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Mechanical weed control is a major element of weed suppression in organic farming systems. In addition to the direct effect on weed growth, mechanical weeding, such as harrowing or hoeing, is known to induce side effects on several soil- and crop-related properties. In this study, we investigated the impact of mechanical weeding on soil mineral nitrogen (SMN), soil moisture, and crop yield in an organic crop rotation of grass-clover (Lolium multiflorumLam., Trifolium pratense L.), silage maize (Zea mays L.) and winter barley (Hordeum vulgare L.). The experiment was conducted in two consecutive years (2021, 2022), where each crop was grown in each year on a Plaggic Anthrosol with sandy loam in North-West Germany. Two weed control treatments (mechanical: harrowing, hoeing; chemical: herbicide application) were implemented in a randomized block design with four replications. Greater net nitrogen (N) mineralization in maize compared to winter barley were attributed to the incorporation of grass-clover residues before sowing of maize and greater mineralization potential during the maize growing season. Higher weed growth in maize after mechanical weeding resulted in a reduction of up to 47% in SMN content in the topsoil. In barley, no differences in weed suppression were observed between the treatments and only small effects on SMN were determined after mechanical weeding. The soil water content in the mechanically weeded plots was significantly higher at several events in both years and for both crops, which was attributed to increased water infiltration by disrupting the soil crust. Neither crop yield nor N uptake in harvest products was affected by the different treatments. [ABSTRACT FROM AUTHOR]

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This study proceeded in the spring of 2022 to assess the efficiency of Metribuzin herbicide alone and combined with some agricultural methods, such as mulching and hoeing, to control potato weeds. The effect of Metribuzin at a rate of 400 g ha-1 with mulching reduced the total weed density to 19.0 plants m-2, similar to Metribuzin at a rate of 800 g ha-1 (16.0 plants m-2 ). The efficiency of Metribuzin herbicide at 400 g ha-1 combined with one or two hoeings reduced the number of weed densities by 19.3 and 10.6 plants m-2 for one hoeing and two hoeings, respectively. The effect positively manifested in plant heights, the number of leaves, the foliage dry weight, and its reflection on the potato yield weight. [ABSTRACT FROM AUTHOR]

Weeds cause serious yield losses in sunflower production. The most common methods for weed control are herbicide application and mechanical hoeing. The objective of this study was to determine the effects of five traditional herbicides containing different active ingredients compared with mechanical hoeing for weed control on seed yield components, seed oil content, and fatty acid composition in sunflower. Field experiments were conducted in the sunflower growing seasons of 2014 and 2015 on farmer fields in Karamusul village of Lüleburgaz, Kırklareli, located in the Northwest of Turkey (40°24' N, 27021 E and elevation 46 m). Pre-plant herbicide Bonoflan WG with benfluralin, pre-emergence herbicide Stomp®Extra with pendimethalin, and postemergence herbicides Challenge600 with aclonifen and Targa Super with quizalofop-p-ethyl active were applied on non-Clearfield sunflower hybrids (P64LL05--Linoleic and P64H34--High oleic) while post-emergence herbicide Intervix®Pro with imazamox was applied on Clearfield hybrids (LG5542CL-Linoleic and Colombi--High oleic). In the results, the year effects were statistically significant on plant height, head diameter, number of days from planting to 50% flowering, and percentage of stearic acid of Clearfield cultivars while it was significant on plant height, head diameter, stem diameter, 1000 seed weight, number of days from planting to 50% flowering, seed yield, seed oil content, percentage of oleic and linoleic acids of non-Clearfield cultivars. The effect of genotype was significant for all seed yield and oil components except seed weight and seed yield for both groups' cultivars. Intervix®Pro caused significant decreases in plant height, stem diameter, and percentage of stearic acid. Stomp®Extra decreased the number of days from planting to 50% flowering. Challenge 600 had a negative effect on the seed oil content of P64H34 in 2015. There was no significant difference between herbicide applications and mechanical hoeing for seed yields except for increasing seed yield of P64H34 by Bonaflan WG in 2015. For all herbicide applications, residue in seeds was not exceeded international acceptable limits. According to the results, herbicides especially post-emergence applications under stress conditions can adversely affect agronomic yield and seed oil components in sunflower. [ABSTRACT FROM AUTHOR]

