scholarly journals Changes in species composition of weeds and their number in potato under the influence of different of weed control method

2013 ◽  
Vol 55 (2) ◽  
pp. 209-220
Author(s):  
Katarzyna Zarzecka

In a strict field experiment we have studied the influence of different weed control method on the species composition and the number on weeds occurring in a field of four potato cultivars. The application of herbicides decreased the number of weeds, as compared with the number obtained for mechanical control by 1,9-5,1 times at the beginning ofthe vegetation and by 1,5-3,7 times prior to tubers harvest. The herbicides considerably reduced the composition of weed species, moreover.

2012 ◽  
Vol 58 (1) ◽  
pp. 291-302
Author(s):  
Krystyna Zarzecka ◽  
Marek Gugała

The results presented in this paper were obtained in the field experminent carried out in the years 1999-2001 on a soil a very good rye complex. In this experiment definited number of weeds and their floristic species composition. The application of mixtures herbicides decreased of number of weeds as compared with the number obtained for mechanical control of 397-500% at the beginning of the vegetation and of 180-220% prior to tubers harvest. The herbicides reduced the composition of weed species, moreover.


Author(s):  
Melih Yilar Omer Sozen ◽  
Ufuk Karadavut

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 three-time hoeing with herbicide and three-time hoeing applications stood out in weed management to obtain a good yield in chickpea cultivation at Kirsehir province.


2012 ◽  
Vol 48 (4) ◽  
pp. 587-596 ◽  
Author(s):  
ANDRÉ ANDRES ◽  
GERMANI CONCENÇO ◽  
GIOVANI THEISEN ◽  
LEANDRO GALON ◽  
FRANCO TESIO

SUMMARYThe weedy variety ofOryza sativaoccurs in several rice cultivation areas reducing both grain yield and quality. Prevention and crop rotation are considered the basic means to reduce its presence. Weed control in sorghum is generally attained with atrazine. In this study, the efficacy of both chemical and mechanical methods for control, under different soil tillage conditions, of weedy rice and barnyardgrass during sorghum cultivation was evaluated with the aim to reduce the application rate of atrazine. In the case of chemical control, the atrazine rate (1000, 1500, 2000, 2500 and 3000 ga.i.ha−1) and application timing (pre- and post-emergence) were assessed. With the mechanical control method, the number of interventions (inter-row hoeing with sorghum at 3, 4–5 and 6–8 leaves) to avoid weed competition was determined. The effect of the tillage system on weed population was investigated comparing conventional (ploughing), minimum-tillage (disc harrowing) and sod seeding (no-tillage) in combination with pre- and post-emergence herbicide treatments. The results showed that efficient control of weedy rice and barnyardgrass was achieved in lowlands with sorghum in rotation with rice. Both chemical and mechanical methods of weed control in sorghum gave a level of efficiency higher than 60%. The application of atrazine was more efficient in pre-emergence application, rather than in post-emergence treatments, in all soil tillage systems tested. On both weed species, the most suitable application rate was the pre-emergence treatment with 1500 ga.i.ha−1, and the adoption of higher rates did not significantly increase the herbicidal efficacy. The adoption of two or three mechanical interventions resulted in sorghum yield higher than the chemical post-emergence application, and similar to the application of atrazine in pre-emergence. Higher yield results were in accordance to greater weed control, being obtained in the conventional tillage system.


2021 ◽  
Vol 58 (3) ◽  
pp. 375-383
Author(s):  
BS Satapathy ◽  
B Duary ◽  
Sanjoy Saha ◽  
S Munda ◽  
D Chatterjee

Wet direct seeding is proved as a viable alternate to conventional transplanting method of rice. Maintenance of optimum population by adopting an appropriate sowing method followed by judicious weed control practices ensures profitability of wet direct seeded rice (W-DSR). A field experiment was carried out to find out a suitable sowing technique and weed control options for enhancing productivity and economics of W-DSR. The W-DSR was infested with twelve numbers of weed species comprising of eight families under different sowing methods. The composition of sedges, broadleaved (BLW) and grassy weeds was 83.07, 11.0 and 5.93%, respectively. Irrespective of sowing methods, weeds such as, Echinochloa glabrescens and Leptochloa chinensis among grasses, Cyperus difformis and Scirpus juncoides among sedges and Lindernia anagallis among BLW were dominant. Drum seeding recorded 6.9 and 12.7% higher gross and net return, respectively than broadcasting, but it was at par with spot seeding. Highest B: C ratio of 2.07 was recorded with drum seeding, whereas spot seeding recorded lowest B: C ratio (1.99). Crop-weed competition caused 31.7% reduction in grain yield with W-DSR. Application of early post-emergent herbicide bensulfuron-methyl + pretilachlor @ 60+600 g/ha at 10 DAS, azimsulfuron @ 35 g/ha at 20 DAS, and bispyribac sodium @ 30 g/ha at 20 DAS recorded increase in grain yield 40.3, 40.1 and 39.8%, respectively over the weedy check. Ready mix bensulfuron-methyl + pretilachlor @ 60+600 g/ha at 10 DAS registered highest B: C ratio (2.16) but it did not vary significantly with bispyribac sodium @ 30 g/ha and azimsulfuron @ 35 g/ha.


