Effective Weed Control Research Articles

Using integrated weed management systems to manage herbicide-resistant weeds in the Canadian Prairies

Although herbicides have been a dominant and effective weed control strategy for decades in Western Canada, herbicide resistance and the lack of new modes of action have resulted in weed management challenges. Integrated weed management strategies have been shown to be successful in controlling certain weed species that are problematic in cropping systems. The objective of this study was to investigate integrated weed management strategies that have been successful on individual species to determine their applicability to a multiple weed species that may coexist in a field. In addition, harvest weed seed control was incorporated into these integrated weed management strategies to determine its impact in western Canadian cropping systems. A 5-year rotational study was conducted from 2016 to 2020 at Beaverlodge, Lacombe, and Lethbridge, AB; Scott and Saskatoon, SK; and Carman, MB, that incorporated integrated weed management strategies such as rotational crop diversity (including winter annuals and perennials), increased seeding rates, crop silaging, chaff collection, and with or without in-crop herbicides. This research confirmed success in managing some species of weeds such as wild oat when increased seeding rates, 2 years of early cut silage barley, and competitive winter cereals were incorporated into a cropping system, even when no in-crop herbicides were applied. However, some weed growth morphologies (e.g., twining weeds) or life cycles (e.g., facultative winter annuals) were not managed successfully with this combination of strategies. Chaff collection provided incremental weed control benefits but did not serve as a replacement for herbicidal weed control. Weed densities had an apparent impact on the success of these integrated weed management strategies, suggesting that the sooner they are adopted, the more likely they are to be successful at maintaining or reducing weed densities. This study not only showed the ability to reduce reliance on herbicides with strategies that can be effective in Western Canada but also highlighted the need for further understanding of different weed species and their responses to integrated weed management strategies, as well as the complexity of managing a weed community with integrated weed management.

Evaluation of Sustainable Strategies for Mechanical Under-Row Weed Control in the Vineyard

Mechanical under-row weed control in the vineyard emerges as a sustainable choice compared to chemical control, with tillage-based approaches proving especially efficient. A rollhacke, finger weeder, and blade weeder are valid alternatives to commonly used implements that cause excessive soil disruption and display suboptimal efficiency. The trial aimed to compare different under-row weed control strategies in terms of weed control efficacy and operational performance. Among these, in ST1, a tool-holder equipped with both a rollhacke and finger weeder was used at the first and second intervention; in ST2, a rollhacke was used at the first intervention and blade weeder at the second one; in ST3, firstly the tool-holder equipped with a rollhacke and finger weeder was used, then the blade weeder; in ST4, a rollhacke was used first and then the tool-holder equipped with a rollhacke and finger weeder. Weed height, weed cover, and weed biomass were evaluated before the first and after the second intervention. Total field time, fuel consumption, and CO2 emissions of each strategy were assessed. ST1 proved to be the best compromise in terms of weed control effectiveness and operational performance compared to the other strategies. Indeed, ST1 tendentially achieved a lower weed height (20.42 cm) and weed biomass around vine trunks (105.33 g d.m. m−2) compared to the other strategies. In terms of total field time, fuel consumption and CO2 emissions, ST1 recorded intermediate values equal to 3.85 h ha−1, 15.29 kg ha−1, and 48.72 kg ha−1, respectively. Further studies are needed to evaluate these strategies in different vineyard conditions, considering their effect on weed flora composition. Furthermore, exploring automation technology for real-time implement adjustments based on weed infestation levels could further improve the intervention effectiveness and efficiency.

Effects of allelochemicals from Juniperus phoenicea L. needles on the germination and growth of chosen agricultural crops

