Sometimes You Need a Big Hammer: Evaluating and Appraising Selected Nonherbicidal Weed Control Methods in an Integrated Weed Management System

2019 ◽  
Vol 30 (5) ◽  
pp. 195-200 ◽  
Author(s):  
Daniel Jones ◽  
Daniel Eastwood

Control and management of invasive plants frequently differs from agricultural weed control as plant establishment and development progresses in less intensively managed systems. This is particularly the case for rhizome-forming invasive plants, such as Japanese knotweed (Fallopia japonica var. japonica) as minimum disturbance regimes permit the accumulation of significant below ground reserves that allow recovery from many physical, biological, chemical and integrated control methods. Here, we review the ongoing work of Jones, who established the world's largest and longest running invasive knotweed field trial. Using an integrated weed management (IWM) approach to testing, this research evaluated 19 different control treatments over three years to minimise pesticide use and increase the sustainability of controlling this ecologically and economically damaging species. Through consideration of plant biology, it was found that glyphosate-based herbicide treatments that exploited phenological changes in rhizome source-sink were significantly more effective than all other treatments. These results provide a roadmap to the more effective and efficient control of rhizome-forming invasive plants and emphasise the importance of scale appropriate empirical evidence to inform regulators when considering non-agricultural weed control. Within intensively managed arable agricultural systems, weed control is directed toward immature annual and perennial plants, during a 'critical period' extending for a relatively short time after crop emergence. This is because at this time, resource depletion by weed species may exert a major negative effect upon crop yield. Agronomic weed management may be achieved using a range of weed control methods, including: cultural/preventative (e.g. soil cultivation, disrupting weed establishment), physical (mechanical methods or hand weeding), biological (biocontrol or bioherbicides), chemical (plant protection products; PPPs) and integrated weed management (IWM). True IWM systems combine cultural, physical, biological and/or chemical methods; integrated herbicide management systems use a range of PPPs to mitigate selection of resistant weed populations. In contrast, control of invasive weed species, or invasive alien plants (IAPs) is commonly undertaken in less intensively managed systems, or unmanaged areas such as abandoned agricultural land, riparian areas and brownfield sites. Here, IAPs tend to be large and well-established so that plant persistence and development processes are often unhindered by weed control methods typically applied in agriculture. This is particularly true of rhizome-forming invasive species, such as Japanese knotweed (Fallopia japonica var. japonica) where minimal disturbance regimes permit the long-term development of significant carbohydrate reserves within perennating rhizome organs below the soil surface (>50 cm). Storage reserves permit recovery from repeated intentional disturbance and biological control; while physical size, depth, resilience and strong seasonal changes in source-sink strength of such organs preclude effective chemical control using many herbicides, as insufficient herbicide active ingredient is accumulated within storage tissues. There are strong environmental, ecological and economic cases for the management of IAPs to minimise their negative impacts. However, invasive plant management is hindered by the absence of scale appropriate empirical evidence to support control method selection and plant traits which are effective against control, e.g. rhizome bud bank. Consequently, control programmes may have less than optimal results in terms of economic and environmental sustainability. Terminology is critically important when defining clear programme objectives (i.e. control, management, eradication) and long-term assessment of IAP control and post-treatment habitat recovery is needed to establish best practice. In the case of Japanese knotweed, an approach that works with the seasonal resource translocation between above- and below-ground biomass and adequate herbicide coverage is the key to success. Physical disruption of the plant or increasing use of herbicide application will not give better control and may be less effective and costly. There is increasing public concern (real and perceived) about the widespread use of herbicides, and glyphosate in particular, resulting in increased PPP deregulation and reduced concentration and application rates. Experimental data that define best practice are essential to inform regulators when considering non-agricultural weed control. While the use of PPPs to control perennial IAPs is relatively small, the detrimental environmental, economic and amenity impacts are significant, such that the loss of effective PPPs should be of concern. In the absence of glyphosate, the only effective alternative for Japanese knotweed control would be complete physical excavation and disposal which would be significantly more expensive and arguably more environmentally harmful due to increased associated CO2 emissions and the risk of further spread.


