Determining the growth responses of Phyla canescens to shoot and root damage as a platform to better-informed weed-management decisions

2012 ◽  
Vol 60 (4) ◽  
pp. 310 ◽  
Author(s):  
M. H. Julien ◽  
C.-Y. Xu ◽  
A. Bourne ◽  
M. Gellender ◽  
R. De Clerck-Floate
Keyword(s):  
Weed Management ◽  
Management Strategies ◽  
Control Measures ◽  
Control Methods ◽  
Growth Responses ◽  
Severe Damage ◽  
Management Decisions ◽  
Relative Growth ◽  
Apical Buds ◽  
Whole Plants

Understanding the responses of invasive plants to control methods is important in developing effective management strategies. Lippia (Phyla canescens (Kunth) Greene : Verbenaceae) is an invasive, perennial, clonal forb for which few control options exist for use in the Australian natural and agro-ecosystems it threatens. To help inform management decisions, lippia’s growth responses to damage it may experience during proposed control measures, i.e. cutting, crushing, twisting, were assessed in three glasshouse experiments using either whole plants or plant pieces. Plants quickly recovered from severe damage through growth from shoot and root buds at stem nodes. After shoot and root removal, the relative growth rate of the remaining plant was twice that of controls, suggesting tolerance to damage. Lacking buds, root pieces and isolated stem internodes were incapable of responding. Crushing and cutting individual ramets and plant pieces induced the largest responses, including release of axillary buds on damage or removal of apical buds, but full recovery was not achieved. Lippia will be difficult to control because of its ability to rapidly propagate from stem fragments possessing undamaged or damaged nodes; thus, the full impact of control methods that increase fragmentation (e.g. grazing) should be assessed before implementation. Our results also suggest that the most effective biological agents will be those that limit lippia’s vegetative growth and spread, such as shoot- or crown-feeding insects.

scholarly journals The Effect of Different Weed Management Strategies on the Growth and Yield of Direct-Seeded Dry Rice (Oryza sativa)

2016 ◽  
Vol 34 (1) ◽  
pp. 57-64 ◽  
Author(s):  
S. MUHAMMAD ◽  
I. MUHAMMAD ◽  
A. SAJID ◽  
L. MUHAMMAD ◽  
A. MAQSHOOF ◽  
...  
Keyword(s):  
Weed Control ◽  
Crop Yield ◽  
Weed Management ◽  
Management Strategies ◽  
Control Measures ◽  
Growth And Yield ◽  
Primary Concern ◽  
Herbicide Treatment ◽  
Direct Seeded ◽  
Hand Weeding

Weed management is a primary concern in direct seeded rice (DSR) cropping because weed growth becomes a major constraint on crop yield. A two year field study was set up to evaluate the effect of various weed control measures on crop growth, grain yield and grain quality of DSR. The experiment involved five different weed control measures: hand weeding, hoeing, inter-row tine cultivation, inter-row spike hoeing and herbicide treatment (Nominee 100 SC). The extent of weed control (compared to a non-weeded control) ranged from 50-95%. The highest crop yield was obtained using hand weeding. Hand weeding, tine cultivation and herbicide treatment raised the number of fertile rice tillers formed per unit area and the thousand grain weight. Tine cultivation provided an effective and economical level of weed control in the DSR crop.

scholarly journals (416) Weed Management in Organic Sweet Corn

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1071E-1072
Author(s):  
Anthony Silvernail
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Sweet Corn ◽  
Management Strategies ◽  
Organic Production ◽  
Control Methods ◽  
Weed Biomass ◽  
Corn Gluten ◽  
And Control ◽  
Smooth Pigweed

Organic weed control in direct seeded vegetables depends on management strategies that control weed germination or growth which depletes the weed seedbank. In 2004, a randomized complete-block experiment conducted on land transitioning to organic production examined the effects of tillage and control treatments on weed pressure in sweet corn [Zeamays (L.) cv. Silver Queen]. The two tillage treatments consisted of conventional (moldboard and rototill) and spader tillage. Weed control treatments included a weed free control, a spring-tine weeder, rolling cultivator, row flamer, stale seedbed, and corn gluten meal. In August, the weed infestation was primarily goose grass [Eleusineindica (L.) Gaertn.], crab grass [Digitariasanguinalis (L.) Scop.], giant foxtail (Setariafaberi Herrm.), and smooth pigweed [Amaranthushybridus (L.)] species. Dried weed weights indicated that smooth pigweed constituted about 80% of the total weed biomass in all but the control and flamer treatments. Plots managed with the spring-tine weeder or corn gluten had twice the weed biomass of those managed with the rolling cultivator and flamer. The rolling cultivator and control treatments produced equivalent husked corn yields (6.9 t·ha-1); yields were reduced by the other weed control methods. At 5.4 t·ha-1, yields in the flamer treatment were the lowest among all weed control methods. The flamer suppressed both weeds and the crop, which may preclude its utility for sweet corn production. Results demonstrated that the rolling cultivator provided the best weed control without negatively affecting potential yields.

