Weed Eradication Research Articles

PENGARUH BIAYA PRODUKSI TERHADAP PENDAPATAN PETANI MANDIRI KELAPA SAWIT DI KECAMATAN SEGAH

The purpose of this study was to analyze the income of independent oil palm farmers in the Segahdistrict. The analytical tool used are multiple linear regression equations, correlation coefficients, t test and calculated f test
 Based on the results of the analysis, it was found that the multiple linear regression equation influences the cost of seedlings, fertilizer costs and financing the eradication of weeds against the income of independent oil palm farmers in Segah district is Y = - 1,469 + 0,639 X1 + 4,150 x3 . To measure the degree of the correlation between seed costs, fertilizer costs and financing of weed eradication of the income of independent oil palm farmers in Segah district, the researcher used a multiple correlation coefficient (R) = 0.993 which means that the variable costs of seeds, fertilizer costs and weed eradication costs affect the income of farmers independent of oil palm in Segah District, the coefficient of determination R = 0.987 which showed that the income of independent farmers of oil palm in Segah district is influenced by seed costs, fertilizer costs, and weed eradication costs while the remaining 1.13% (1 - 0.987) is a factor which is not examined. Based on testing using f test where f arithmetic is 0.040 <0.10 and t count value is 2.617> 1.943, it can be concluded that the proposed hypothesis is accepted.

Seedsvsfungi: an enzymatic battle in the soil seedbank

AbstractDepleting the soil weed seedbank is an important integrated weed management strategy that has the potential to foster lasting weed control. Long-term dormancy and decay resistance of weed seeds pose a challenge to weed eradication efforts. Select soil fungi have been shown to cause significant decay of weed seeds. The physical and chemical mechanisms by which seeds in the seedbank defend themselves against pathogens have been well researched. However, very few studies have purposefully investigated the biochemical defence response of seeds. Enzyme-based biochemical seed defences have been detected in dormant and non-dormant seeds, and research supports their function in pathogen defence. This review summarizes current knowledge of the seed defence enzymes polyphenol oxidase, peroxidase, chitinase and oxalate oxidase. The fungal enzymes chitinase, protease and xylanase that function in pathogenesis of seeds in the soil seedbank are also reviewed. Progress in the development and standardization ofin situenzyme analyses fosters our understanding of actual enzyme activity present in soils, while high-throughput microplate techniques promote efficiency and enable greater scope. Application of genomic, proteomic and transcriptomic techniques to glean a deeper and more holistic understanding of the enzymatic interactions of weed seeds and soil fungi in the soil seedbank will support the development of improved integrated weed management strategies.

Seeding plants for long-term multiple ecosystem service goals

The historical management of agroecological systems, such as California's rangelands, have received criticism for a singular focus on agricultural production goals, while society has shifting expectations to the supply of multiple ecosystem services from these working landscapes. The sustainability and the multiple benefits derived from these complex social-ecological systems is increasingly threatened by weed invasion, extreme disturbance, urban development, and the impacts of a rapidly changing and increasingly variable climate. California's grasslands, oak savannas, and oak woodlands are among the most invaded ecosystems in the world. Weed eradication efforts are rarely combined with seeding on these landscapes despite support for the inclusion of the practice in a weed management program. Depending on seed mix choice, cost and long-term uncertainty, especially for native seed, is an impediment to adoption by land managers. We investigated four seeding mixes (forage annual, native perennial, exotic perennial, and exotic-native perennial) to evaluate how these treatments resist reinvasion and support the delivery of simultaneous multiple ecosystem services (invasion resistance, native richness, nitrogen fixing plants, pollinator food sources, plant community diversity, forage quality, and productivity). We found the increase of exotic and native perennial cover will drive resistance to an invading weedy summer flowering forb Centaurea solstitialis but provides a mixed response to resisting invasive annual grasses. The resistance to invasion is coupled with little tradeoff in forage productivity and quality and gains in plant diversity and native cover.