Geranium (Pelargonium graveolens L’Herit ex Ait.) plants infected with root rot and wilt diseases were collected from different locations of Behira, Ismailia and Minia Governorates, Egypt. Fusarium, Macrophomina, Rhizoctonia and Pythium were isolated from the infected plants. The results showed that F. oxysporum recorded the highest isolated rate, followed by R. solani, F. solani, M. phaseolina and Pythium sp. The effect of various concentrations of marjoram and peppermint essential oils on the mycelial growth of the isolated fungi was tested in vitro. Marjoram and peppermint oils completely inhibited the growth of F. oxysporum, F. solani, R. solani and Pythium sp. at the concentration of 5 ml/l. A Field experiment was conducted at the Experimental Farm of Agricultural Research Station, Malawy, Minia Governorate, Egypt, during two successive seasons of 2020 and 2021 to study the effect of different weed control methods (un-weeded control, clover cover yield, hand hoeing and black plastic mulch) on weeds biomass. The results indicated that all weed control treatments significantly decreased the weight of grassy broad-leaf weeds and total weeds compared to the un-weeded control. Moreover, all weed control treatments and plants treated with the essential oils of marjoram and peppermint as well as the biocides (Bacillus subtilis and Trichoderma harzianum) significantly decreased the wilt disease incidence and improved the vegetative growth, yield and volatile oil of geranium plants. The results indicated that plastic mulch was the most effective in reducing wilt incidence as well as increasing all growth characteristics and productivity of volatile oil, while the highest disease incidence and the lowest growth and yield were recorded under un-weeded treatment. The application of the marjoram essential oil or biocide B. subtilis resulted in the lowest incidence of wilt disease and the highest increase in the growth, herb yield, essential oil yield and main components of essential oil. The highest growth characters and volatile oil were recorded with either black plastic mulch and marjoram essential oil or with B. subtilis treatment.

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]

Swallow-wort (Cynanchum acutum L.) is a perennial and invasive weed that infested many sugarcane fields in Khuzestan. Field experiment was conducted to find out an efficient method for C. acutum control in sugarcane during 2018 and 2019. The experiment was split-split plots in a randomized complete block design with three replications. Main plots were pre-emergence application of metribuzin, metazachlor + qinmerac, pendimethalin, indaziflam and acetochlor; Sub plots were one time hand hoeing (four weeks after pre-emergence application), two-times hand hoeing (four and eight weeks after pre-emergence application), and without hand hoeing and sub-sub plots were post emergence application of 2,4-D+MCPA, mixture of 2,4-D+MCPA and metribuzin, and bromoxynil + MCPA herbicides. Results showed that individual application of Pendimethalin, and indaziflam herbicides, two-times if hand hoeing, and then post emergence application of 2,4-D+MCPA and metribuzin as a had the highest efficiency with an average of 96% in reducing mass dry weight. The application of mentioned treatments increased cane yield 104.7 and 102.9 t/ha respectively compared to the control (without weeding, with 110 t. ha-1 ). However, the experimental treatments did not show a significant effect on quality traits of sugarcane. [ABSTRACT FROM AUTHOR]

IntroductionLegumes are the most important source of vegetable protein supply. Seed bean contains 25-22 percent protein, and it has a high nutritional value for human which is a major source of protein supply in most modern societies. Today protein deficiency is one of the acute nutritional problems in the diet of millions of people in developing countries. Bean ranks third after pea and lentil in Iran as one of the developing countries with dry and semi-arid climate. Moreover, as to the weeds management of the cropping systems, weeds are controlled by hand as an earliest means, and by airplanes, chemical pesticides, hormones, and viruses as the most complete tools. Various studies show that weed control treatments especially hand weeding treatments caused higher yield than control treatment, indicating the importance and priority of hoeing in the cultivation of beans. Mulch as a new phenomenon in agriculture has caused a fundamental change in the use of chemical pesticides, controlling weeds in fields, preventing soil erosion, and increasing water penetration in soil layers. Also, the use of plant mulch can compensate soil nutrients and increase the organic nitrogen content of the soil. The advantages of using plants mulch could be increasing soil nitrogen for the main plant, protecting soil erosion, increasing soil quality, reducing evaporation, and increasing water penetration in the soil, improving water use efficiency, maintaining good soil temperature and suppressing weeds. Considering the growing need for weed control in bean fields through non-chemical and mulch applications as an ecological alternative for sustainable agriculture, an experiment was conducted to investigate the effect of tea waste mulch and weed control on morphophysiological and biochemical characteristics of bean. Materials and MethodsThis study was conducted at the Research Farm of Tarbiat Modares University, with a factorial experiment using a RCBD with three replications. Five time of weed control including no weed control, and weed control every 1, 2, 4 and 6 weeks and three rates of tea waste mulch at 0, 5 and 10 ton.ha-1 were used. Common bed preparation techniques such as plowing, disc and leveling was done in a land area of 1000 m-2. The dimensions of each plot were 4 m by 3 m. The planting was carried out on March 20, with a density of 25 plants m-2, with a spacing of 50 cm between the planting rows and eight centimeters on the planting row. The first irrigation was carried out immediately after planting using T-tape. The next irrigation intervals were every 5 days. Results and DiscussionThe results showed that the combined effects of weed control and tea waste mulch on all measured traits were significant. Also, the two-way interaction of these factors was significant for soluble carbohydrate, starch, number of pods per plant of bean and dry weight of weed. The highest yield and yield components of bean were observed in weed control once per week and 10 tons tea waste mulch per hectare. The highest photosynthesis rate and water-soluble carbohydrate content was observed in the same treatment. Weed control reduced the competition of weeds with bean and could provide more resources to the crop. Thus, the application of tea waste mulch affects the absorption of nutrients by the roots. Other studies reported that dandruff mulch, such as mulch, was more effective in control of weeds than light cleared mulches due to the lack of light on the surface of the soil and produces good grain yield. The researchers reported that the highest grain yield was obtained from mulch clichés treatment, which were categorized by black and white plasterboard treatments in a statistical group. ConclusionThe results of this study suggest that weed control and application of 10 tons tea waste mulch per hectare could improve photosynthesis rate, reduce protein content and increase starch and water-soluble carbohydrate contents of bean seed. Weed control once per week after bean emergence and application of five and 10 ton ha-1 mulch reduced weed dry weight by 45.48% and 74.12%, respectively. Finally, application of 10 tons tea waste mulch per hectare and weed control every 2 weeks is recommended for bean fields. Overall, it appears that application of tea waste mulch and weed control at the beginning of emergence was superior for seed production comparing to the late weed control and without mulching.