In this study, we examined the allelopathic potential of Juniperus phoenicea L. needles on the seed germination and seedling growth of various crops. The investigation focused on the phytotoxic effects of Juniperus phoenicea L. needles, encompassing leachate, aqueous, and organic extracts, on radish, lettuce, barley, and tomato crops. To comprehensively assess their impact, we established pot cultures by incorporating needle powder into the soil at rates of 50 and 100 g/kg, accompanied by irrigation with leachate and aqueous extracts at concentrations corresponding to IC50 (50 % growth inhibition) and the minimum inhibitory concentration (MIC, resulting in 100 % growth inhibition).The volatile components of petroleum ether, chloroform, and acetone extracts were subjected to gas chromatography–mass spectrometry (GC–MS) analysis to elucidate their chemical composition. The germination index underwent significant reduction due to the influence of the needle extract and leachate. Concerning growth, the needle extract exhibited maximum toxicity at a concentration of 40 g/L. Remarkably, the needle leachate exerted a pronounced inhibitory effect on the growth of radish, tomato, and lettuce seedlings, notably at a concentration of 200 g/L.In the context of organic extracts, all three fractions displayed substantial toxicity at a concentration of 30 mg/kg. Incorporating residues into the soil at a rate of 100 g/kg led to a notable decrease in the root and shoot length of the target crops. Soil irrigation with aqueous needle extracts and leachate adversely affected radish, lettuce, and tomato. The biomass of J. phoenicea L. emerges as a potential source of herbicidal substances, offering a promising avenue for integration into agricultural systems to achieve effective and sustainable weed control. However, to solidify these findings within authentic field conditions and to identify specific bioactive compounds for the development of sustainable weed management strategies, further research is imperative.

Efficacy of different herbicides for controlling grass predominant weed flora and achieving higher production in dual purpose linseed under mid hills of Himachal Pradesh

A field experiment was conducted to study the effect of herbicide treatments on the weed flora and the production of the dual-purpose Linseed. The results revealed that grassy weeds viz., Phalaris minor, Lolium temulentum and Avena ludoviciana constituted 43.2, 23.2 and 17.2% of the total weed flora at 90 DAS. Among the broadleaf weeds, Vicia sativa and Spergulla arvensis constituted about 8.4% of total weed flora. As the crop was mainly infested with grassy weeds, effective control of total weeds with the application of clodinafop 60 g/ha (Post.), pendimethalin 1.0 kg/ha (Pre.) and isoproturon 1.25 kg/ha (Post.) as equivalent to hand weeding twice resulted in significantly higher seed, straw, biological, oil and fibre yield of Linseed. As far as the economics is concerned, significantly higher net returns of ₹ 54401 and 3051/ha and net returns per rupee invested (2.01 and 1.90) were obtained by statistically similar treatments of clodinafop 60 g/ha (Post.) and pendimethalin 1.0 kg/ha (Pre.), respectively. Thus, depending upon the situation in dual-purpose Linseed, selecting either of these appropriate chemicals is the better option for controlling grass-predominant weed flora and obtaining higher yields (seed and fiber) with better returns.

Enhancing Sugar Beet (Beta vulgaris L.) Yield and Quality: Evaluating the Efficiency of Chemical and Mechanical Weed Control Strategies

Weeds exert a pronounced influence on the sugar beet yield, leading to the potential for substantial reductions in agricultural productivity. In pursuit of addressing this issue, two experiments were conducted at the Faculty of Agriculture in Giza, Egypt, during the winter seasons of 2020/2021 and 2021/2022 to investigate the efficacy of various pre- and post-herbicides applied differently in active ingredient percentages, forms, and on weed target types, and mechanical weed treatments on weed traits and sugar beet crop performance. (1) In this context, five herbicidal treatments, including pre-emergence (S-Metoachlor) and post-emergence applications of Betanal Max Pro (Desmedipham 4.7% + Ethofumesate 7.5% + Lenacil 2.7% + Phenmedipham 6%), Tegrospecial (Desmedipham 20% + Phenmedipham 20%) for total annual weeds, C Factor (Haloxyfop-R-Methyl 7.5% + Fluazifop-p-putyl 15%), and Clictar (Clethodium 24%) for grassy weeds, were assessed alongside mechanical weeding and a weedy check (control). (2) The evaluations encompassed growth parameters, juice quality, and beet yields to comprehensively assess the treatment effects. (3) Notably, weed control measures, especially regarding three total annual weeds herbicides and the cultivation when using both grassy weed herbicides, consistently produced the highest improvements in sugar beet root’s fresh and dry weights, root dimensions, sucrose content, purity, sugar recovery, as well as the root and recoverable sugar yields, across both seasons. (4) However, it is important to note that the application of Clethodium 24% and Haloxyfop-R-Methyl 7.5% + Fluazifop-p-putyl 15% resulted in elevated levels of sodium, potassium, amino nitrogen, impurities, and sucrose loss to molasses. These findings underscore the substantial influence of herbicide use and mechanical weeding on sugar beet’s growth, juice quality, and yield, with S-Metoachlor, Desmedipham 20% + Phenmedipham 20% and Desmedipham 4.7% + Ethofumesate 7.5% + Lenacil 2.7% + Phenmedipham 6%—showing promise as effective weed control options, albeit with certain associated drawbacks.