Pengaruh Eradikasi Gulma terhadap Perkembangan Populasi Wereng Hijau dan Kejadian Penyakit Tungro pada Padi

Tungro is one of the important diseases in rice that is still a constraint to increased productivity. Tungro disease caused by a tungro viruses that is transmitted by green leafhoppers in a semi persistent manner. The presence of weeds can cause yield losses of rice and is a potential host plant of tungro viruses. Eradication of weeds is an attempt to eliminate the source of inoculum of tungro viruses. The research objective was to determine the effect of weed eradication on the development of green leafhopper population and the incidence of tungro disease. The study was conducted in an experimental field of Tungro Disease Research Station, Lanrang Village, Sidenreng Rappang District, South Sulawesi at rainy season and dry season 2014. The experiment was arranged in a randomized complete block design with 8 eradication treatments and 4 replications. The parameters include the observation of weed species that grow in each plot and embankment planting, green leafhopper population density and the number of infected plants by tungro viruses. Observations in the planting is done at 2, 4, 6, and 8 weeks after planting (WAP). The observations of weeds and green leafhopper population was also conducted on the field before eradication. The results showed that the weeds potential as a source of inoculum were Cyperus rotundus, C. iria, Fimbristylis miliacea, and E. colonum. Eradication of weeds before and after planting through both mechanical and herbicide applications tended to suppress the green leafhopper populations and tungro disease incidence.

Estimating realistic costs for strategic management planning of invasive species eradications on islands

Environmental managers regularly face decisions about how to counteract threats. These decisions require an understanding of both the conservation benefits and economic costs of candidate actions. However, transparent frameworks for how to accurately calculate costs for management are rare. We worked with island managers in Australia to develop eradication protocols for six invasive species- four mammals and two weeds. We used the protocols to create an accounting framework for invasive species eradications to produce realistic cost estimates for eradications across multiple locations. We also used our models to test common cost assumptions: (1) that costs scale linearly with area, (2) that terrain does not influence costs, and (3) that eradication costs stay constant through time. By explicating testing assumptions, we found that costs largely scaled linearly with area, that terrain influences costs, and that costs decline as populations decline in response to ongoing management. Estimated mammal eradication costs were driven in large part by the area of an island and the cost of transport. However, when area alone was used as a proxy for costs, the calculated costs deviated from our modelled costs by 40–56%. Weed eradication cost estimates were driven by the size and density of an infestation as well as the terrain of the island, with the effect of terrain becoming more pronounced as area to be treated increased. We provide a method to calculate realistic costs across several sites, which can be used to guide strategic management decision-making, including prioritisation, and on-ground management actions.

Weed abundance is positively correlated with native plant diversity in grasslands of southern Australia.

Weeds are commonly considered a threat to biodiversity, yet interactions between native and exotic species in grasslands are poorly understood and reported results vary depending on the spatial scale of study, the factors controlled for and the response variables analysed. We tested whether weed presence and abundance is related to declines in biodiversity in Australian grasslands. We employed existing field data from 241 plots along a disturbance gradient and correlated species richness, cover and Shannon diversity for natives and exotics, controlling for seasonal rainfall, climatic gradients and nutrient status. We found no negative relationships in terms of emergent diversity metrics and occupation of space, indeed, many positive relationships were revealed. When split by land-use, differences were found along the disturbance gradient. In high-moderately disturbed grasslands associated with land-uses such as cropping and modified pastures, positive associations were enhanced. Tolerance and facilitation mechanisms may be involved, such as complementary roles through different life history strategies: the exotic flora was dominated mainly by annual grasses and herbs whereas the native flora represented more diverse growth-forms with a higher proportion of perennials. The positive relationships existing between native and exotic plant species in high-moderately disturbed grasslands of South Australia are most likely due to facilitation through different strategies in occupation of space given that the effect of habitat suitability was controlled for by including environmental and disturbance factors. Consequently, although particular weeds may negatively impact biodiversity, this cannot be generalised and management focusing on general weed eradication in grasslands might be ineffectual.