The fruit fly is one of the most damaging pest of fruits and is mainly managed by integrated pest management. In current study efficacy of seven treatments viz., (Hoeing, Hoeing+ sanitation, Hoeing+ pheromone (methyl eugenol) traps, Spray of Diptrex 80 WP, Hoeing + sanitation+ spray of insecticide (spinosad), Hoeing + sanitation + Diptrex spray, Hoeing + bait application) were analyzed in citrus orchards. Experiment was conducted in three citrus producing districts of Punjab i.e., Sargodha, Toba Tek Singh and Nankana Sahib. Data of % fruit infestation, larval population and market value of fruits was collected at regular intervals. The experimental results indicated that the combined application of hoeing, sanitation, and the spray of spinosad indicated minimum fruit infestation (6.15%) and maximum reduction in fruit infestation is (76.63%) with a cost-benefit ratio (1: 8.43) and after applying the hoeing highest fruit infestation (17.82%) and lowest reduction in fruit infestation (32.29%) with the lowest CBR (1:3.8) were recorded. The maximum reduction in larva population was recorded in the block where the spray of spinosad was applied along with hoeing and sanitation (2.84 larvae/fruit) while integrated application of hoeing, sanitation, and diptrex was showed (3.43 larva/fruit) followed by application of hoeing and pheromone traps (3.63 larvae/fruit) and spray of diptrex alone demonstrated (4.76 larvae/fruit), respectively. In conclusion, integrated application of hoeing, sanitation, and spinosad spray proved better application for suppression of fruit flies larva and reduction of fruit infestation. [ABSTRACT FROM AUTHOR]

The present study was conducted to assess the effect of different herbicides on nutrient uptake, and quality of Kinnow mandarin. Ten year old low-seeded Kinnow plants of uniform size were selected and recommended doses of Glyphosate, Paraquat and Metribuzin herbicides were sprayed under plants canopy three times (during March, July, and November) in a fruiting cycle to eradicate the weeds. The results showed significantly higher N, P, and K contents in the control treatment (2.98% N, 0.395% P, 0.239% K) while these contents were decreased in the treatments of glyphosate (1.68% N, 0.087% P, 0.2% K), paraquat (2.84% N, 0.268% P, 0.249% K) and metribuzin (2.70% N, 0.353% P, 0.205% K). Similarly, morphological parameters such as fruit diameter (6.84cm), fruit weight (156.30 g), number of seeds per fruit (5.06), seed weight (0.47g), peel weight (40.43g), peel thickness (2.13 cm) and average juice weight percentage (53.84%) were substantially higher in the control treatment as compared to weedicide treatments. However, number of fruits per plant (67.78) and average yield per plant (9.48kg) was higher in the metribuzin treatment while rag weight (31.81g) was higher in fruits of glyphosate treatment compared to other treatments. Total sugars (23.98%) and non-reducing sugars (20.76%) were also higher in the control treatment as compared to all weedicide treated plants. However, total soluble solid (10.58°Brix) and titrable acidity (1.02%) were significantly higher in the metribuzin treatment compared to control and glyphosate treatments and non significantly at par compared to paraquat treatment. The paraquat treatment showed maximum vitamin C (42.93 mg 100g-1) and reducing sugars (5.78%) among all treatments while TSS (9.38°Brix, TA (0.94%), Vitamin C (40.23 mg/100g), non-reducing sugars (19.32%) and total sugars (4.09%) had minimum values in the glyphosate treatment. [ABSTRACT FROM AUTHOR]

Sugar beet field trials were conducted at two sites in Southern Lower Saxony to compare mechanical (hoeing), chemical (herbicide spraying) and combined mechanical-chemical weed control operations in their weed control efficacy, and in their effect on mulch coverage and soil erosion by water. Three treatments were tested in four replications at both sites. To measure runoff and soil erosion, rainfall simulations were carried out for mechanical and chemical treatments after completion of the last weed control operation. The cumulative soil loss was twice higher in mechanical than in chemical treatment in Sieboldshausen (p-value=0.03) but was eight times lower in mechanical than in chemical treatment in Obernjesa (p-value=0.004). The cumulative runoff was not significantly different between treatments in Sieboldshausen but was again significantly lower for hoeing than for spraying in Obernjesa. Also the effect on weed control efficacy by second weed control operation (2-4- leaf-stage) was site-specific, with no effect in Sieboldshausen and significantly reduced efficacy of mechanical weed control in Obernjesa. Mulch coverage loss due to the second weed control operation was significantly higher for mechanical than for chemical treatment at both sites.

