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Maritime pine (Pinus pinaster Ait.) is a fast-growing pine species of the western Mediterranean Basin with important ecological (e.g., site restoration), economic (e.g., wood production), and social (e.g., recreation) values. Due to global climate change, the growing incidence of drought and wildfires challenges the distribution and growth of maritime pine. Mechanical site preparation (SP) either alone or integrated with chemical weed control can enhance site conditions for conifer seedlings, specifically by improving the physical and chemical condition of the soil and eliminating weeds. The study was established in the eastern Marmara Region of Turkey and included various SP techniques and cultural treatments (CT) of differing intensity applied in a factorial design before the plantation of one-year-old maritime pine seedlings. The SP treatments included raking by a bulldozer (SPB), raking by a bulldozer and then spraying with 1%-(v:v) glyphosate (SPH), and raking by a bulldozer followed by the broadcasting of the subsoil via bulldozer (SPS), the latter being the standard and the most intensive forest management SP treatment. The CT included various combinations of hoeing and foliar applications of glyphosate after planting. The SPH treatment was the overall best SP treatment in terms of seedling performance and physical and chemical soil properties at one and two YAT. The most intensive treatment (SPS) resulted in significantly reduced seedling growth, survival, and deterioration of physical and chemical soil properties, especially soil organic matter and nutrients. Hoeing in a 1-m radius around seedlings one year after planting (i.e. once during the experiment) (H1) significantly improved seedling survival and vigor compared to the control (H0). No additional gain in seedling survival or growth occurred with more intensive CT combinations. In summary, hoeing at the end of the first summer (H1) following the SPH is recommended for enhanced early seedling performance and soil productivity. [ABSTRACT FROM AUTHOR]

In the field of the Agricultural University of Athens, the effects of tillage on weed suppressive ability, leaf area, seed yield and protein content of velvet bean (Mucuna pruriens) were evaluated under the climatic conditions of Greece. The experiment was carried out in a randomized complete block design with three replicates. The three experimental treatments were: control (untreated), one hoeing for weed seedlings' elimination at 7 days after sowing, and two hoeings for weed seedlings' elimination at 7 and 15 days after sowing. Findings revealed that one hoeing reduced annual weeds' density by 42% as compared to control treatment. Two hoeings resulted in a 47% lower density for annual species as compared to the untreated check. The density of perennial weeds recorded in the plots of one-hoeing treatment was 52% lower than the value recorded in the plots of control treatment. It was also shown that two hoeings can result in a 61% lower density regarding perennial species. Regarding velvet bean's vegetation growth, one hoeing increased velvet bean leaf area per plant by 26% whereas, in the plots of two-hoeings treatment, the value of leaf area per plant was by 22- 36% higher than the corresponding value recorded in untreated control plots. Two hoeings can increase velvet beans seed yield by 44% as well as seeds' protein content by 17%. Further research is needed to optimize the use of velvet bean as a cover crop and seek for agronomic practices that might enhance its competitiveness against both annual and perennial weed species. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the effects of weed density and different weed control treatments on chickpea yield and yield components. The experiment was carried out in split plot design with 3 replications in experimental fields of Kirsehir Ahi Evran University during 2016 and 2017 crop seasons. Total nine treatments (no weed control, permanent weed control, one-time hoeing, two-time hoeing, three-time hoeing, herbicide application after emergence, one-time hoeing with herbicide application, two-time hoeing with herbicide application and three-time hoeing with herbicide application) were compared to know the most effective weed control method. Vaccaria pyramidata Medik., Sinapis arvensis L., Acroptilon repens L. weed species were found to be the most intense in the experimental area. All weed control applications had significant effect on chickpea yield and yield components compared to weedy plots. Three-time hoeing with herbicide application increased the yield by 361.55-478.50% compared to weedy plots. Likewise, three-time hoeing application even increased the yield by 348.50-357.09% compared to weedy plots. The results revealed that threetime hoeing with herbicide and three-time hoeing applications stood out in weed management to obtain a good yield in chickpea cultivation at Kirsehir province. [ABSTRACT FROM AUTHOR]