Optimizing Pre-emergence Herbicide Oxyfluorfen Dose based on Its Sorption and Desorption for Effective Weed Management under Different Soil Types

Background: Adsorption and subsequent release of pre-emergence herbicide into the soil solution decides the herbicide availability to kill the weeds. Herbicides applied on clay or organic rich soil type, absorb more results in lowering its availability in soil solution become sub lethal to kill the weeds, whereas sandy soil adsorb less and desorb more, sometime it increases the herbicide concentration to toxic level to crop. Effective weed control could be achieved by studying the variability of soil and deciding the dose based on the sorption and desorption properties of the soil. Methods: With this information on the background a laboratory experiment was conducted at the Department of Agronomy, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai, India during 2021 to study the optimum level of oxyflourfen concentration in soil solution required to kill the weeds effectively. The study on sorption and desorption was carried out with pre-emergence herbicide oxyflourfen with five different concentrations in five different soil types. Result: The highest sorption of 98.53 per cent was observed with clayey soils followed by sandy clay loam soils with high organic matter content (96.97 per cent). The lowest sorption (77.96 per cent) was recorded with sandy loam soils. The highest desorption of 57.44 per cent was recorded with sandy loam soil and the lowest desorption percentage (13.18 per cent) was obtained with sandy clay loam soil with higher organic matter. Based on the analytical results of sorption and desorption, oxyflourfen dose was optimized as 0.53 kg ha-1 for sandy clay loam soils with high organic matter, 0.34 kg ha-1 for clay soil, 0.29 kg ha-1 for sandy clay, 0.21 kg ha-1 for sandy clay loam soil and 0.12 kg ha-1 for sandy loam soils. In conclusion, the clay soil required more quantity of oxyflourfen compared to other types of soil for effective management of weeds under irrigated condition.

Performance and Degradation of Nonwoven Mulches Made of Natural Fibres and PLA Polymer-Open Field Study.

The need for sustainable alternatives to conventional plastic mulches in agriculture has led to the development of various types of biodegradable mulches made from natural fibres and biopolymers to reduce environmental pollution and mitigate soil pollution caused by conventional plastic mulch usage. Degradation, impact on soil temperature and humidity, and weed suppression properties of needle-punched nonwoven mulches of different mass per unit area, made of jute, hemp, viscose, and PLA biopolymer, are investigated. Their biodegradation is determined by changes in the mulch properties (mass per unit area, thickness, air permeability, tensile properties, microscopic images, and FTIR analyses) during 300 days of exposure to the environmental conditions in the period from May 2022 to February 2023. The change in mass per unit area, thickness, air permeability, and tensile properties of nonwoven mulches did not show a tendency to degrade during exposure to environmental conditions. The microscopic and FTIR analysis showed the degradation of the fibres from the mulches during the exposure time to a certain extent. The environmental conditions influence the change in the dimensions of the mulches (shrinkage and expansion)-which impact periodically tested mass results per unit area-as well as their thickness and air permeability. The nonwoven mulches provide higher temperatures compared to bare soil, though not as high as those observed beneath traditional agricultural foil. When comparing the humidity in bare soil and soil covered by mulches during the plant growth period (June to October), it was found that soil humidity was higher beneath all mulches. The nonwoven mulches provide superior soil moisture retention compared to conventionally used agrofoil. Almost all nonwoven mulches effectively suppressed weed growth, except hemp mulches. The newly produced mulches have the potential to replace traditional agrofoil, offering improved conditions for plant growth, effective weed control, and faster degradation without causing harm to the environment.

A comparison of seven innovative robotic weeding systems and reference herbicide strategies in sugar beet (Beta vulgaris subsp. vulgaris L.) and rapeseed (Brassica napus L.)