2005 ◽  
Vol 75 (4) ◽  
pp. 79-84 ◽  
Author(s):  
D. Shaner

Some of the first products of biotechnology to reach the marketplace have been herbicide-resistant crops. Industry sees the development of herbicide-resistant varieties as a way to increase the availability of proven herbicides for a broader range of crops. However, the development of herbicide- resistant crops requires special attention to potential environmental questions such as herbicide usage, selection of resistant weed biotypes and spread of resistance from the resistant crop to wild species. Industry is actively addressing these concerns during the process of development. Proper development and use of herbicide-resistant crops in integrated weed management programs will provide farmers with increased flexibility, efficiency, and decreased cost in their weed control practices without increasing the risk of herbicide-resistant weeds. Furthermore, herbicide-resistant crops should prove to be valuable tools in managing herbicide- resistant weeds.


2021 ◽  
Vol 27 (1) ◽  
pp. 51-66
Author(s):  
Haseeb Ahmad

An experiment entitled: Maize yield as affected by methods of tillage and weed control methods was conducted at Agronomy Research Farms, The University of Agriculture Peshawar during summer 2016. The study was conducted in randomized complete block design (RCBD) with split plot arrangement having four replications. Tillage practices 1) Chisel plough + rotavator 2) Mouldboard plough + rotavator 3) Cultivator + rotavator and 4) Rotavator were assigned to main plots. Weed management practices included 1) Control, 2) Hoeing 15 days after sowing 3) Hoeing 15 and 30 days after sowing 4) Hoeing 15, 30 and 45 days after sowing, and 4) Herbicide (nicosulfuron) were kept into the subplots. The results revealed that chisel plough + rotavator has significantly reduced weeds m-2 (122, 101 and 125 weeds m-2), weeds fresh weight (19.73 g m-2, 116.35 g m-2 and 252.56 g m-2) and weeds dry weight (6.83 g m-2, 38.69 g m-2 and 80.61 g m-2) at 30, 45 and 60 days after sowing, respectively. The operation of chisel plough + rotavator has produced tallest plants (221.22 cm) with maximum grain rows ear-1 (16), grain yield (3586 kg ha-1) and shelling percentage (78.14%). Among weed control methods, hoeing 15, 30 and 45 days after sowing revealed maximum plant height (226.41 cm), grain rows ear-1 (16), grain yield (3604 kg ha-1) and shelling percentage (79.11%). All weed control methods have showed significant reduction in weeds m-2, weeds fresh weight and weeds dry weight. Interaction was also found significant for weeds m-2 at 60 DAS and grain yield of maize. Lowest weeds (56 weeds m-2) at 60 DAS and highest grain yield (4569 kg ha-1) was recorded when seedbed was prepared with chisel plough + rotavator with 3 hoeings (hoeing 15, 30 and 45 days after sowing). It is concluded that treatment of chisel plough + rotavator and hoeing 15, 30 and 45 days after sowing has significantly produced maximum grain yield of maize crop.


2007 ◽  
Vol 6 (6) ◽  
pp. 967-971
Author(s):  
Hassan Muhammad Alizade ◽  
Iraj Nosratti ◽  
Saeed Rasoolzade

2004 ◽  
Vol 18 (4) ◽  
pp. 1006-1012 ◽  
Author(s):  
K. Neil Harker ◽  
George W. Clayton ◽  
John T. O'Donovan ◽  
Robert E. Blackshaw ◽  
F. Craig Stevenson

Herbicide-resistant canola dominates the canola market in Canada. A multiyear field experiment was conducted at three locations to investigate the effect of time of weed removal (two-, four-, or six-leaf canola) and herbicide rate (50 or 100% recommended) in three herbicide-resistant canola systems. Weeds were controlled in glufosinate-resistant canola (GLU) with glufosinate, in glyphosate-resistant canola (GLY) with glyphosate, and in imidazolinone-resistant canola (IMI) with a 50:50 mixture of imazamox and imazethapyr. Canola yields were similar among the three canola cultivar–herbicide systems. Yields were not influenced by 50 vs. 100% herbicide rates. Timing of weed removal had the greatest effect on canola yield, with weed removal at the four-leaf stage giving the highest yields in most cases. Percent dockage was often greater for GLU and IMI than for GLY. In comparison with the other treatments, dockage levels doubled for GLU after application at 50% herbicide rates. The consistency of monocot weed control was usually greater for GLY than for GLU or IMI systems. However, weed biomass data revealed no differences in dicot weed control consistency between IMI and GLY systems. Greater dockage and weed biomass variability after weed removal at the six-leaf stage or after low herbicide rates suggests higher weed seed production, which could constrain the adoption of integrated weed management practices in subsequent years.