Copyright of Misr Journal of Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mustafa Kemal University Journal of Agricultural Sciences / Mustafa Kemal Üniversitesi Tarım Bilimleri Dergisi is the property of Mustafa Kemal University, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cultural practices are key tool for ecofriendly management of destructive pests in fruits and vegetables. Clipping, hoeing, mulching, crop rotation, intercropping and synchronization of sowing time are some most important cultural practices to control Leucinodes orbonalis in brinjal crop. The current study was planned to evaluate four different cultural practices against brinjal shoot and fruit borer in brinjal crop during two consecutive years 2018 and 2019 at two locations university research farm (URF) Koont and a farmer's filed Rawat, Rawalpindi including polythene mulching, hoeing, clipping and mulching + clipping as treatments. The results revealed that mulching + clipping reduced about 61 % and 60 % shoot infestation over control at URF Koont and Rawat respectively. Fruit infestation was decreased 67 % and 61 % in the same treatment with increase of 133% and 226% increase of marketable fruit yield over control at URF Koont and Rawat respectively. Maximum cost benefit ratio was also higher in clipping + mulching as compared with other three treatment. Clipping, hoeing and polythene mulching were significantly effective over control but statistically at par with each other. It is concluded that ecological pest management techniques specially adoption of cultural practices may perform better to mitigate the climate changes, market demands and reduction of reliance on chemical options to control Leucinodes orbonalis. [ABSTRACT FROM AUTHOR]

Copyright of Listy Cukrovarnicke a Reparske is the property of VUC Praha a.s. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Weed management is an important and expensive step in groundnut production. Field experiments were conducted in the early and late wet seasons of 2017 to evaluate the effectiveness and profitability of weed management using hoe weeding, herbicides or their combination in groundnut production. Butachlor and propaben at 2.0 kg a.i (active ingredient) ha-1 each followed by (fb) supplementary hoe-weeding (shw) at 6 weeks after sowing (WAS) significantly reduced weed cover and biomass with subsequent increase in groundnut pod yield similar to hoe-weeding treatments and better than either herbicide applied alone. The highest groundnut pod yield (1485.7 kg ha-1) and revenue ($1639.2) in the early season was obtained with three hoe weeding passes. However, in the late season, the highest groundnut pod yield (1146.3 kg ha-1) was obtained with propaben plus hoe-weeding and the highest revenue ($1264.8) obtained with butachlor plus hoe-weeding. Although three hoe-weedings gave the highest revenue in the early season, the gross margin and cost-benefit ratio obtained with hoe weeding treatments was lower than those of herbicides fb shw. This study showed that integrated weed management with butachlor or propaben and fb shw will improve weed control, productivity and profitability of groundnut production. Multiple hoe weeding, however, did not guarantee the highest profit but rather increased the cost of production.

Abstract Background Mulching and manual or mechanical hoeing are the backbone of weed control strategies in organic agriculture. So, two field experiments were established in the village of Kafer El-Khawazim, Talkha district, Dakahlia Governorate, Egypt, during the winter seasons of 2017 and 2018. The experiments were conducted to evaluate the efficiency of the safe weed control methods of mulching and manual hoeing in comparison with metribuzine herbicide on potato plants and associated weeds. Results The results indicated that the treatment of black plastic mulch was the superior treatment in controlling broadleaved, grassy, and total weeds as compared to other treatments under study. Metribuzin herbicide came in the second rank in controlling broadleaved weeds. Concerning to grassy and total weeds, banana leaf and cheeseweed straw mulches follow the black plastic mulch ideal treatment. The results also revealed that the use of black plastic mulch and banana leaf mulch followed by cheeseweed straw mulch led to the highest significant increase in growth characteristics and tuber yield of potato plants. This in turn correlated with a significant increase in tuber contents of phosphorus, potassium, and carbohydrate percentage than unweeded control treatment. Conclusion Black plastic mulch followed by banana leaf mulch and cheeseweed straw mulch were the ideal safe treatments in controlling total weeds. This in turn reflected on potato plants by scoring the maximum values of yield characters as compared to unweeded check.

An experiment to study the performance of weeds in maize crop against different tillage and weed control methods was conducted at Agronomy Research Farm, The University of Agriculture Peshawar during summer 2016. Field experiment was conducted in randomized complete block design (RCBD) with split plot arrangement having four replications. Tillage practices i.e. chisel plough + rotavator, mouldboard plough + rotavator, cultivator + rotavator and rotavator were assigned to main plots. Weeds management practices include control, hoeing 15 days after sowing, hoeing 15 and 30 days after sowing, hoeing 15, 30 and 45 days after sowing, and herbicide (Nicosulfuron) were kept in subplots. The results revealed that chisel plough + rotavator 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 produced tallest plants (221.22 cm) with maximum grain rows ear-1 (16) and shelling percentage (78.14%). Among weed control methods, hoeing 15, 30 and 45 days after sowing showed maximum plant height (226.41 cm), grain rows ear-1 (16), and shelling percentage (79.11%). All weed control methods showed significant reduction in weeds m-2, weeds fresh [ABSTRACT FROM AUTHOR]