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The absence of registered herbicides for quinoa cultivation poses a significant challenge in achieving effective weed control through alternative methods. Field experiments, in two growing seasons (2021 and 2022) using different intensities of weed control treatments in quinoa were carried out at the Swojczyce Research and Teaching Station of the Wroclaw University of Environmental and Life Sciences. Three varieties of quinoa: Titicaca, Vikinga, and Zeno were sown at 50 cm inter-row spacing. Weeding treatments with a weeder were performed at BBCH (Biologische Bundesanstalt, Bundessortenamt und CHemische Industrie) phases 13, 17, and 50, with the choice of 1, 2, or 3 treatments. In the variant with 3 weed control treatments, all weeds in the rows were removed at the end of June after the last treatment and evaluation of weed infestation. The varieties responded similarly to the weeding treatments, and the differences in the parameters determined resulted from morphological characteristics. Three inter-row weeding treatments reduced weed count by 70.5% and weed weight by 56.4%. As a result of the increased intensity of weeding treatments, the weed structure changed, and the proportion of common lambsquarters (Chenopodium album L.) increased while that of other dicotyledonous species decreased. Mechanical treatment also had a positive effect on the morphological features of quinoa plants and seed yield. Compared to the control, it increased by 35.8%. The study showed the strong competitiveness of common lambsquarters against quinoa. The biomass of a single quinoa plant and the weight of a single panicle were negatively correlated with the biomass of common lambsquarters. The practical application of inter-row weeding on soils with common lambsquarters in the seed bank may not have the expected economic effect. • Quinoa is a species for which there are no herbicides. • Mechanical weed control intensity was very effective between rows. • Chenopodium album L. was most common weed species. • Quinoa varieties responded similarly to weed competitiveness. • Weed competition influenced on quinoa yield parameters. [ABSTRACT FROM AUTHOR]

Weed hoeing can be successfully performed in wide row crops, such as sugar beet, maize, soybean and wide spaced cereals. However, little experience is available for hoeing in narrow cereal row spaces below 200 mm. Yet, mechanical weed control can pose an alternative to herbicide applications by reducing the herbicide resistant populations present in the field. In this experiment, it was investigated whether hoeing is feasible in cereals with 150 and 125 mm row spacings. The trial was set up at two locations (Ihinger Hof and Kleinhohenheim) in southwest Germany. Three different conventional hoeing sweeps, a goosefoot sweep, a no-till sweep and a down-cut side knife were adjusted to the small row widths, and hoeing was performed once with a tractor and a standard hoeing frame which was guided by a second human operator. The average grain yield, crop and weed biomass, and weed control efficacy of each treatment were recorded. The goosefoot and no-till sweep were tested at driving speeds of 4 and 6 km·h−1. The down-cut side knife was applied at 4 km·h−1. The results indicate that hoeing caused no yield decrease in comparison to a conventional herbicide application or manual weeding. The highest yield with a mechanical treatment was recorded for the no-till sweeps at both trial locations. Hoeing was performed successfully in narrowly spaced cereals of 150 and 125 mm, and the weed control efficacy of the mechanical treatments ranged from 50.9% at Kleinhohenheim to 89.1% at Ihinger Hof. Future experiments are going to focus on more distinct driving speeds ranging from 2 to 10 km·h−1 and performing more than one pass with the hoe. Additionally, combining the mechanical weeding tools with a camera-steered hoeing frame could increase accuracy, allow for higher working speeds and substitute the second human operator guiding the hoe.