Investigation results of kinematic and dynamic indicators of tiller with vertical rotation axis in orchards soil cultivation

Abstract The results of experimental-theoretical investigations on the tillers with vertical rotation axis in soil cultivation and weed eradication in orchards are introduced in the article. Upon the developed theory of rotary tiller kinematics and dynamics calculation the following points have been set up: − In kinematics – functional dependence of the tiller work of technological and regime parameters enabling a high technological quality of soil weed mass cultivation; − In dynamics – mathematical model of energy evaluation function of soil-weed mass cultivation technological process depending on constructive-regime parameters of the tiller with vertical rotation axis, providing the minimum amount of torque against the resistance towards soil cutting. The reliability of the developed calculation theory has been verified through the results of conducted experiments, the difference hasn't exceeded 5%, which is explained by the inhomogeneity of the treated medium and changeability of the straightness of the garden rows.

A review of 15 years of Spartina management in the San Francisco Estuary

Regional, ecosystem-level conservation projects with significant vegetation management components require planning, coordination, and responsive management strategies to minimize negative impacts and maximize ecological benefits over time. The California State Coastal Conservancy’s Invasive Spartina Project (ISP) offers an example of a complex, ecosystem-scale weed eradication effort guided by regional conservation goals. We review the management framework developed by the ISP, describe decision thresholds used for site-specific management transitions over the project’s 15 years, and present strategies being used to address major challenges to project completion. These strategies include developing genetics and weed mapping approaches to aid with identification of hybrids between the introduced Spartina alterniflora and the native Spartina foliosa. The ISP also developed a tidal marsh restoration project to enhance habitat for an endangered bird, the California Ridgway’s rail (Rallus obsoletus obsoletus), that uses tall, dense forms of hybrid Spartina as high tide refugia and nesting substrate. By 2014, the ISP had installed over 300,000 native plants and recorded a greater than 96 % estuary-wide reduction in hybrid Spartina (from 323 ha to 12 net ha) despite treatment restrictions imposed at 11 sites since 2011 to protect the rail. Approximately 80 % of the remaining hybrid Spartina occurs in areas currently restricted from treatment, delaying project completion. The successes and setbacks of the ISP illustrate the complexities of achieving ecosystem-level conservation goals dependent on large-scale vegetation management.

Recruitment of seedlings versus ramets as affected by pasture degradation in alpine meadows and the implications for ecological restoration

Background: The degradation of alpine meadows on the Qinghai-Tibetan Plateau (QTP) has an impact on vegetation recruitment from seedlings and ramets.Aims: Understanding the relative contribution of recruitment by seedling and ramet in alpine meadows is for the ecological restoration of degraded grasslands on the QTP.Methods: An experiment was conducted to investigate seedling and ramet densities, species composition and their relationships with standing vegetation in plots representative of non-degraded (ND), lightly (LD), moderately (MD) and severely degraded (SD) alpine meadows.Results: With increasing degradation and the reduction in vegetation cover, the number of seedlings and ramets declined. The proportion of young plants arising from seedlings was low, with the majority of species reproducing clonally. The establishment of seedlings of forbs in SD meadows led to species-rich, forb-dominant vegetation in these areas.Conclusions: LD and MD meadows appear to be able to be managed by reduced grazing for the restoration of grass- and sedge-dominated pastures. In contrast, restoration of SD meadows will require additional intervention, such as of seeding and weed eradication.

Weed eradication feasibility: lessons of the 21st century

SummaryThe past decade has seen strong controversy concerning the upper bounds for weed eradication. Over this period, two of the most ambitious weed eradication attempts ever have failed. These have, however, provided rich data sets that have supported a productive and highly collaborative research effort. I review this research and present a new algorithm for assessing eradication feasibility, based upon time to maturation, seedbank persistence and membership of one of two contrasting dispersal functional groups. Eight ‘eradication syndromes’ are identified and their relative eradication feasibilities indicated. The syndrome with the highest feasibility includes species that combine long juvenile periods and low seedbank persistence with short‐distance and/or human‐mediated dispersal. At first glance, this may not be a common syndrome. The syndrome with the lowest feasibility comprises plants that combine a short juvenile period and high seedbank persistence with abiotic or non‐human‐mediated biotic dispersal. It includes a number of aquatic perennials that can be dispersed over large distances by floodwaters. Projected costs for a programme targeting a plant species should reflect its syndrome membership. Improved cost estimates will support better decision‐making with regard to programme initiation, maintenance and termination; models are available that can provide estimates of eradication programme duration and cost. Whether eradication has much of a future as a weed invasion management strategy will likely rest upon more timely, better‐informed and shrewder target selection.

