil surface after chisel plowing. The density of certain annual weed seed over the 3-yr period increased more rapidly in the seed bank after chisel plowing compared to moldboard plowing. Species exhibiting the most pronounced increase included hairy nightshade and stinkgrass in the PB cropping sequence and redroot pigweed and common lambsquarters in the SB sequence. Conversely, kochia seed density in the SB sequence decreased more rapidly in chisel-plowed plots. Row cultivation generally reduced seed bank densities of most species compared to uncultivated plots. Herbicide use in each cropping sequence produced a shift in the weed seed bank in favor of species less susceptible to applied herbicides. In particular, seed of hairy nightshade became prevalent in the PB cropping sequence, and seed of kochia, redroot pigweed, and common lambsquarters became prevalent in the SB sequence.

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Soil seed bank of plant species as a function of long-term soil management and sampled depth

Planta Daninha ◽

10.1590/s0100-83582011000400002 ◽

2011 ◽

Vol 29 (4) ◽

pp. 725-736 ◽

Cited By ~ 5

Author(s):

G Concenço ◽

J.C Salton ◽

R.C Brevilieri ◽

P.B Mendes ◽

M.L Secretti

Keyword(s):

Seed Bank ◽

Soil Seed Bank ◽

Soil Management ◽

Field Capacity ◽

Dry Mass ◽

Conventional Tillage ◽

Management Systems ◽

Weed Species ◽

Tillage System

This study aimed at assessing the level of weed infestation indifferent areas that were submitted to different soil management for 16 years. Four management systems were studied: (1) agriculture only under conventional tillage system; (2) agriculture only under no-till system; (3) crop-livestock integrationcrop-livestock integration; (4) livestock only. These areas were sampled at three soil depths (0-5, 5-10 and 10-15 cm), and soil was stored in plastic pots and taken to a greenhouse, where soil moisture and weight were standardized. Soil was kept near 70% moisture field capacity, being revolved every 20 days when all seedling emerged from soil were counted, identified and collected for dry mass assessment. The soil coverage by weeds, number of weed seedlings and dry mass of the weedy community were assessed. A phytoecological analysis was conducted. Weed composition is differentdifferent among management systems after 16 years. Areas with livestock showed much smaller number of weed species in comparison to systems where only grain crops are grown. The presence of livestock affects the potential of germination of soil seed bank. Agriculture systems are similar in terms of weed composition along soil profile, while systems involving livestock show little relation in what regards such sampled depths. Conservationist models of land exploration contribute to reduce severity of weed species occurrence in the long term.

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Weeds occurrence and importance under distinct intercropping systems

Planta Daninha ◽

10.1590/s0100-83582011000400011 ◽

2011 ◽

Vol 29 (4) ◽

pp. 811-819

Author(s):

G Concenço ◽

G Ceccon ◽

F Schwerz ◽

I.C Fonseca ◽

L.F Leite

Keyword(s):

Seed Bank ◽

Yield Loss ◽

Soil Seed Bank ◽

Weed Species ◽

Short Term ◽

Control Practice ◽

Weed Communities ◽

Weed Infestation

Intercropping systems involving corn are often subjected to stress caused by weeds, which usually result in 30-70 per cent yield loss when no control practice is applied. This study aimed to assess the composition of weed communities due to soil coverage, at neighboring areas submitted to distinct soil managements. The soil was collected at field and the study was conducted under a greenhouse in three steps: (1) weeds composition and importance within each treatment; (2) comparison between treatments (distinct crop and intercropping managements); (3) infestation in the area as a whole. The weed composition in the short term is influenced by the management of the area, but this shift requires some more years to be reflected at the soil seed bank. Some weed species occur in high densities and even this way they may not be the most serious weed species present in a given field. Just a few species are adapted to a given system of management in a level enough to be a troublesome weed. Areas differed in relation to weed infestation as a function of management adopted and number of years the new management was applied.

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Effects of Conservative Tillage and Nitrogen Management on Weed Seed Bank after a Seven-Year Durum Wheat—Faba Bean Rotation

Plants ◽

10.3390/plants7040082 ◽

2018 ◽

Vol 7 (4) ◽

pp. 82 ◽

Cited By ~ 5

Author(s):

Mariano Fracchiolla ◽

Anna Stellacci ◽

Eugenio Cazzato ◽

Luigi Tedone ◽

Salem Alhajj Ali ◽

...