AbstractMore than 40 weeding robots have become commercially available, with most restricted to use in crops or fallow applications. The machines differ in their sensor systems for navigation and weed/crop detection, weeding tools and degree of automation. We tested seven robotic weeding systems in sugar beet and winter oil‐seed rape in 2021 and 2022 at two locations in Southwestern Germany. Weed and crop density and working rate were measured. Robots were evaluated based on weed control efficacy (WCE), crop stand loss (CL), herbicide savings and treatment costs. All robots reduced weed density at least equal to the standard herbicide treatment. Band‐spraying and inter‐row hoeing with RTK‐GPS guidance achieved 75%–83% herbicide savings. When hoeing and band spraying were applied simultaneously in one pass, WCE was much lower (66%) compared to the same treatments in two separate passes with 95% WCE. Hoeing robots Farmdroid‐FD20®, Farming Revolution‐W4® and KULTi‐Select® (+finger weeder) controlled 92%–94% of the weeds. The integration of Amazone spot spraying® into the FD20 inter‐row and intra‐row hoeing system did not further increase WCE. All treatments caused less than 5% CL except for the W4‐robot with 40% CL and the combination of conventional inter‐row hoeing and harrowing (21% CL). KULT‐Vision Control® inter‐row hoeing with the automatic hydraulic side‐shift control resulted in 80% WCE with only 2% CL. Due to the low driving speed of maximum 1 km h−1 of hoeing robots with in‐row elements, treatment costs were high at 555–804 € ha−1 compared to camera‐guided inter‐row hoeing at 221 € ha−1 and broadcast herbicide application at 307–383 € ha−1. Even though the costs of robotic weed management are still high, this study shows that robotic weeding has become a robust, and effective weed control method with great potential to save herbicides in arable and vegetable crops.

Efficacy of Herbicide Mixtures for Transplanted Aman Rice in Silty Clay Loam Soil of Bangladesh

Weed management plays an important role in obtaining target yield. A field experiment was carried out at the Agronomy field of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, from July to December 2019 to get the most effective weed control strategy for transplanted Aman rice. The soil of the study field was silty clay loam in nature. The study consisted of two factors i.e., variety (4: Chinigura, BR11(Mukta), BRRI dhan56, and BRRI hybrid dhan6) and herbicide (4) viz., Bispyribac-sodium WP @ 150 g ha-1, Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1, Pretilachlor 6% + pyrazosulfuron 0.15% WP @ 9.88 kg ha-1, and weedy check as a control. The experiment was laid out in a split-plot design with three replications. Thirteen weed species were found in the experimental plots, mostly broadleaf and sedge. Monochoria vaginalis was the most dominant weed species. The study noticed that the application of mixed herbicides offered better weed control over single herbicide application. Application of Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1 significantly reduced weed density and biomass and was the best way of controlling complex weed flora. The study marked out BR11 (Mukta) as the most potential aman rice variety to produce the highest yields at applying Acetochlor 14% + Bensulfuron methyl 4% WP @ 750 g ha-1. This treatment gave the highest gross return (Tk. 1,46,010), net return (Tk. 88,699), and benefit-cost ratio (2.55). Therefore, the study suggests the application of mixed herbicides and BR11 (Mukta) to get the optimum yield of transplanted Aman rice and maximum economic benefit.
 Bangladesh Agron. J. 2023, 26(1): 56-74

Evaluation of Sowing Methods and Herbicide Mixtures for Weed Management and Productivity in Sesame (Sesamum indicum L.)

Sesame is an oil seed crop with great economic value. However, the production of this crop has been limited by weed competition, which prompted a field experiment during the 2021 cropping season in two locations: Teaching and Research Farm, Kwara State University, Malete, and National Centre for Agricultural Mechanization (NCAM), Idofian, Ilorin, Kwara, Nigeria. The aim was to determine the treatment combinations of sowing methods and herbicide mixtures for the effective management of weeds and for increasing sesame productivity in the southern Guinea savanna of Nigeria. The experiment consisted of twenty treatments comprising two sowing methods (dibbling and drilling) and ten weed control methods. Results showed that all the weed control methods reduced weed dry matter (67.15–186.20 and 42.00–92.45 g/m2) than the weedy check (291.55 and 155.55 g/m2) at Malete and NCAM, respectively. They also reduced the weed density (48.40–68.45 and 34.00–50.00/m2) compared to the weedy check (103.60 and 73.15 g/m2) at Malete and NCAM, respectively, from 6 to 12 weeks after planting (WAP). Dibbling (85.15 and 48.81 m2) proved superior to the drilling method (172.42 and 51.58/m2) for the management of weeds from 6–12 WAP and for promoting higher crop yield (dibbling: 78.90 and 422.70 kg/ha; drilling: 37.50 and 326.80 kg/ha) in Malete and NCAM, respectively. The treatment combinations with the highest gross margin were hoeing twice at 3 and 6 WAP × dibbling ($ -191.15 and $ 318.57), pendimethalin (P) + diuron (D) at 0.5 + 0.5 kg a.i./ha ($ -199.88 and $ 182.43), 2.0 + 1.5 × dibbling ($ -273.59 and $ 156.65) and butachlor (B) + diuron (D) at 1.5 + 1.0 kg a.i./ha × drilling ($ -269.59 and $ 177.38) at Malete and NCAM, respectively. Therefore, it is recommended that the dibbling sowing method at a spacing of 30 cm × 30 cm and thinned to 3 plants/stand integrated with herbicide mixtures of pendimethalin at 0.5 + 0.5 kg a.i./ha is recommended as an alternative to hoe weeding for effective weed control, higher yield of sesame, and economic returns.