Design, Development and Evaluation of Targeted Discrete-Flame Weeding for Inter-row Weed Control Using Machine Vision

Weed management is a major constraint in organic crop production. The main objectives were design, development and evaluation of a targeted-discrete flame weeder in laboratory and comparing continuous (uniform) flame weeding with targeted flaming of inter-row weeds in an organic maize production field. In the laboratory tests, optimum angle and height of burners, as well as accuracy and precision of the targeted discrete-flamer were evaluated at three levels of ground speed (0.5, 0.7 and 0.9 m s -1 ). In the field experiments, the effects of the same ground speed levels at three maize plant growth stages (4, 6 and 8 leaves denoted by V4, V6 and V8, respectively) on weed eradication as well as on fuel consumption were investigated. The results of the laboratory tests showed that the optimum position of burners were 25 cm above the ground surface and inclined at 30o for achieving acceptable accuracy in application of targeted flaming. In the field trials, uniform (continuous) and targeted (discrete) flaming showed similar results in weed eradication, while fuel consumption of the targeted method was significantly lower than the uniform application. Also, based on the field experiments, weed control calculated three days after flaming (3DAF) was significantly higher than that of one day after flaming (1DAF) and the first flaming was significantly more effective than the second and third flaming. The results of this investigation indicates that targeted-discrete flame weeding by using machine vision technology is a potential alternative to uniform flaming with extra advantages of lower fossil fuel consumption and air pollution.

Fertile transgenic Lotus corniculatus resistant to the non‐selective herbicide phosphinothricin

AbstractResistance to the non‐selective herbicide dl‐phosphinothricin (PPT) was introduced into commercial Lotus corniculatus cv. Bokor by co‐cultivation of cotyledons with Agrobacterium tumefaciens AGL1 harbouring the binary vector pDM805 which contains the bialaphos resistance gene (bar) from Streptomyces hygroscopicus encoding phosphinothricin acetyltransferase (PAT) and the uidA gene encoding β‐glucuronidase. The half‐cotyledon explants were precultured on regeneration Murashige and Skoog's (MS) medium supplemented with 6‐benzyladenine (BA) and 1‐naphthaleneacetic acid (NAA) at 0.5 mg L−1 each, 3 days prior to infection. Upon co‐cultivation, the explants were cultured on PPT‐free regeneration medium for 10 days, and then subcultured on regeneration/selection media with increasing PPT concentrations (5–7 mg L−1) for about 18 weeks. Out of 480 initially co‐cultivated explants, 272 regenerated shoots survived the entire PPT selection procedure. Resistant shoots were grown further, multiplied by tillering that was additionally promoted by PPT and rooted on hormone‐free MS medium containing 5 mg L−1 PPT. Established shoot cultures, continuously maintained on the same medium, have preserved PPT resistance up to now (more than 2 years). Transformed plants assessed in vitro and in a greenhouse were tolerant to the herbicide PPT at 300 mg L−1 equivalent to more than twofold the recommended field dosage for weed eradication. Applied PPT treatment did not affect the activities of glutamine synthetase (GS; EC 6.3.1.2) and NADH‐dependent glutamate dehydrogenase (NADH‐GDH; EC 1.4.1.2) in transformed plants. However, PPT did increase the mobility of glutamine synthetase isoforms GS1 and GS2 as well as the inhibition of an additional high mobility GS (hmGS) activity. In untransformed plants, PPT treatment reduced total GS activity by 4.4‐fold while contrary the activity of NADH‐GDH was increased by ninefold. All transformed herbicide‐resistant plants were phenotypically normal and exhibited genomic stability, as were the untransformed plants analysed by flow cytometry. Under greenhouse conditions, they grew to maturity, flowered and set seeds. Stable integration and expression of the bar gene in T0 and T1 plants were confirmed by Southern and Western blot analysis, while integration of the reporter uidA gene did not occur. The bar gene was inherited in a Mendelian fashion by the progeny, as detected by PPT resistance. The production of PPT‐resistant plants may have significant practical applications in weed control in fields of L. corniculatus.