This study was conducted to determine the effects of humic acid and iron applications on seed yield, some plant characteristics and oil ratio of Remzibey-05 safflower cultivar under Harran Plain conditions in the 2011-2012 and 2012-2013 growing seasons. The experiment was carried out in randomized complete block split plots design with three replications. The main plots were humic acid (HA) applications (0, 60 g ha-1, 120 g ha-1, 180 g ha-1 ), and the sub-plots were iron (Fe) applications (0, 12.5 kg ha-1, 25 kg ha-1 and 37.5 kg ha-1 ). Humic acid was sprayed onto the leaves and iron was applied to the soil when the plants were leading the stage of 4-5 leaves. The highest seed yield, number of heads per plant and dry petal yield per plant were obtained from 120 g ha-1 humic acid and 12.5 kg ha-1 Fe applications. The highest number of seeds per head was obtained from 180 g ha-1 HA and 12.5 kg ha-1 Fe applications while biomass yield was from 60 g ha-1 HA and 25 kg ha-1 Fe applications. In conclusion; 120 g ha-1 humic acid and 12.5 kg ha-1 Fe should be applied to increase seed yield, number of heads per plant and dry petal yield per plant in safflower agriculture under semi-arid climate conditions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Protection & Pathology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Agriculturae Slovenica is the property of Biotechnical Faculty of the University of Ljubljana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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]

The Farm to Fork strategy of the European Union aims to reduce pesticide use. In weed control, chemical measures are to be replaced mainly by mechanical ones. However, a comprehensive evaluation of mechanical methods with respect to ecological and economic parameters is not yet available. The aim of the study was to quantify relevant ecological and economic parameters of mechanical, mechanical-chemical and chemical weed control in sugar beet as a model crop. An overall consideration of the multidimensional risks for different conventional and new methods revealed that currently no method can be appraised as fully environmentally friendly. Toxicological risk assessment using the model SYNOPS-GIS indicated that broadcast spraying of conventional herbicides is associated with low toxicological risks in most soil-climate-regions and years. Broadcast spraying with herbicides such as CONVISO ONE, while beneficial for energy use, climatic effects, and toxicity to soil organisms, has the highest acute aquatic toxicity. Conventional mechanical methods, while toxicologically safe and, according to field trials, without negative effects on soil biota, soil erosion, or sugar yield, are associated with 100–150% higher greenhouse gas emissions compared to conventional herbicide application. Overall, hoeing with a solar powered robot combined with herbicide spot spraying has the greatest advantages. This technique requires relatively low resource and energy consumption, produces about 5% lower greenhouse gas emissions and has by 87% lower toxicological risk than conventional herbicide spraying. Among pure mechanical techniques, the combination of a solar-driven hoe robot with hand-hoeing appears to be most economic and environmentally sustainable. • Hoeing did not impair yield, soil erosion or number of insects, spiders and earthworms. • No weed control method proves to be completely environmentally friendly. • Conventional hoeing causes 150% higher greenhouse gas emissions as broadcast spraying. • The new herbicide CONVISO ONE, while beneficial in many ways, causes the highest aquatic toxicity over other methods. • FarmDroid hoe robot combined with spot-spraying is a low-toxic, a climate-friendly and an inexpensive technique. [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.

Ground cover management and farmyard manure (FYM) management have important roles in organic lettuce production. However, there is not enough information about their combined effects. In order to assess the effects of individual and combined ground cover and FYM management on soil mineral N (NH4-N and NO3-N) dynamics, lettuce yield and economics in organic farming, a two-year field experiment was conducted on a certified organic farm in Kisač (Vojvodina, Serbia). The experiment had a two-factorial split-plot completely randomized block design. FYM was applied on the half of the experimental field as a whole-plot factor, while ground cover management included the following four treatments: (I) control, without ground cover management (Ø); (II) hoeing (H); (III) agrotextile cover; (IV) straw mulch (SM), which were applied on split plots. The applied SM and AT increased soil moisture by 12.83 and 3.73%, respectively, compared to the control treatment. FYM increased soil mineral N concentration, the lettuce fresh matter (FM) yield and nitrate concentration in lettuce. However, nitrate concentration in lettuce in all treatments was below the limit required by the European Commission (EC) (2001). The highest lettuce yield was obtained by AT (39 122 kg), followed by SM (33 925 kg), and it was higher with FYM application by 16.85%. Hoeing did not positively affect the yield, probably due to its negative effect on soil moisture. Additional profit was higher with FYM, showing the following decreasing order: AT>H>SM>Ø. However, value/cost ratio (VCR) was in the order Ø>H>SM>AT on FYM fertilized plots. FYM application led to higher lettuce yield and higher profit and VCR. In case a farm does not have FYM, SM is the best alternative due to its positive effect on the yield and low investment costs.

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.