Steam application with paraquat to control goat weed (Scoparia dulcis) in citrus orchards

Reducing herbicide use in horticultural crop production can ameliorate adverse environmental effects but may also impact weed control effectiveness, especially as it pertains to difficult-to-control weeds. This challenge can be addressed by integrating a non-chemical strategy such as steam application with herbicide application. In this study, steam, as a non-chemical approach, was combined with post-emergence herbicide (paraquat) application for goatweed (Scoparia dulcis) management in citrus orchards. Two field trials based on randomized complete block design were conducted in citrus orchards in Immokalee, FL, in 2018 and 2021. Steam was applied to goatweed at a flow rate of 53 L ha−1 for 5–6 s. Twenty-four hours after steam application, low and high paraquat rates (0.3366 and 1.010 kg ai ha−1) were applied. In addition, the same rates of paraquat were applied without steam for comparison. Untreated checks (UTC) of no herbicide or steam applications were also included in the experiment as a control. Based on visual injury ratings, a combination of steam + low dosage of paraquat was as effective as the high dosage of paraquat alone and steam + high dosage of paraquat at 1, 8, and 16 days after treatment application (DAT) in 2018 trial and 1, 8, 16 and 22 DAT in 2021 trial.However, based on one site-year of biomass data, the percentage of dead weed biomass out of total biomass was statistically similar among all the treatments. Results from this study demonstrate that combining a low rate of paraquat applied in tandem with the steam application has the potential to provide effective goatweed control in citrus orchards.

Do intercropping and mineral nitrogen fertilizer affect weed community structures in low-input maize-based cropping systems?

Weeds are a major threat to crop growth in sub-Saharan Africa (SSA), particularly in low-input cropping systems. We investigated the effect of different cropping systems and nitrogen fertilizer on weed infestation during the 2017/18 and 2018/19 cropping seasons in Goromonzi district, Zimbabwe. The objectives of this study were to (1) determine if and how weed composition and structure are affected by intercropping maize with either an improved or landrace cowpea variety compared to sole crops of maize and of improved or landrace cowpea; (2) if and how weed composition and structure are affected by nitrogen fertilization; and (3) how the subsequent changes in weed infestation affect grain yield. Weed parameters were measured at different dates during the cropping cycle, and grain yield was measured at harvest. Significant differences were observed for the density of the 21 weed species collected in two seasons; seven of these weed species had a relative density exceeding 5%. Significantly more weeds were recorded in sole maize compared to sole cowpea. Intercropping significantly reduced the density of C. benghalensis. In sole crops, application of mineral nitrogen fertilizer significantly affected weed density, diversity, richness, and groundcover. Maize grain yield was independent of weed biomass and density, in both sole crops and intercrops. However, increase in weed biomass significantly reduced cowpea yield. Our results suggest that growing sole cowpea reduces weed infestation, therefore, cowpea should be considered as one of the options for effective weed control in subsistence farming communities, where access to herbicides is lacking.

A low-cost practical approach to markedly improving rice cultivation using kiko volcanic rock derived pellets to enhance the plants' alternative cellular energy (ACE) pathway via KELEA activation of groundwater.