Patterns Of Resistance To Als Herbicides In Smallflower Umbrella Sedge (Cyperus Difformis) And Ricefield Bulrush (Schoenoplectus Mucronatus)

2006 ◽  
Vol 20 (4) ◽  
pp. 1004-1014 ◽  
Author(s):  
Roberto Busi ◽  
Francesco Vidotto ◽  
Albert J. Fischer ◽  
María D. Osuna ◽  
Rafael De Prado ◽  
...  
Keyword(s):  
Weed Management ◽  
Management Strategies ◽  
Acetolactate Synthase ◽  
Cross Resistance ◽  
Cyperus Difformis ◽  
Resistance Patterns ◽  
Evolution Of Resistance ◽  
Whole Plants ◽  
Herbicide Use ◽  
Moderately Resistant

Biotypes of smallflower umbrella sedge and ricefield bulrush resistant to acetolactate synthase (ALS)-inhibiting herbicides have been reported in several rice areas of the world. Here, we present results of a study conducted on whole plants of seven smallflower umbrella sedge and four ricefield bulrush biotypes collected in Italian, Spanish, and Californian rice fields to evaluate cross-resistance to ALS herbicides in these important weeds of temperate rice. The following herbicides were tested: bensulfuron-methyl, halosulfuron, cinosulfuron, imazamox, and bispyribac-sodium. The smallflower umbrella sedge and ricefield bulrush biotypes studied exhibited different cross-resistance patterns, some of which have not been previously reported. The Italian smallflower umbrella sedge biotype was cross-resistant to bensulfuron-methyl, cinosulfuron, imazamox, and bispyribac-sodium, but was susceptible to halosulfuron. One smallflower umbrella sedge biotype from California was also resistant to bensulfuron-methyl, imazamox, and bispyribac-sodium, but had a lower level of resistance to halosulfuron. In contrast, the second smallflower umbrella sedge biotype from California was strongly resistant to halosulfuron and was also resistant to bensulfuron-methyl and bispyribac-sodium, but moderately resistant to imazamox. The Spanish smallflower biotype was resistant to the sulfonylurea herbicides bensulfuron-methyl and halosulfuron. Different responses were observed in ricefield bulrush. The Italian biotype was resistant to the sulfonylureas only, whereas the biotype from California exhibited broad cross-resistance to all the ALS herbicides tested. Knowledge on cross-resistance is needed to formulate herbicide use and weed management strategies for delaying the evolution of resistance to ALS herbicides in rice systems.

Determining Physiological Maturation of Jointed Goatgrass (Aegilops cylindricaHost) Caryopses

2006 ◽  
Vol 20 (4) ◽  
pp. 921-933 ◽  
Author(s):  
Michael P. Quinn ◽  
Don W. Morishita ◽  
William J. Price
Keyword(s):  
Predictive Model ◽  
Model Validation ◽  
Weed Management ◽  
Management Strategies ◽  
Developmental Rate ◽  
Control Measures ◽  
Jointed Goatgrass ◽  
Early Germination ◽  
Second Year ◽  
Days After Anthesis

Information on jointed goatgrass caryopsis development is currently lacking in published literature. It is hoped that through a better understanding of jointed goatgrass caryopsis ontogeny more effective weed-management strategies will be developed. Greenhouse experiments were initiated in fall 2002 and 2003 and completed the following spring seasons. Jointed goatgrass plants were started from spikelets, vernalized for 8 wk at 4 C, and grown in a greenhouse. Treatments were the number of days after anthesis (DAA) that a spike was allowed to remain on the plant before harvesting and ranged from 2 to 34 DAA, in increments of 1 (2002) or 2 (2003) d. Individual spikes were divided at harvest into three sections: top, middle, and bottom, disarticulated from the rachis, placed into a germinator, and germination recorded each day. Goatgrass spikelets germinated as early as 2 DAA, although spikelets harvested <7 DAA had <3% germination for all spike sections and were extremely variable, especially for the middle and bottom sections. Time to germination was similar for all sections of the spike. Maximum average germination of the top section was 72% compared with 86% for the bottom and middle sections. Our data suggest that factors other than developmental rate (i.e., dormancy) may affect germination in sections of the spike. A second year of the experiment was conducted for validation. Model validation suggested that although trends were similar in both years, variation in germination response might be too great for accurate, predictive model construction. The early germination shown in this research demonstrates that control measures must be implemented earlier than previously prescribed to prevent jointed goatgrass reproduction.