Two field experiments were conducted to assess the response of growth, yield and quality of potato crop as well as weed control efficacy (WCE) to different colours (blue, white and black) of plastic mulches, biodegradable (plastic and rice straw) mulches, infrared transmitting (IRT) plastic mulch and natural herbicides (acetic acid 20% (AA), citric acid (CA) 10% and AA 10% + CA 5%) in comparison with hoeing, metribuzin herbicide and unweeded check. At 90 days after planting, black and biodegradable plastic mulches recorded WCE significantly higher than hoeing treatment with values of 98.1% and 93.8%, respectively, compared with 83.1% for hoeing. High WCE was recorded by AA 20% (90.7%), rice straw (90.4%), white (89.6%), IRT (88.1%) and blue (83.7%) plastic mulches and AA 10% + CA 5% (80.5%) which were similar to hoeing treatment. The lowest WCE (70.2%) was obtained by CA 10% treatment. The highest plant shoot fresh weight was recorded in biodegradable and black plastic treatments. Weed infestation in the unweeded plots reduced marketable yield of potato by 57.8%. All plastic and rice straw treatments produced total and marketable yields similar to hoeing treatment. The increase of marketable yield under synthetic and biodegradable mulches ranged from 118.6 to 155.1%. Application of AA 20% and the mixture of AA 10% + CA 5% achieved tuber yields similar to metribuzin herbicide. Biodegradable plastic recorded the largest tuber volume and the lowest physiological disorder yield. The highest starch content was recorded in black plastic and rice straw mulch treatments. It was concluded that mulches and natural herbicides may provide alternative safe weed management methods to hoeing and/or synthetic herbicides in potato crop, especially for new reclaimed areas and organic farms. [ABSTRACT FROM AUTHOR]

Copyright of Listy Cukrovarnicke a Reparske is the property of VUC Praha a.s. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study we investigated the possibility of chemical and mechanical weed control strategies in soybean. Soybean field experiments were carried out in 2013 and 2014 in Southern Germany. Five treatments including common herbicide mixtures and four mechanical weed control treatments, implementing a harrow and a hoe, were tested at different locations. In the herbicide experiments two treatments were applied by PRE emergence herbicides (metribuzin, clomazone, dimethenamid and metribuzin, flufenacet, clomazone) and another two treatments were sprayed with a combination of PRE + POST emergence herbicides (metribuzin, flufenacet, thifensulfuron and pendimethalin, thifensulfuron, bentazone, cycloxydim). Furthermore, a POST herbicide treatment was implemented (thifensulfuron, bentazone, thifensulfuron and fluazifop-P-butyl). In the mechanical weed control experiments, treatments were: three times hoeing, PRE emergence harrowing plus three times hoeing, hoeing and harrowing in rotation or three times harrowing. In both experiments an untreated control was included. A 90% weed control efficacy and 23% yield increase was observed in the POST herbicide treatment. PRE + POST treatments resulted in 92% to 99% weed control efficiency and 15% yield increase compared to the untreated control. In the mechanical weed control experiments the combination of PRE emergence harrowing and POST emergence hoeing resulted in 82% weed control efficiency and 34% higher yield compared to the untreated control. Less weed control efficiency (72%) was observed in the harrow treatment, leading to 20% higher yield compared to the control. The suitability of both strategies for implementation in “Integrated Weed Management” has been investigated.

Rural communities depend upon cotton as cash crop for their livelihood. Agro-based industries are depending upon its yield. Our per acre cotton yield is still far behind than the developed countries. Integrated pest management project was launched in Punjab and run by agriculture extension department. Farmer Field Schools were formed at each village level. Present study was designed to evaluate the role of integrated pest management for cotton production technologies by the registered growers of Hasilpur, Punjab. In order to collect this information an interview schedule was prepared and respondents (150 growers of farmer field school) were interviewed personally by the author. The findings revealed 98.7%, 100% and 98% cotton growers were aware of hoeing, leaf curl virus and biological control of insects-pests. Before integrated pest management all the farmers used pesticides haphazardly while 1.3% used after it. 90.7%, 86.7% and 97.3% farmers were aware of economic threshold level of harmful insects, use of pesticides at economic threshold level and clean cotton picking respectively. 94.7% growers adopted thinning of plants, 91.3% knew pest scouting, 87.3% used pesticides after pest scouting while 74% farmers used pesticides both at morning and evening. It was concluded that integrated pest management project enhanced the skills of farmers and resulted in higher yields of quality cotton through reduction of pesticides sprays. [ABSTRACT FROM AUTHOR]

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]

The objectives of this study were to evaluate baby corn yield, green corn yield, and grain yield in corn cultivar BM 3061, with weed control achieved via a combination of hoeing and intercropping with gliricidia, and determine how sample size influences weed growth evaluation accuracy. A randomized block design with ten replicates was used. The cultivar was submitted to the following treatments: A = hoeings at 20 and 40 days after corn sowing (DACS), B = hoeing at 20 DACS + gliricidia sowing after hoeing, C = gliricidia sowing together with corn sowing + hoeing at 40 DACS, D = gliricidia sowing together with corn sowing, and E = no hoeing. Gliricidia was sown at a density of 30 viable seeds m-2. After harvesting the mature ears, the area of each plot was divided into eight sampling units measuring 1.2 m² each to evaluate weed growth (above-ground dry biomass). Treatment A provided the highest baby corn, green corn, and grain yields. Treatment B did not differ from treatment A with respect to the yield values for the three products, and was equivalent to treatment C for green corn yield, but was superior to C with regard to baby corn weight and grain yield. Treatments D and E provided similar yields and were inferior to the other treatments. Therefore, treatment B is a promising one. The relation between coefficient of experimental variation (CV) and sample size (S) to evaluate growth of the above-ground part of the weeds was given by the equation CV = 37.57 S-0.15, i.e., CV decreased as S increased. The optimal sample size indicated by this equation was 4.3 m².

