scholarly journals Hoeing as a Possibility for Mechanical Weed Control in Winter Oilseed Rape (Brassica napus L.)

Crops ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 1-13
Author(s):  
Sebastian Schwabe ◽  
Sabine Gruber ◽  
Wilhelm Claupein
Keyword(s):  
Brassica Napus ◽  
Data Collection ◽  
Weed Control ◽  
Oilseed Rape ◽  
Chemical Control ◽  
Plant Density ◽  
The Other ◽  
Herbicide Application ◽  
Weed Biomass ◽  
Weed Plant

The framework conditions for chemical weed control in oilseed rape (OSR) are becoming increasingly unfavorable in Central Europe. On the one hand, weed resistance is spreading and, on the other, there is a growing social desire to reduce or eliminate the use of chemical crop protection products. In a field experiment, hoeing, as a weed control measure performed two times per growing season (one time in autumn and one time in spring) in oilseed rape (Brassica napus; two varieties), was compared to chemical control by herbicides and a combination of hoeing and herbicide application (five treatments altogether). The chemical control by herbicides consisted of a broad-spectrum pre-emergence treatment and a post-emergence graminicide application. The trial was set up in each of three periods (years 2014/2015, 2015/2016, and 2016/2017) at the experimental station Ihinger Hof, University of Hohenheim, Stuttgart, Germany. The effect of the treatments on weed plant density, weed biomass at the time of harvesting, and on OSR grain yield was investigated. Weed plant density was measured four times per trial year, each time before and after hoeing. In 2015/2016 after spring hoeing, and in 2016/2017 at all data collection times, weed plant density was significantly higher in hoeing without herbicide application than in the other variants. No significant differences occurred at the other data collection times. The weed plant density ranged from 0.5 to 57.8 plants m−2. Regardless of the trial year, pure hoeing always resulted in a significantly higher weed biomass at the time of harvesting than the herbicide applications or the combinations. The weed biomass at the time of harvesting ranged between 0.1 and 54.7 g m−2. No significant differences in grain yield between hoeing and herbicide application occurred in all three trial years. According to the results, hoeing is a suitable extension of existing integrated weed control strategies in OSR.

scholarly journals 009 Annual Weed Chemical Control in Asparagus

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 442C-442
Author(s):  
Arturo López-Carvajal ◽  
R. Leonel Grijalva-Contreras ◽  
Cristóbal Navarro-Ainza ◽  
Gerardo Martínez-Díaz
Keyword(s):  
Weed Control ◽  
Water Flow ◽  
Chemical Control ◽  
Control Plot ◽  
Portulaca Oleracea ◽  
The Other ◽  
Herbicide Application ◽  
Plant Toxicity ◽  
Annual Grasses ◽  
Amaranthus Spp

Approximately 50% of the asparagus plantations (3000 ha) in the Caborca, Sonora, area is furrow-irrigated. Under these conditions it is common to observe growing weeds in the furrow section, which impede water flow and compete for resources with the asparagus plant, finally reducing spear production and quality. Hence, the objective of this study was to validate herbicides to achieve an efficient annual weed control in the asparagus plantations. The validation plot was established in May 1998 on a commercial asparagus plantation that was highly infested mostly with annual grasses (Echinochloa colonum and E. crusgalli), and Amaranthus spp. and Portulaca oleracea as a secondary weeds. The herbicides and rates tested were: Prometrine (2 L·ha-1), Norflurazon (4 kg), Metribuzin (0.5 kg), Linuron (2 kg), and the control plot (no herbicide application). All the tested products showed significant weed control percentages compared with the control plot. Norflurazon, however, was clearly superior to the other herbicides, exhibiting a 100% control for a period of almost 18 weeks. Metribuzin had a 85% control for 12 weeks. Linuron and Prometrine exhibited a 68% and 47% control, respectively, for up to 12 weeks. Plant toxicity symptoms on the asparagus plant were not observed with any of the tested herbicides.

Effect of Imazethapyr on Legumes and the Effect of Legumes on Weeds

1994 ◽  
Vol 8 (3) ◽  
pp. 536-540 ◽  
Author(s):  
Robert G. Wilson
Keyword(s):  
Weed Control ◽  
Red Clover ◽  
The Other ◽  
Birdsfoot Trefoil ◽  
Weed Biomass

A three-year experiment was conducted near Scottsbluff, NE, to evaluate the selectivity of POST-applied imazethapyr for weed control in alfalfa, birdsfoot trefoil, cicer milkvetch, red clover, sainfoin, and yellow sweetclover. Imazethapyr injured all legumes 15 DAT. Imazethapyr also reduced the height of birdsfoot trefoil, cicer milkvetch, red clover, and yellow sweeclover 28 DAT. Legume first cutting yields were not reduced by imazethapyr and with alfalfa, birdsfoot trefoil, cicer milkvetch, and sainfoin, first cutting yields were increased by imazethapyr. Imazethapyr reduced weed biomass in all legume seedings. Weed biomass in new seedings of alfalfa was reduced more than that of the other legumes.