While machines called weeding robots are now commercially available and many more designs are being actively researched, I contend that current machines are not truly robotic weeders, rather they are essentially self-guiding vehicles carrying weeding tools. I consider true robotic weeders to be a far more difficult objective. While advances in robotics have been outstanding, the weeding component often appears to be an afterthought. I contend that the weeding is as complex as the robotics. A genuine weeding robot should be able to: (i) monitor the crop, weeds, weather and soil, (ii) decide when the crop should be weeded, (iii) choose the optimal weeder, (iv) take the weeder to the field, (v) adjust the weeder for optimal performance, (vi) continuously monitor the entire weeder for blockages and mechanical breakages and fix them in the field, (vii) continuously monitor and adjust the weeder's performance, (viii) return the weeder to the farmyard and (ix) clean, maintain and store the weeder, that is replace all human intervention. This ten-point list both defines and is a guide to what is required for completely autonomous robotic weeding. Currently, this list is far beyond current technology and it may be decades before it is realisable. The aim of this study therefore was not to disparage the achievements of agricultural roboticists, rather it is to highlight the complexity and demands of mechanical weeding and therefore describe what is really required to create a true robotic weeder. I therefore hope it will guide and expedite research and lead to more rapid success for robotic weeding. [ABSTRACT FROM AUTHOR]

The use of herbicides for weed control in plant production is widely criticized because of their potential aquatic and terrestrial toxicity. However, the environmental risks of mechanical weed control as an alternative control method in row crops have not yet been studied in Europe. Field trials in Southern Lower Saxony were carried out over three years on five sugar beet fields to assess the effect of weeding by hoeing on earthworm abundance, runoff, and soil erosion. Treatments were hoeing (H), herbicide spraying (S) and combined hoeing-spraying (HS), tested in four replicates at each field. The abundance of adult and juvenile earthworms of anecic and endogeic groups was determined in autumn using formalin expulsion 4 months after the final weed control operation. Runoff and soil erosion in mechanically and chemically weeded plots were measured by means of rainfall simulation on 2-m2 subplots after weed control. The experiment was organized in completely randomized block design. The abundance of adult and juvenile earthworms of anecic and endogeic groups was not affected by the weed control treatment. Cumulative runoff and soil loss were significantly reduced by mechanical weed control by a factor of six and eight, respectively, but only if the soil was crusted before weed control. In the absence of a soil crust before weed control there was no difference in runoff and erosion between mechanical and chemical weed control. Measured runoff and soil loss were used to calculate the curve number (CN) and the soil loss ratio (SLR) which are the empirical parameters for the prediction of runoff and soil erosion with the Curve Number SCS method and the Revised Universal Soil Loss Equation, respectively. CN was significantly increased and SLR tended (p =0.08) to be increased if the soil was crusted before weed control. Mechanical weed control reduced CN and SLR in crusted soils but had no effect in non-crusted soils. Therefore, for correct runoff and soil erosion prediction the effect of crusting and mechanical weeding on CN and SLR must be considered. In conclusion, mechanical weeding was revealed to be particularly beneficial for crusted soil by simultaneously reducing toxicological and erosional risks. • Earthworm abundance in autumn was not decreased after mechanical weeding. • Soil erosion was significantly reduced after mechanical weeding only for crusted soil. • Cumulative precipitation after tillage and weeding strategy are improtant predictors of runoff in sugar beet fields [ABSTRACT FROM AUTHOR]

Public awareness and environmental policies have increased interest in applying non-herbicide weed control methods in conventional farming systems. Even though mechanical weed control has been used for centuries in agricultural practice, continuous developments—both in terms of implements and automation technologies—are continuously improving the potential outcomes. Current mechanical weed control methods were evaluated for their weed control efficacy and effects on yield potential against their equivalent herbicide methods. Furthermore, not much is known about the correlation between weed control efficacy (WCE) of different mechanical methods at varying weed density levels. A total of six experiments in winter wheat (2), peas (2), and soybean (2) were carried out in the years 2018, 2019, and 2020 in southwestern Germany. Harrowing and hoeing treatments at different speeds were carried out and compared to the herbicide treatments and untreated control plots. Regarding the average WCE, the combination of harrowing and hoeing was both the strongest (82%) and the most stable (74–100%) mechanical treatment in the different weed density levels. Whereas, in average, hoeing (72%) and harrowing (71%) were on the same WCE level, but harrowing (49–82%) was more stable than hoeing (40–99%). The grain yields in winter wheat varied between 4.1 Mg∙ha−1 (control) and 6.3 Mg∙ha−1 (harrow), in pea between 2.8 Mg∙ha−1 (hoe slow) and 5.7 Mg∙ha−1 (hoe fast) and in soybean between 1.7 Mg∙ha−1 (control) and 4 Mg∙ha−1 (herbicide). However, there were no significant differences in most cases. The results have shown that it is not possible to pinpoint a specific type of treatment as the most appropriate method for this cultivation, across all of the different circumstances. Different field and weather conditions can heavily affect and impact the expected outcome, giving, each time, an advantage for a specific type of treatment. [ABSTRACT FROM AUTHOR]