Copyright of Julius-Kühn-Archiv is the property of Julius Kuehn Institut and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The intelligent control system is a software-hardware system that achieves a differentiation of crop plants from the weeds and after that it destroys the weed. It is based on two intelligent cameras. Each camera surveys two rows of culture and digitally transmits the commands obtained after processing the images, to a logical programmable controller (PLC). This paper presents general aspects and a comparison between two smart cameras; the first one is black-and-white and the second is a colour camera. Recognition and processing of images algorithm depends on colour, shape or position. If the first uses shape to recognize and make the difference between weed and plant, the second uses the difference of colour pixels to make that difference. The paper also includes the stages of algorithm realization and implementation for images processing and recognition. The experiment was performed on lettuce at INMA Bucharest. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water and labour scarcity pushes researchers to explore alternate sowing methods for rice like aerobic direct seeding but weed infestation is the major hindrance to adapt this production system. In our study, mechanical, chemical and cultural approaches were employed as weed control measures. Weed dynamics and yield parameters were recorded and economic analysis was performed. All weed control measures significantly reduced the weed density and weed dry weight as compared to control and improved harvest index. Maximum control in total weed density and total weed dry weight was achieved by hoeing followed by chemical control. The order of treatment groups in decreasing total density, total weed dry matter production and increment in harvest index was as cultural, chemical and mechanical. However, substantially highest net returns (PKR 44,049/) and highest benefit cost ratio (BCR) (1.53) were obtained by post emergence application of Penuxsulam at the rate of 15 g a.i ha-1 followed by hoeing. Inter-culture, mulching technique and Sesbania drummondi intercropping scored 1.19, 1.13 and 1.21 BCR, respectively. Thus, hoeing with hoe (25 and 45 days after sowing) and post emergence application of Penoxsulamat the rate of 15 g a.i ha-1 were most effective, profitable and economical weed control options. [ABSTRACT FROM AUTHOR]

Eggplant shoot and fruit borer (ESFB), Leucinodes orbonalis Guenee, a destructive pest of eggplant (Solanum melongena L.), adversely affects quality and yield of eggplant fruit throughout the world. Currently, its management is mainly relied on insecticides which are inimical to humans, livestock and environment. To get rid of the pernicious consequences of chemicals, use of alternative non-chemical approaches has been emphasized. Ergo, in the present study non-chemical methods viz. hoeing, clipping of damaged fruits and shoots and weeding at weekly intervals and a biocontrol agent Trichogramma chilonis individually and in combination were assessed for the management of ESFB. All the treatments though varied in their efficacies, caused significant reductions in infestation of ESFB and increased yield as compared to control. Combination of practices gave better results as compared to individual treatments with few exceptions. In general, the combined treatment (T. chilonis + hoeing + clipping) was found to be the most effective in reducing pest infestations and increasing yield followed by another combined treatment where hoeing, clipping and weeding were applied conjointly. Application of T. chilonis singly was the least effective treatment; however, incorporation of T. chilonis with other practices gave good results. Similarly, integration of hoeing with clipping of infested shoots and fruits at weekly intervals also proved satisfactory in reducing pest infestation and enhancing yield. It is concluded that integration of non-chemical approaches will help reduce infestation of ESFB significantly and will make a major contribution to both climate-change mitigation and sustainable crop production systems. [ABSTRACT FROM AUTHOR]