2007 ◽  
Vol 25 (3) ◽  
pp. 433-441 ◽  
Author(s):  
J.K.O. Gomes ◽  
P.S.L. Silva ◽  
K.M.B. Silva ◽  
F.F. Rodrigues Filho ◽  
V.G. Santos

Intercropping combined with competitive maize cultivars can reduce the use of herbicides to control weeds. The objective of this work was to evaluate the effects of intercropping cowpea and maize, as well as hand-weeding on maize morphology and yield. The experimental design was in randomized complete blocks, with treatments arranged in split-plots and five replications. The plots consisted of four maize cultivars (BA 8512, BA 9012, EX 4001, EX 6004) and the split-plots consisted of the following treatments: no-weeding; twice hand-weeding (20 and 40 days after sowing); and intercropping with cowpea ('Sempre Verde' cultivar), both maize and cowpea sown at the same time. The variables evaluated were: maize fresh green ears and grain yield; characteristics of internodes, leaves, tassels, ears, grains; plant height and ear insertion height; number of weed plants and species; fresh and dry biomass of weed species and cowpea. Ten weed species were outstanding during the experiment, many of them from the Poaceae family. No interactions were found between weed control method and maize cultivars for most variables evaluated; and plants from hand-weeded split-plots showed superior mean values compared to plants from non-weeded and intercropped split-plots, both not differing from each other. The cowpea was inefficient in controlling weed, reducing the maize yields and not producing any grain. The maize cultivars 'BA 8512' and 'BA 9012 showed the highest mean green ear yield, and the highest grain yield in hand-weeded, no-weeded and intercropped split-plots. On the other hand, the maize cultivar 'EX 6004' showed such high means only in no-weeded and intercropped split-plots. 'EX 4001 presented the worst means in these variables for hand-weeded, no-weeded ant intercropped split-plots.


2000 ◽  
Vol 15 (2) ◽  
pp. 60-67 ◽  
Author(s):  
F.C. Stevenson ◽  
A.M. Johnston ◽  
S.A. Brandt ◽  
L. Townley-Smith

AbstractAlthough crop production and weed growth could change if herbicides and fertilizer inputs were reduced, the short-term impact in an annual cropping system in the Northern Great Plains is not well understood. Data were collected from 14 sites in Saskatchewan, Canada, to investigate the influence of weed control method (cultural vs. herbicides) and N and P fertilizers on crop yield of fall rye, spring wheat, and barley, and the presence and number of weed species. Cultural weed control included 25% greater crop seeding rate, preseeding tillage closer to the time of seeding, and fertilizer N banding in closer proximity to the seed. Four weed species (wild oat, lambsquarters, wild buckwheat, and field penny cress) occurred more frequently in plots with cultural weed control compared with herbicide weed control for all cereal crops. However, straw and grain yields of all crops were unaffected by weed control method at all sites. The addition of fertilizer had a major impact on crop growth and some weed species. Green foxtail occurred more often in unfertilized compared with fertilized plots for all cereal crops. Straw and grain yields of all cereal crops were higher in fertilized compared with unfertilized plots. Crop yield response to fertilizer inputs was not consistent among sites for the three cereal crops. Producers making drastic reductions in fertilizer inputs may experience reductions in crop yields because of limited nutrient levels. However, the results indicate that herbicide inputs could be reduced or eliminated periodically with no short-term yield loss in cereal cropping systems.


2012 ◽  
Vol 60 (1) ◽  
pp. 159-164
Author(s):  
Marian Wesołowski ◽  
Elżbieta Harasim

The objective of the study was to determine the time of occurrence of the emergence, budding, fruiting and seed shedding stages, as well as the degree of advancement of the white goosefoot fruiting and diaspores shedding stages in fodder beet, spring wheat and faba bean crops under mechanical and chemical weed control. Phenological observations were conducted in the years 2000-2002 at 10-day intervals, starting from the day of crop sowing on alluvial soil made of light loam. Chemically weed controlled objects were treated with herbicides: fodder beet - lenacil 80%; spring wheat - MCPA 30% + dicamba 4%; faba bean - linuron 50%. It was proven that the times of occurrence and the scale of the studied phenological stages of white goosefoot depended on the crop species, the in-crop weed control method and the pattern of weather conditions in the study years. White goosefoot had the most favourable conditions of growth in the fodder beet crop. The herbicides in the fodder beet and faba bean crops delayed the emergence and the time of occurrence of successive white goosefoot growth stages. These agents also decreased the degree of diaspores shedding by the weed species studied. The most white goosefoot specimens shed fruits on the mechanically weed controlled plots. The diaspores dissemination was promoted by a warm and moist growing season.