English

The major problem faced in agriculture is the weeds and the pests. In order to remove or kill the weeds and the pests, there is a large scale use of weedicides and pesticides that leads to dual expenditure at the cost of crop maintenance. Weeds are rarely considered a priority despite the fact that all the farmers know that majority of their variable costs and time is devoted to eradicate them. The objective of the work was to derive a simple and cheap method to produce a biopesticide from agricultural weeds, in an order which could be used by the farmers. Nineteen weeds were selected, and a biopesticide was produced from them by extraction method. The produced biopesticide was tested in 5 agricultural fields against tea, paddy, maize and cabbage plants. The pesticide was highly effective against aphids, leaf folder disease, thrips, Japanese beetle, army worm and the cutworm caterpillar. The effect of the biopesticide derived from the agricultural weeds was around 50 to 75% more than the conventional chemical based pesticide. The biopesticide produced by this method helps in weed eradication, lowers the cost of crop production and is helpful in getting rid of the harmful effect of chemicals on the entire ecosystem.   Key words: Weed, pest, biopesticide, eco system, agriculture.

Economic aspects of post‐border weed risk management

AbstractAimDecision‐making in weed management involves consideration of limited budgets, long time horizons, conflicting priorities, and as a result, trade‐offs. Economics provides tools that allow these issues to be addressed and is thus integral to management of the risks posed by weeds. One of the critical issues in weed risk management during the early stages of an invasion concerns feasibility of eradication. We briefly review how economics may be used in weed risk management, concentrating on this management strategy.LocationAustralia.MethodsA range of innovative studies that investigate aspects of weed risk management are reviewed. We show how these could be applied to newly invading weeds, focussing on methods for investigating eradication feasibility. In particular, eradication feasibility is analysed in terms of cost and duration of an eradication programme, using a simulation model based on field‐derived parameter values for chromolaena, Chromolaena odorata.ResultsThe duration of an eradication programme can be reduced by investing in progressively higher amounts of search effort per hectare, but increasing search area will become relatively more expensive as search effort increases. When variation in survey and control success is taken into account, increasing search effort also reduces uncertainty around the required duration of the eradication programme.Main conclusionsEconomics is integral to the management of the risks posed by weeds. Decision analysis, based on economic principles, is now commonly used to tackle key issues that confront weed managers. For eradication feasibility, duration and cost of a weed eradication programme are critical components; the dimensions of both factors can usefully be estimated through simulation.

INTEGRATION BETWEEN SOME INSECTICIDE AND REMOVING WEEDS TO CONTROL THE CUTWORMS

Cutworm control was conducted to show the integrated effect between insecticide and weed eradication. Results showed that the insecticide Loresban was significantly more effective in compeer with weed eradication and seed treatment with the insecticide Cruiser in reducing the number of cutting plant, chewing plant leaves & chewing area amount. The best treatment for control was spraying the plants and the soil with Loresban where number of cutting plant was 1.17 plant, chewing plant leaves were 6 & chewing area amount was 8,28 cm2.and the means of control treatment was 4,06 plant, 11,22 leaf, 11,22 cm2 respectively , and it was found significant differences at 5٪ probability between treatments .Eradication progress caused significant reduce in chewing plant leaves number & chewing area amount and it was also showed that the best treatment was pre planting weed eradication and the result was 6.72 chewing plant leaves & 21.18 cm2 chewing area amount. Seed treatment with the insecticide Cruiser reduced the number of cutting plant the lower number with average 1.85, without any effect to other characters.