Primary Dormancy and Seedling Emergence of Black Nightshade (Solanum nigrum) and Hairy Nightshade (Solanum physalifolium)

Weed Science ◽  
2009 ◽  
Vol 57 (5) ◽  
pp. 526-532 ◽  
Author(s):  
Alireza Taab ◽  
Lars Andersson
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Seedling Emergence ◽  
Management Strategies ◽  
Soil Disturbance ◽  
Control Measures ◽  
Climatic Extremes ◽  
Primary Dormancy ◽  
Hairy Nightshade ◽  
Black Nightshade

Variation in primary dormancy among populations of black nightshade and hairy nightshade collected on two dates was investigated. In addition, emergence characteristics of both species were studied during 2 yr with several populations and soil disturbance regimes. Results revealed a variation in the level of primary dormancy among populations and collection dates in black nightshade. However, fresh seeds of hairy nightshade showed no or negligible germinability, indicating a deeper level of dormancy. Emergence was higher in black nightshade than in hairy nightshade in both years, but with significant differences among populations. In addition, various categories regarding the soil temperature requirements for seedling emergence were found within seed batches. This enables the species to extend their emergence timing and therefore escape from climatic extremes or weed control operations. This information can be used to improve weed management strategies by timing weed control measures to larger seedling flushes.

Vegetative growth response of black cherry (Prunus serotina) to different mechanical control methods in a biosphere reserve

2012 ◽  
Vol 42 (12) ◽  
pp. 2037-2051 ◽  
Author(s):  
Peter Annighöfer ◽  
Peter Schall ◽  
Heike Kawaletz ◽  
Inga Mölder ◽  
André Terwei ◽  
...  
Keyword(s):  
Tree Species ◽  
Management Strategies ◽  
Species Abundance ◽  
Biosphere Reserve ◽  
Control Measures ◽  
Prunus Serotina ◽  
Black Cherry ◽  
Control Methods ◽  
Mechanical Control ◽  
European Forest

We assessed the effectiveness of different management strategies against the non-native invasive tree species black cherry ( Prunus serotina Ehrh.). The species causes substantial management problems in European forest ecosystems, like the Valle del Ticino Biosphere Reserve in Italy, by suppressing the regeneration of native tree species. This can modify ecological key processes and cause biodiversity loss. Since chemical and biological control has mainly been abandoned in European forest ecosystem management, mechanical control measures are presently the preferred option to proceed against the black cherry but have shown very limited results in the reserve. The aim was to control the success of felling the species and to test other mechanical control methods such as girdling and snapping the trees with regard to their efficiency by quantifying the species’ growth reactions. For this purpose, observational studies were conducted in two forest stands of which one was treated in 1996 and the other more recently in 2009. A subsample of resprouting stumps was treated a second time in 2010 to observe the effect of a direct second cutback. An experimental study was implemented in a third forest stand also in 2010 to compare three different mechanical control methods. The results suggest that felling black cherry is ineffective if the objective is to reduce the species’ abundance because resprouts occur on 100% of the treated trees and biomass increment is not reduced in the long term. Girdling proved to be the most effective treatment across the diameter classes considered.

scholarly journals Selectivity of herbicides applied, in pre-emergence, during the establishment phase of sugarcane

2020 ◽  
Vol 13 (6) ◽  
pp. 16
Author(s):  
R. C. A. Araújo ◽  
A. M. C. Marinho ◽  
R. G. S. Sobrinho ◽  
V. H. C. Sousa ◽  
L. C. Souza ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Strategies ◽  
Residual Effect ◽  
Crop Productivity ◽  
Soil Conditions ◽  
Control Methods ◽  
Initial Development ◽  
History Of ◽  
Absolute Control