Keyword(s):

Durum Wheat ◽

Seed Bank ◽

Faba Bean ◽

Soil Seed Bank ◽

Management Strategies ◽

Nitrogen Supply ◽

Stepwise Discriminant Analysis ◽

Conyza Canadensis ◽

Weed Species ◽

Tillage Systems

Conservative agriculture includes a range of management strategies with low energy inputs such as no-tillage, minimum tillage, and low application of fertilizers. Weed flora in arable fields is strictly affected by agronomic practices such as tillage and fertilization management. This study was conducted seven years after the beginning of a long-term—durum wheat–faba bean—rotation. It analyzes the combined effects on the soil seed bank of three different tillage systems (conservative, reduced, and conventional tillage) and two levels of nitrogen fertilization. The effects were investigated both using stepwise discriminant analysis and analysis of variance in order to find statistical differences among main factors and their interactions. The seed bank of Conyza canadensis, Papaver rhoeas, Solanum nigrum, Fallopia convolvulus, and Fumaria officinalis was higher in conservative or reduced tillage plots. The magnitude of the response to nitrogen supply varied among weed species. Conyza canadensis seemed to be favored by low nitrogen supply, whereas Sinapis arvensis by higher doses of nitrogen. Anagallis arvensis showed the lowest seed bank in conventionally tilled plots, without distinction of nitrogen supply. The results suggest that different tillage systems and, to a lesser extent, different nitrogen supply, produce changes in the seed bank size and composition, along the soil profile.

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Weed Seed Pools Concurrent with Corn and Soybean Harvest in Illinois

Weed Science ◽

10.1614/ws-07-195.1 ◽

2008 ◽

Vol 56 (4) ◽

pp. 503-508 ◽

Cited By ~ 9

Author(s):

Adam S. Davis

Keyword(s):

Seed Bank ◽

Soil Seed Bank ◽

Soil Surface ◽

Seed Rain ◽

Weed Seed ◽

Weed Species ◽

East Central ◽

Giant Foxtail ◽

Central Illinois ◽

Prickly Sida

At the time of grain harvest, weed seeds can be classed into one of four pools on the basis of dispersal status and location: (1) undispersed, remaining on the mother plant; (2) dispersed in the current year, on the soil surface; (3) dispersed in the current year and collected by harvest machinery; and (4) dispersed in a previous year and persisting within the soil seed bank. Knowledge of the relative sizes of these seed pools for different weed species under different crop environments will be useful for determining the best way to reduce the size of inputs to the soil seed bank. In fall 2004 and fall 2005, four randomly selected commercially managed corn and soybean fields in east-central Illinois were sampled to quantify weed seed pools at time of crop harvest. Thirty randomly located 0.125-m2quadrats were placed within each field, the four seed pools mentioned above were sampled for each quadrat, and the species composition and abundance of each seed pool was determined. The magnitude of the weed seed rain varied among species and between years and crops. Twenty-six weed species were found to contribute to at least one of the four seed pools. However, the weed seed pools were consistently dominated by six species: velvetleaf,Amaranthuscomplex (redroot pigweed and waterhemp), ivyleaf morningglory, giant foxtail, prickly sida, and common cocklebur. For each of these species, the ratio of undispersed seeds to seeds in the soil seed bank at harvest time was ≥ 1 in at least one crop during one of the two experimental years, indicating a potential for the soil seed bank to be completely replenished or augmented by that year's seed rain. This analysis demonstrates the urgent need for techniques to limit weed seed inputs to the soil seed bank at the end of the growing season.

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Innovative Control Strategies for the Diagnosis of Injector Performance in an Internal Combustion Engine via Turbocharger Speed

Energies ◽

10.3390/en12081420 ◽

2019 ◽

Vol 12 (8) ◽

pp. 1420 ◽

Cited By ~ 1

Author(s):

Michele Becciani ◽

Luca Romani ◽

Giovanni Vichi ◽

Alessandro Bianchini ◽

Go Asai ◽

...

Keyword(s):

Combustion Engine ◽

Control Strategies ◽

Integrated Control ◽

Combustion Process ◽

Engine Performance ◽

Operating Conditions ◽

Correct Operation ◽

Control Units ◽

The Right ◽

High Level

In order to ensure a high level of performance and to comply with the increasingly severe limitations in terms of fuel consumption and pollution emissions, modern diesel engines need continuous monitoring of their operating conditions by their control units. With particular focus on turbocharged engines, which are presently the standard in a large number of applications, the use of the average and the instantaneous turbocharger speeds is thought to represent a valuable feedback of the engine behavior, especially for the identification of the cylinder-to-cylinder injection variations. The correct operation of the injectors and control of the injected fuel quantity allow the controller to ensure the right combustion process and maintain engine performance. In the present study, two different techniques are presented to fit this scope. The techniques are discussed and experimentally validated, leading to the definition of an integrated control strategy, which features the main benefits of the two, and is able to correctly detect the cylinder-to-cylinder injection variation and, consequently, properly correct the injection in each cylinder in order to balance the engine behavior. In addition, the possibility of detecting misfiring events was assessed.

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