Effect of plant density ratios and weed control on the performance of maize-bean intercropping

A 2-year study (2010-2011) was carried out in order to evaluate the effects of bean and maize intercropping. The experiment tested five different cropping systems: sole cropping of each crop, as well as intercropping of maize/bean with the ratios of 1:3 (M1B3), 2:2 (M2B2) and 3:1 (M3B1), each of which took place in the presence of two weed management systems (no weed control and weed eradication through manual removal), in a factorial experiment based on randomized complete block design using three replicates. Tests of homogeneity of variance for combined data over two years showed that data of both years could be analyzed together. The results showed that the effect of intercropping treatments on all measured traits in maize and bean were significantly different. A minimum land equivalent ratio (LER) for maize (0.78) was obtained for M3B1 under conditions of no weed control, while the highest LER (1.03) was observed in M3B1 under weed-free conditions. The highest (0.99) and lowest (0.70) LER values for beans were recorded for M1B3 under weed-free conditions and M3B1 under conditions of no weed control, respectively. M1B3 under weed-free conditions showed the highest total LER (2.02), while M3B1 under conditions of no weed control showed the lowest (1.48). Results of this study indicated that intercropping bean and maize can be an effective method to increase total productivity, and that the M1B3 system was the best cropping system for high productivity.

A model for risk‐based assessment of Phelipanche mutelii (branched broomrape) eradication in fields

Prider J, Correll R & Warren P (2012). A model for risk‐based assessment of Phelipanche mutelii (branched broomrape) eradication in fields. Weed Research52, 526–534.SummaryA method is required for evaluating the progress towards eradication for weeds that are difficult to detect and have a persistent seedbank. The objective of this study was to develop a risk assessment model for fields previously infected by the annual parasitic plant, Phelipanche mutelii (branched broomrape). We analysed presence/absence survey data for fields infested by P. mutelii to estimate the proportions of fields that will return a weed infestation at annual intervals after initial detection. Infested fields in South Australia are subject to quarantine and are the focus of a national weed eradication programme. The model predicted that after 12 years of absent surveys, the probability of a single field returning an infestation was 0.01, which declined to 0.001 after 20 years. These probabilities can be used by managers to assess the risk of declaring a field broomrape‐free after a given number of absent surveys. Simulation modelling reveals the first year following initial detection of the weed is crucial for control, as returning fields in this year have a large influence on the length of the eradication programme. It is predicted that complete eradication of the weed could occur in 38–62 years, with the lower limit achievable by maintaining low numbers of returning fields through effective control and containment.

Effect of aqueous extract of sun-dried neem (Azadirachta indica A.) leaves on wheat yield under field condition

A study was conducted to assess the allelopathic effects of aqueous extract of sun-dried neem (Azadirachta indica A) leaves on wheat yield and its components in the agronomic research area, University of Agriculture, Faisalabad. Grain yield and different yield components of wheat, such as number of fertile tillers, grain/spike and 1000-grain weight, and spike length showed no significant either promotive or suppressive effect with the application of 0, 50 and 100% aqueous leaf extract of neem. However, the aqueous leaf extract of neem did not inhibit the wheat yield and yield components. Natural weedicide (aqueous leaf extract of neem) certainly had no polluting effect of chemicals on the wheat quality. Keywords: Allelopathy, aqueous extract of leaves, wheat quality improvement, bio -weed eradication.

Progress toward Environmental Weed Eradication in New Zealand

AbstractData on 111 environmental weed eradication programs carried out by the New Zealand Department of Conservation (DOC) have been collected and summarized. A total of 21 programs were discontinued, and 90 are ongoing. Within the ongoing programs, four have been successful in that no plants remain at any known infestations. All four of the successful eradications had a total area across all infestations of less than 1 ha (2.5 ac); however, many similar-sized programs were not successful. Correctly assessing the extent of infestations appears to be a major problem for discontinued programs. Some of the ongoing programs are progressing toward eradication, but this is taking much longer than initially anticipated. The strongest determinant of progress toward eradication was found to be the identity of the DOC administrative area, for reasons that are only speculative. The number and area of initial infestations had no effect on progress toward eradication. However, the rate at which new infestations were located was negatively correlated with progress. Across many programs, progress was restricted by inconsistent infestation visitation. After running for a decade, DOC's weed eradication strategy has yet to provide significant dividends. Environmental weed eradication is clearly more difficult than has previously been acknowledged in New Zealand.

The U.S. Witchweed Eradication Effort Turns 50: A Retrospective and Look-Ahead on Parasitic Weed Management

The U.S. Witchweed Eradication Effort Turns 50: A Retrospective and Look-Ahead on Parasitic Weed Management