2004 ◽  
Vol 44 (12) ◽  
pp. 1195 ◽  
Author(s):  
M. Monjardino ◽  
D. J. Pannell ◽  
S. B. Powles

Most cropping farms in Western Australia must deal with the management of herbicide-resistant populations of weeds such as annual ryegrass (Lolium rigidum) and wild radish (Raphanus raphanistrum). Farmers are approaching the problem of herbicide resistance by adopting integrated weed management systems, which allow weed control with a range of different techniques. These systems include non-herbicide methods ranging from delayed seeding and high crop seeding rates to the use of non-cropping phases in the rotation. In this paper, the Multi-species RIM (resistance and integrated management) model was used to investigate the value of including non-cropping phases in the crop rotation. Non-crop options investigated here were haying and green manuring. Despite them providing excellent weed control, it was found that inclusion of these non-cropping phases did not increase returns, except in cases of extreme weed numbers and high levels of herbicide resistance.


Weed Science ◽  
1998 ◽  
Vol 46 (6) ◽  
pp. 698-702 ◽  
Author(s):  
W. Carroll Johnson ◽  
Benjamin G. Mullinix

Field studies were conducted from 1995 to 1997 near Tifton, GA, to determine the benefits of stale seedbed weed control in cucumber. Three stale seedbed management systems—(1) power till stale seedbeds twice (2 ×), (2) glyphosate application immediately after planting, and (3) combination system of stale seedbeds power tilled once 2 wk prior to planting followed by glyphosate application immediately after planting cucumber—were evaluated as main plots. Subplots were weed management systems after planting cucumber: intensive, basic, and cultivation alone. Weed densities were generally greater in 1996 and 1997 than in 1995. Yellow nutsedge was the overall predominant species in 1995 (46 plants m−2), with Florida pusley being the predominant species in 1996 and 1997, at 80 and 124 plants m−2, respectively. Generally, stale seedbeds shallow tilled 2 × had fewer weeds and greater cucumber yields than stale seedbeds treated with glyphosate. Glyphosate did not adequately control emerged Florida pusley on stale seedbeds, resulting in reduced cucumber yield. Clomazone preemergence and bentazon/halosulfuron postemergence were used for broadleaf weed control in the intensive weed management system. These herbicides injured cucumber plants, delayed maturity, and reduced yield. Based on our results, stale seedbeds shallow tilled 2 × can be integrated into cucumber production and provide effective cultural weed control. Furthermore, these systems will replace the need for potentially injurious herbicides.


Agriculture ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 138 ◽  
Author(s):  
Hilary Sandler

Integrated weed management (IWM) has been part of cranberry cultivation since its inception in the early 19th century. Proper site and cultivar selection, good drainage, rapid vine establishment, and hand weeding are as important now for successful weed management as when the industry first started. In 1940, Extension publications listed eight herbicides (e.g., petroleum-based products, inorganic salts and sulfates) for weed control. Currently, 18 herbicides representing 11 different modes of action are registered for use on cranberries. Nonchemical methods, such as hand weeding, sanding, flooding, and proper fertilization, remain integral for managing weed populations; new tactics such as flame cultivation have been added to the toolbox. Priority ratings have been developed to aid in weed management planning. Despite many efforts, biological control of weeds remains elusive on the commercial scale. Evaluation of new herbicides, unmanned aerial systems (UAS), image analysis, and precision agriculture technology; investigation of other management practices for weeds and their natural enemies; utilization of computational decision making and Big Data; and determination of the impact of climate change are research areas whose results will translate into new use recommendations for the weed control of cranberry.


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