Abstract Plants can utilize an energy source that is different from the energies provided by photosynthesis and food catabolism. Water can act as a carrier of this life force energy, which is referred to in this article as KELEA, an abbreviation for Kinetic Energy Limiting Electrostatic Attraction. KELEA activated water provides cellular energy and facilitates various biological processes through the alternative cellular energy (ACE) pathway. Pellets composed of previously pulverized and heated volcanic rock material can increase the level of KELEA in water. Effective pellets are commercially available under the name Kiko. This article extends earlier observations regarding the markedly improved quality and quantity of rice that can be harvested from farmlands treated with Kiko pellets. The study was performed using the Jasmine ST25 strain of rice cultivated in the Mekong District of Vietnam. It compared rice growing in two composite areas of farmland, each area comprising 100 hectares. Except for the possible influence of beneficial microbes, the use of thirty (30) Kiko pellets per hectare before the rice seeding reportedly achieved major benefits throughout the rice growing process. The benefits included more effective weed control, more efficient germination, and more abundant tiller, panicle, and rice grains. These benefits resulted in a remarkable 29% increase in total harvested rice and nearly 40% increase in the amount of milled rice. Specifically, the Kiko versus control harvested values were 6.2 versus 4.8 tons per hectare and the milled values were 4.3 versus 3.1 tons per hectare, respectively. KELEA activation of water is achievable using various methods, but few are currently as straightforward as the described use of relatively small numbers of Kiko pellets. Utilizing KELEA activated water should become standard practice in the production of the world's food crops, including rice.

The Dynamics of Sugar Maize (Zea mays saccharata Sturt.) Infestation of Field Pansy (Viola arvensis).

Field pansy infestation can lead to a decrease in the species diversity of plant communities and to the disappearance of other species. Field pansy infestation is fairly common in many crops, including maize. Understanding the ecology and management strategies for field pansy in maize is essential for effective weed control. This research into sugar maize was conducted from 1992 to 2019 in the Research and Education Center Gorzyń, Złotniki branch, which belongs to the Poznań University of Life Sciences. The assessment of weed infestation was carried out in experiments that focused on chemical weed control in maize. The experiments were established as single-factor randomized block designs with four field replications. The aim of the study was to evaluate dynamic changes in the status and the degree of field pansy infestation in sugar maize that was cultivated after various other crops in the Wielkopolska region, with a focus on weather conditions. The results indicated that the probability of field pansy individuals occurring among the total number of weeds was highest when maize was cultivated after wheat, but the probability of such infestation did not significantly differ when maize was sown in a crop rotation after winter triticale.

Comparison of water-saving potential of fallow and crop change with high water-use winter-wheat – summer-maize rotation

A land fallow system (LFS) designed to adjust the winter-wheat summer-maize cropping system to fallow summer-maize was introduced in Hebei Province to alleviate groundwater depletion in the region. However, some of the water saved was lost through evaporation from bare soil and transpiration by weeds. So far, no measurement has been done in the region to address this non-productive water loss, thereby limiting the water-saving potential of the introduced LFS. Furthermore, the reduction in crop production under the summer-maize – fallow system threatens food security. The objective of this study was to determine which practice is effective to keep soil water during fallow and the exact water-saving potential of different cropping system in the region. Firstly, field experiments were conducted under various soil surface management systems — including plastic mulching (PM), straw mulching (SM), shallow tillage (ST) and weed control (WC). The effects of saving water, controlling weeds and managing nutrients were analyzed under the various surface soil management methods. The results showed that compared with the control (no soil surface management, CK), 177, 64.7, 71.0 and 25.0 mm of water was saved respectively under PM, SM, WC and ST surface soil management methods in 2019–2020. The effect of weed control decreased in the order of PM > WC > SM > ST. While PM significantly increased soil nutrient in all the treatments, the others showed slight but insignificant increases. Secondly, the precise water-use of each of the cropping systems was determined using large lysimeters. The analysis showed that compared with the wheat-maize system, 60–100 mm of water was saved under alternating wheat-soybean, wheat-millet, mung bean – fresh edible maize, spring sweet potato cropping systems. The results were key for technical guide in developing future cultivation adjustment policies.