Sugarcane is a very important crop in the history of Brazil, since the period of colonization. Among the factors that affect its yield in commercial areas, weeds could be highlighted. Appropriate management strategies are essential to mitigate this interference and increase crop productivity. In this sense, the aim was to evaluate the effect of different control methods on weed management, in the pre-emergence of two varieties, of cane-plant. The experiment was conducted at  Primavera Farm, Itambé (PE), in randomized blocks, in a 2x5 factorial scheme, with 4 replications. The first factor represented two varieties of sugarcane (RB867515 and RB92579) and the second five weed control methods (weed control, absolute control, s-metalochlor + tebuthiuron, sulfentrazone and oxyfluorfen). The number of tillers per linear meter, degree of phytotoxicity and weed control were evaluated. At the end of the research, the RB92579 variety can be used as an alternative for the weed control because it presents rapid sprouting and initial development and more aggressive tillering than RB867515, under Itambé (PE) soil conditions. It is recommended the use of sulfentrazone at the dose of 1.8 L.ha-1.p.c, for better residual effect and "sufficient" control of weeds in the stage of establishment of the culture.

Effect of Financial Control Mechanisms on Performance of Income Generating Units in Selected Public Universities in Kenya

2019 ◽  
Vol 3 (V) ◽  
pp. 286-304
Author(s):  
Shadrack Musunkui Towett ◽  
Isaac Naibei ◽  
Williter Rop
Keyword(s):  
Risk Management ◽  
Internal Control ◽  
Public Universities ◽  
Management Strategies ◽  
Internal Audit ◽  
Simple Random Sampling ◽  
Target Population ◽  
Control Measures ◽  
Financial Control ◽  
Control Mechanisms

In an attempt to bridge the gap between the budgetary allocations and actual expenditures most universities have started income generating units with the aim of boosting their operational expenses. Whereas there is the potential of the use of Income Generating Units (IGUs) to generate additional funds, most universities still experience challenges in full implementation and realization of the revenue goal. This study therefore sought to determine the financial control mechanisms affecting performance of income generating units among selected public universities. The study sought to determine the effect of internal controls, credit policies, financial risk management and internal audit on performance of income generating units in selected universities. Targeted population was all the 290 employees in the IGU departments of selected public universities. The respondents were sampled using simple random sampling so as to enable equal representation of the target population without any biasness. Data collection was done using the questionnaire to ensure sufficient data was collected from the respondents. Descriptive statistics assisted in the determination of respondent’s views and opinions on every variable. Qualitative data was analysed using content analysis into meaningful, precise and comprehensive statements and presented in quotations. Data analysis was done using SPSS version 21 and data presented in form of figures and tables. The study ensured that all ethical considerations were considered by the study. The findings were that most employed Income Generating Units in Public Universities were Collection of rental fees, Evening and executive programs and Trainings of both short and long courses while the least was established to be Sales of memorabilia and books. All the financial control mechanism investigated namely internal audit, internal control measures, risk management strategies and credit policies had large extents of adoption in the selected universities. The results of the regression analysis showed that the financial control mechanisms investigated had a significant positive relationship on performance of the IGUs. Specifically, 47% of the variation of the performance of IGUs was established to be explained by the studied factors. The study concluded that the performance of the IGUs among the selected public universities was largely accounted for by the implemented financial control measures. Therefore effective financial control mechanisms is concluded to lead to better IGU performance whereas shortcomings in the financial control mechanisms is concluded to lead to diminished returns in the IGUs. The study recommended that the management in charge of the IGU department in the public universities to prioritize the formulation, implementation and monitoring of financial control mechanisms in the IGUs. To facilitate effective financial controls, the study recommended that the management especially those in the audit section to conduct regular checks and inspections on the IGUs. Additionally, frequent reforms were recommended to address the shortcomings experienced in integrating financial control measures in IGUs.

IPM—A Problem-based Learning Approach

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 509e-509
Author(s):  
Robert P. Rice
Keyword(s):  
Pest Control ◽  
Test Performance ◽  
Management Strategies ◽  
Ornamental Plants ◽  
Real Life ◽  
Problem Based Learning ◽  
Control Measures ◽  
Learning Approach ◽  
Pest Monitoring ◽  
Use Of Resources

The Cal Poly philosophy of “Learn and Understand by Doing” has been integrated with problem-based learning and the use of the latest technology to produce a class that closely simulates real-life pest control situations. Goals of the class, Disease and Pest Control Systems for Ornamental Plants, are to teach students pest monitoring, control and problem solving techniques, the use of resources including the internet and journals, and the use of the latest pest control equipment and application techniques. Students are shown pest situations and then work in groups to diagnose the problem, investigate management strategies, apply control measures, and monitor results. Weekly class presentations inform the class of the various projects and help to teach the class organization and presentation skills. Student evaluations and test performance have demonstrated that students achieve class objectives substantially better with the problem-based learning approach than with the previous lecture-based approach to the class.

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