There is interest in the identification of the best seeding density for new corn hybrids and on reduced use of herbicides for weed control. The objective of this study was to evaluate the effects of seeding density (30, 50, 70, and 90 thousand plants ha-1) and weed control on green ear yield and grain yield in corn cultivar AG 1051. A completely randomized block design was adopted with split-plots (seeding densities assigned to plots) and ten replicates. Weed control was achieved by means of two hoeings and by planting corn intercropped with gliricidia (between corn rows, in pits spaced 0.3 m apart). A "no weeding"treatment was included as well. Increased seeding density increased the total number and weight of marketable green ears and decreased the biomass of both weeds and gliricidia. In non-weeded, intercropped and hoed plots, the maximum grain yield values achieved as seeding density increased were 7,881, 7,021, and 9,213 kg ha-1, respectively, obtained with populations of 67 thousand, 74 thousand, and 67 thousand plants per hectare, respectively. Intercropping did not control weeds (26 species) and provided weed growth, green ear yield, and grain yield (at the lowest densities) similar to those obtained without hoeing, except for total number of green ears, in which no influence of weed control was observed. At densities of 70 thousand and 90 thousand plants per hectare, grain yield with two hoeings was not different from yield values obtained without weeding or in the treatment intercropped with gliricidia, respectively, indicating that increased corn seeding density as well as gliricidiamay help to control weeds.Existe interesse na identificação da densidade de semeadura ideal para os novos híbridos de milho e na redução do uso de herbicidas no controle de plantas daninhas. O objetivo deste trabalho foi avaliar os efeitos da densidade de semeadura (30, 50, 70 e 90 mil plantas ha-1) e do controle de plantas daninhas sobre os rendimentos de espigas verdes e de grãos da cultivar de milho AG 1051. Utilizou-se o delineamento de blocos completos casualizados com parcelas subdivididas (densidades de semeadura atribuídas às parcelas) e dez repetições. O controle de plantas daninhas foi obtido por duas capinas e pela consorciação do milho com gliricídia (entre as fileiras do milho em covas espaçadas por 0,3 m). Um tratamento "sem capinas"foi incluído como controle. O aumento da densidade de semeadura aumentou o número total de espigas e o peso de espigas verdes comercializáveis e diminuiu a biomassa das plantas daninhas e da gliricídia. Nas parcelas não-capinadas, consorciadas e capinadas foram obtidos rendimentos máximos de 7.881 kg ha-1, 7021 kg ha-1 e 9.231 kg ha-1, respectivamente, com as populações de 67, 74 e 67 mil plantas ha-1, respectivamente. A consorciação não controlou as plantas daninhas (26 espécies) e propiciou crescimento das plantas daninhas, rendimento de espigas verdes e rendimento de grãos (nas menores densidades) similares aos obtidos com a ausência de capinas, exceto para o número total de espigas verdes, no qual não houve influência do controle de plantas daninhas. Nas densidades de 70 e 90 mil plantas ha-1, os rendimentos de grãos obtidos com duas capinas não diferiram dos rendimentos obtidos com a ausência de capinas e com a consorciação, respectivamente, indicando que o aumento da densidade de semeadura, bem como a consorciação com a gliricídia podem auxiliar a controlar as plantas daninhas.

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.

O manejo inadequado das plantas daninhas é uma das principais causas da baixa produtividade da cultura da mandioca no Brasil. Objetivou-se com este trabalho identificar as espécies de plantas daninhas infestantes da cultura da mandioca e o grau de interferência que estas exercem sobre o cultivo, em função do período de convivência com a cultura. Dois experimentos foram realizados em áreas adjacentes, no município de Viçosa-MG, utilizando-se o cultivar Cacauzinha, do grupo das mandiocas mansas. O delineamento experimental adotado foi em blocos casualizados, com sete tratamentos e quatro repetições. Os tratamentos do primeiro experimento foram compostos por períodos iniciais de convivência da cultura com as plantas daninhas: 25, 50, 75, 100 e 125 dias após o plantio (DAP); no segundo experimento, as plantas de mandioca, inicialmente, permaneceram livres das plantas daninhas pelos mesmos períodos. Em ambos os experimentos adotou-se o espaçamento de 1,0 x 0,5 m, sendo a área útil da parcela constituída pelas duas linhas centrais, deixando-se 1,0 m em cada extremidade como bordaduras frontais, totalizando 8,0 m². As plantas daninhas foram avaliadas aos 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325 e 350 DAP. As características produtividade de raízes, peso da parte aérea, índice de colheita, teor de amido e matéria seca das raízes foram avaliadas aos 12 meses após o plantio. As espécies de plantas daninhas que predominaram na área experimental foram: Bidens pilosa, Raphanus raphanistrum, Cyperus rotundus e Commelina benghalensis, com a primeira delas predominando em quase todas as épocas de coletas. Os períodos de convivência com as plantas daninhas não interferiram nos índices de colheita, teor de amido e matéria seca das raízes. Todavia, considerando a produtividade de raízes, o final do período anterior à interferência foi próximo dos 25 dias, e o período crítico de prevenção da interferência situou-se entre 25 e 75 DAP. Cultivos realizados após 75 DAP não afetaram as características da cultura da mandioca avaliadas.Inadequate handling of weeds is one of the main causes of cassava low yield in Brazil. The objective of this work was to identify the weed species interfering in cassava crop and the degree of this interference, in function of then coexistence period. Two experiments were carried out in adjacent areas in Viçosa-MG, Brazil, using the "cacauzinha" cultivar of the cassava group. A randomized block design was adopted, with seven treatments and four replications. The treatments in the first experiment were composed by the initial crop periods and weed coexistence 25, 50, 75, 100 and 125 days after planting (DAP). In the second experiment, the cassava plants initially remained weed-free for the same periods. For both experiments, 1.0 x 0.5 m spacing was adopted, being the useful portion area constituted by the two central lines, with 1.0 m being left in each extremity as front borders, totaling 8.0 m².. The weeds were analyzed at 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325 and 350 DAP. The characteristics root yield, aerial part weight, crop index, starch content and root dry matter were evaluated at twelve months after planting. The prevailing weed species in the experimental area were: Bidens pilosa, Raphanus raphanistrum, Cyperus rotundus and Commelina benghalensis, with Bidens pilosa prevailing in almost all collection times. The coexistence periods with the weeds did not interfere in the crop indexes, starch content and root dry matter. However, taking into account root yield, the end of the period before interference was close to 25 days and the interference prevention critical period was between 25 and 75 DAP. Crops sown after 75 DAP did not affect the analyzed cassava crop characteristics.