Evaluation of two‐pass herbicide programs for broad‐spectrum weed control in conventional tillage non‐transgenic corn production in Wisconsin atrazine prohibition areas

AbstractAchieving effective weed control is crucial for Wisconsin conventional corn growers farming in atrazine prohibition areas. Upon request from our extension clientele, a field study was conducted at Arlington and Brooklyn, WI, in 2021 and 2022 (four site‐years). The study aimed to evaluate the weed control efficacy of comprehensive two‐pass (PRE followed by POST) herbicide program treatments containing products with a wide range of active ingredients and sites of action from various manufacturers without atrazine and glyphosate, in conventional tillage non‐transgenic corn production. Nine and eight out of the 11 two‐pass herbicide programs investigated provided >90% giant foxtail (Setaria faberi Herrm), common ragweed (Ambrosia artemisiifolia L.), velvetleaf (Abutilon theophrasti Medik) and waterhemp [Amaranthus tuberculatus (Moq.) J.D. Sauer] control in 2021, respectively. However, only three treatments provided >90% waterhemp control and the greatest giant foxtail control in 2022 was 79%. Greater end‐of‐season broadleaf and grass weed control was observed in 2021 compared to 2022 due to lower weed pressure and timely early‐season rainfall in 2021. The two‐pass programs, acetochlor/mesotrione fb dicamba/tembotrione (94%–100%) and acetochlor/flumetsulan/clopyralid fb nicosulfuron + dicamba/diflufenzopyr (85%–100%), provided the most consistent broadleaf control across all site‐years. These results demonstrate that a well‐designed and timely deployed two‐pass herbicide program can provide effective control of common broadleaf and grass weeds in conventional corn production assuming moderate weed pressure and timely rainfall for soil residual herbicide activation, otherwise effective weed control, particularly of grass weeds, in the absence of atrazine and glyphosate can be challenging. These results are also translatable to support weed management decisions for glyphosate‐resistant corn hybrids in non‐atrazine prohibition areas.

Telomere-to-telomere genome assembly of an allotetraploid pernicious weed, Echinochloa phyllopogon

Abstract Echinochloa phyllopogon is an allotetraploid pernicious weed species found in rice fields worldwide that often exhibit resistance to multiple herbicides. An accurate genome sequence is essential to comprehensively understand the genetic basis underlying the traits of this species. Here, the telomere-to-telomere genome sequence of E. phyllopogon was presented. Eighteen chromosome sequences spanning 1.0 Gb were constructed using the PacBio highly fidelity long technology. Of the 18 chromosomes, 12 sequences were entirely assembled into telomere-to-telomere and gap-free contigs, whereas the remaining six sequences were constructed at the chromosomal level with only eight gaps. The sequences were assigned to the A and B genome with total lengths of 453 and 520 Mb, respectively. Repetitive sequences occupied 42.93% of the A genome and 48.47% of the B genome, although 32,337, and 30,889 high-confidence genes were predicted in the A and B genomes, respectively. This suggested that genome extensions and gene disruptions caused by repeated sequence accumulation often occur in the B genome before polyploidization to establish a tetraploid genome. The highly accurate and comprehensive genome sequence could be a milestone in understanding the molecular mechanisms of the pernicious traits and in developing effective weed control strategies to avoid yield loss in rice production.

USE OF HERVICIDES FOR WEED CONTROL AND THEIR EFFECTS ON YIELD PERFORMANCE OF WHEAT (Triticum aestivum L)

This experiment was carried out in the research farm of the Regional Wheat Research Institute, Shampur, Rajshahi during the period from November last week 2019 to April first week 2020 in order to the find out “USE OF HERVICIDES FOR WEED CONTROL AND THEIR EFFECTS ON YIELD PERFORMANCE OF WHEAT (Triticum aestivum L) .’’ Wheat sown both conventional and strip method. In this research yield and yield contributing characters were found and maximum wheat production observed by under strip tillage method (4.48 t/ha). In randomized complete block design (RCBD) with three replications in both tillage systems with some herbicides were tested for weed control treatment. The maximum number of effective and total tiller per meter square, 1000 grain weight, were observed in T4(Affinity, BD.) herbicides for weed control treatment. As a result, maximum grain yield was obtained in T4 treatment. The 2nd maximum yield was recorded in T6 (Axial + Affinity, India) herbicides for weed control treatment. The lowest grain and other yield contributing characters were found in T9 (Weedy check) condition. The effect of interaction between different method of cultivation and weed control treatment were insignificant for all yield and yield contributing characters except plant height, grain yield and straw yield.