2009 ◽  
Vol 23 (3) ◽  
pp. 438-443 ◽  
Author(s):  
Evan C. Sivesind ◽  
Maryse L. Leblanc ◽  
Daniel C. Cloutier ◽  
Philippe Seguin ◽  
Katrine A. Stewart

Flame weeding is often used for weed control in organic production and other situations where use of herbicides is prohibited or undesirable. Response to cross-flaming was evaluated on five common weed species: common lambsquarters, redroot pigweed, shepherd's-purse, barnyardgrass, and yellow foxtail. Dose-response curves were generated according to species and growth stage. Dicot species were more effectively controlled than monocot species. Common lambsquarters was susceptible to flame treatment with doses required for 95% control (LD95) ranging from 0.9 to 3.3 kg/km with increasing maturity stage. Comparable levels of control in redroot pigweed required higher doses than common lambsquarters, but adequate control was still achieved. Flaming effectively controlled shepherd's-purse at the cotyledon stage (LD95 = 1.2 kg/km). However, the LD95 for weeds with two to five leaves increased to 2.5 kg/km, likely due to the rosette stage of growth, which allowed treated weeds to avoid thermal injury. Control of barnyardgrass and yellow foxtail was poor, with weed survival > 50% for all maturity stages and flaming doses tested. Flame weeding can be an effective and labor-saving weed control method, the extent of which is partially dependent on the weed flora present. Knowledge of the local weed flora and their susceptibility to flame weeding is vital for the effective use of this method.


Author(s):  
Jevgenija Ņečajeva ◽  
Zane Mintāle ◽  
Ieva Dudele ◽  
Anda Isoda-Krasovska ◽  
Jolanta Čūrišķe ◽  
...  

<p class="R-AbstractKeywords"><span lang="EN-GB">Integrated weed management (IWM) is a complex approach to weed control that is based on use of several different methods complementing each other, instead of relying on one single method, like chemical weed control. Weed control methods that can be used as parts of IWM strategy include mechanical weed control, application of herbicides, low tillage, changes in the rate and application time of fertilizers, use of undersown crops and crop rotation. Weed surveys were carried out in 2013 and 2014 in the southeastern part of Latvia. The aim of this study was to assess the effect of crop rotation and other field management practices on weed density and weed species composition using the data collected in the surveys. Survey was carried out in the arable fields of conventional farms within four different size categories. One of the significant factors that explained the variation of weed composition within a field was a proportion of cereals in crop rotation within a four year period. Further surveys are required to estimate the effects of climatic variables. Density-dependence can also be important for practical management decisions for particular weed species and should be investigated.</span></p>


2014 ◽  
Vol 41 (2) ◽  
pp. 124-130 ◽  
Author(s):  
D. Q. Wann ◽  
R. S. Tubbs

ABSTRACT Previous research has shown that mechanical cultivation is the most effective and affordable method of weed control in organic peanut production. However, growers are in need of more information on specific integrated cultivation regimes for effective season-long weed control with minimal hand-weeding requirements. Therefore, field trials were conducted in 2010–2012 to evaluate the effects of various tine and sweep cultivation treatments combined with or without hand-weeding on season-long weed control, stand establishment, and yield and grade of an organically-managed peanut crop. Tine cultivation treatments consisted of no cultivation or weekly cultivations for 5 wks after planting (WAP). Sweep treatments consisted of no cultivation, weekly cultivations (for 5 WAP), cultivations at 2 and 5 WAP only, or cultivation at 5 WAP only. Hand-weeding treatments were no hand-weeding or hand-weeding of the entire plot. There were numerous significant interactions among tine and sweep treatments on weed control. Initial weed species composition greatly affected cultivation effects on overall weed control. Tine cultivation was most effective at controlling annual grass weeds. Sweep cultivation was effective at reducing weeds (Amaranthus spp., southern crabgrass, and Florida pusley), but primarily when tine cultivation was absent. Hand-weeding significantly improved weed control for every weed species every year. Additionally, inclusion of certain cultivation regimes significantly reduced the hand-weeding time requirement over the control. However, cultivation treatments did not improve pod yield or grade in any year. The most significant benefit in cultivation from these data is in the reduction in hand-weeding requirements. Based on this research, a regime consisting of weekly tine cultivations for 5 WAP, combined with two timely sweep cultivations provided the best overall balance of weed control and minimization of hand-weeding. Hand-weeding is the most critical weed control method, followed by tine cultivation, and finally sweep cultivation, which primarily served as an aid in the event of missed tine cultivations or failure.


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