The need for herbicide usage reduction and the increased interest in mechanical weed control has prompted greater attention to the development of agricultural robots for autonomous weeding in the past years. This also requires the development of suitable mechanical weeding tools. Therefore, we devised a new weeding tool for agricultural robots to perform intrarow mechanical weed control in sugar beets. A conventional finger weeder was modified and equipped with an electric motor. This allowed the rotational movement of the finger weeders independent of the forward travel speed of the tool carrier. The new tool was tested in combination with a bi-spectral camera in a two-year field trial. The camera was used to identify crop plants in the intrarow area. A controller regulated the speed of the motorized finger weeders, realizing two different setups. At the location of a sugar beet plant, the rotational speed was equal to the driving speed of the tractor. Between two sugar beet plants, the rotational speed was either increased by 40% or decreased by 40%. The intrarow weed control efficacy of this new system ranged from 87 to 91% in 2017 and from 91 to 94% in 2018. The sugar beet yields were not adversely affected by the mechanical treatments compared to the conventional herbicide application. The motorized finger weeders present an effective system for selective intrarow mechanical weeding. Certainly, mechanical weeding involves the risk of high weed infestations if the treatments are not applied properly and in a timely manner regardless of whether sensor technology is used or not. However, due to the increasing herbicide resistances and the continuing bans on herbicides, mechanical weeding strategies must be investigated further. The mechanical weeding system of the present study can contribute to the reduction of herbicide use in sugar beets and other wide row crops. [ABSTRACT FROM AUTHOR]

Weed hoeing can be successfully performed in wide row crops, such as sugar beet, maize, soybean and wide spaced cereals. However, little experience is available for hoeing in narrow cereal row spaces below 200 mm. Yet, mechanical weed control can pose an alternative to herbicide applications by reducing the herbicide resistant populations present in the field. In this experiment, it was investigated whether hoeing is feasible in cereals with 150 and 125 mm row spacings. The trial was set up at two locations (Ihinger Hof and Kleinhohenheim) in southwest Germany. Three different conventional hoeing sweeps, a goosefoot sweep, a no-till sweep and a down-cut side knife were adjusted to the small row widths, and hoeing was performed once with a tractor and a standard hoeing frame which was guided by a second human operator. The average grain yield, crop and weed biomass, and weed control efficacy of each treatment were recorded. The goosefoot and no-till sweep were tested at driving speeds of 4 and 6 km·h−1. The down-cut side knife was applied at 4 km·h−1. The results indicate that hoeing caused no yield decrease in comparison to a conventional herbicide application or manual weeding. The highest yield with a mechanical treatment was recorded for the no-till sweeps at both trial locations. Hoeing was performed successfully in narrowly spaced cereals of 150 and 125 mm, and the weed control efficacy of the mechanical treatments ranged from 50.9% at Kleinhohenheim to 89.1% at Ihinger Hof. Future experiments are going to focus on more distinct driving speeds ranging from 2 to 10 km·h−1 and performing more than one pass with the hoe. Additionally, combining the mechanical weeding tools with a camera-steered hoeing frame could increase accuracy, allow for higher working speeds and substitute the second human operator guiding the hoe. [ABSTRACT FROM AUTHOR]