Cross and multiple herbicide resistance across Ukraine

Goal. Identify resistance to herbicides in weed species on the crops of leading agricultural companies in the regions of Ukraine and identify ways to counteract the emergence of resistant weed biotypes.
 Methods. The research of herbicide effectiveness was carried out in production and vegetation experiments. Control plants were collected on non-arable land. Statistical analysis was performed using StatPlus software from AnalystSoft Inc.
 Results. Field and greenhouse studies in 2014—2023 identified herbicide resistance in highly damaging biotypes of monocotyledonous and dicotyledonous weed species in Ukraine. In 2022—2023, herbicide-resistant ragweed (Ambrosia artemisiifolia L.) affected sunflower crops, the main crop that ensures the profitability of crop production in the country. Imidazolinone resistance in Ambrosia was identified in 2015. In 2023, multiply resistance to herbicides — acetolactate synthase inhibitors and protoporphyrinogen oxidase inhibitors (ALS+PРO) — was identified in A. artemisiifolia in large areas of sunflower in central and southern Ukraine. In previous years, resistant to the action of herbicides — acetolactate synthase inhibitors of the imidazolinone class ‒ imazapyr and imazamox biotypes of monocot Echinochloa crus-galli var. crus-galli (L.) P. Beauv., and dicot Amaranthus retroflexus L., and Chenopodium album L. have been identified. Cross-resistance to herbicides: monocot to sulfonylurea (nicosulfuron), and triazole pyrimidines (penoxsulam); dicots to sulfonylurea foramsulfuron, iodosulfuron-methyl-sodium, thifensulfuron-methyl, tribenuron-methyl; to sulfonylaminocarbonyl triazolinone derivative — thiencarbazone-methyl; to triazole pyrimidine derivatives — florasulam, and flumetsulam were established. The multiple resistance of Echinochloa crus-galli, Amaranthus retroflexus, and Chenopodium album to herbicides of the classes of glycine derivatives — glyphosate, monocot to graminicide pinoxaden, and dicot species to phenoxy carboxylic derivatives — 2.4-D, benzoic acid — dicamba; triketones — topramezone; diphenyl ethers — aclonifen have not been established. It was shown that herbicide compositions under the influence of the ammonium pool can increase the level of controlling resistant weed biotypes effectiveness. In 2018—2021, in rice crop rotations in the South of Kherson region, the emergence and spread of a cereal multiply resistant (ALS + ACC) species, Eragrostis spp. was detected.
 Conclusions. The identification of highly harmful resistant Ambrosia artemisiifolia, Echinochloa crus-galli, Amaranthus retroflexus, Chenopodium album, and Eragrostis spp. in the South and Central part of the «grain belt» of Ukraine shows the limited effectiveness of weed control exclusively with herbicides with one mechanism of action and requires a significant revision of the principles of crop rotation formation and methods of weed control in the state to maintain high levels of profitability and productivity of agrophytocenoses. Solving these issues is urgent in order to preserve Ukraine’s potential as one of the guarantors of world food security.

THE EFFICACY OF ISOPROPYL AMINE GLYPHOSATE 165 SL HERBICIDE EFFECT ON WEED CONTROL OF COCONUT CULTIVATION

Coconut plants are an important commodity for Indonesian people. In the cultivation process, coconut plants need a suitable environment for growth and production. One of the problems in cultivation is weeds. Weeds have a negative impact on cultivated plants, therefore appropriate control measures are needed. So far, the most effective weed control is chemical methods using herbicides. One of the herbicides that can be used is the herbicide with isopropyl amine glyphosate 165 SL. The aim of the experiment was to determine the efficacy of the herbicide isopropyl amine glyphosate 165 SL for controlling weeds in coconut cultivation was conducted from February to June 2022 at Pariaman City, West Sumatra Province. The experimental units were laid out according to a Randomized Block Design with 7 treatments and 3 groups as replications. The treatment was herbicide isopropyl amine glyphosate 165 SL at doses of 3.50 l ha-1, 5.25 l ha-1, 7.00 l ha-1, 8.75 l ha-1, 10.00 l ha-1, manual weeding and control (without weeding). The results of the research show that (1) The herbicide isopropyl amine glyphosate 165 SL can generally control weeds in coconut cultivation up to 12 weeks after application because the weed biomass in the treatment plot is relatively the same as manual weeding and is lighter than the control; (2) Herbicide isopropyl amine glyphosate 165 SL with a dose range of 3.50 l/ha – 10.50 l ha-1 up to 6 weeks after application does not show symptoms of phytotoxicity in coconut plants.