Effects of high plant populations on the growth and yield of winter oilseed rape (Brassica napus)

1999 ◽  
Vol 132 (2) ◽  
pp. 173-180 ◽  
Author(s):  
J. E. LEACH ◽  
H. J. STEVENSON ◽  
A. J. RAINBOW ◽  
L. A. MULLEN
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Plant Density ◽  
High Density ◽  
Growth And Yield ◽  
Winter Oilseed Rape ◽  
Plant Populations ◽  
Rothamsted Experimental Station ◽  
Plant Densities ◽  
Very High

The effects of plant density on the growth and yield of winter oilseed rape (Brassica napus) were examined in a series of five multifactorial experiments at Rothamsted Experimental Station between 1984 and 1989. Plant densities, manipulated by changing the seed rate and row spacing, or because of overwinter losses, ranged from 13·5 to 372 plants/m2. Normalized yields for the multifactorial plots increased with densities up to 50–60 plants/m2. In very high density plots in 1987/88, yield decreased as density increased >150 plants/m2. Plants grown at high density had fewer pod-bearing branches per plant but produced more branches/m2. Branch dry matter (DM) per plant was decreased by 42%, the number of fertile pods per plant and pod DM/plant by 37%. There was no effect of density on the number or DM of pods/m2. Over 74% of the fertile pods were carried on the terminal and uppermost branches of plants grown at high density in 1987/88 compared with only 34% in plants grown at low density in 1988/89. Seed DM/plant decreased with increase in density but seed size (1000-seed weight) increased. There was no effect of density on seed glucosinolate or oil contents.

scholarly journals Selectivity of the herbicide linuron sprayed in pre-emergence and post-early in carrot

2017 ◽  
Vol 38 (3) ◽  
pp. 1201
Author(s):  
Núbia Maria Correia ◽  
Agnaldo Donizete Ferreira de Carvalho
Keyword(s):  
Experimental Design ◽  
Weed Control ◽  
Chemical Treatment ◽  
Commercial Production ◽  
Additional Treatment ◽  
The Other ◽  
Cultivated Plants ◽  
Herbicide Application ◽  
Time Of Application ◽  
Carrot Plant

Herbicide application is a method for weed control in carrot crops. However, the choice of the chemical treatment (herbicide, association of products, dose, and time of application) should consider its selectivity to the crop. It is desired to analyze the selectivity of linuron for carrot plants, when sprayed on pre-emergence and post-early cultivated plants. Two experiments were carried out in the field in an area of the commercial production of carrots, one with the Verano cultivar and the other with BRS Planalto. Both experiments included an experimental design with randomized blocks in a factorial 2 x 4 + 1 with six and four replications for the experiments with Verano and BRS Planalto, respectively. The herbicide linuron (675 and 990 g a.i. ha-1) was sprayed at four times, counting from the carrot sowing day: in the pre-emergence of the crop at 0, 3, and 6 days after sowing (DAS) and in the post-early emergence at 9 DAS, when the plants had 1 or 2 cotyledons. An untreated control was maintained as an additional treatment. Linuron was selective for the carrot plant cultivars Verano and BRS Planalto, in both doses tested, when sprayed in the pre-emergence, up to six days after sowing, and in the post-early (plants with 1 or 2 cotyledon leaves) at nine days after sowing.

The influence of winter oilseed rape (Brassica napus ssp. oleifera var. biennis) canopy size on grass weed growth and grass weed seed return

2007 ◽  
Vol 145 (4) ◽  
pp. 313-327 ◽  
Author(s):  
L. C. SIM ◽  
R. J. FROUD-WILLIAMS ◽  
M. J. GOODING
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Plant Density ◽  
Sowing Date ◽  
Research Unit ◽  
Good Evidence ◽  
Seed Rate ◽  
Date Seed ◽  
Canopy Size ◽  
Grass Weed

SUMMARYFour experiments conducted over three seasons (2002–05) at the Crops Research Unit, University of Reading, investigated effects of canopy management of autumn sown oilseed rape (Brassica napus L. ssp. oleifera var. biennis (DC.) Metzg.) on competition with grass weeds. Emphasis was placed on the effect of the crop on the weeds.Rape canopy size was manipulated using sowing date, seed rate and the application of autumn fertilizer. Lolium multiflorum Lam., L.×boucheanum Kunth and Alopecurus myosuroides Huds. were sown as indicative grass weeds.The effects of sowing date, seed rate and autumn nitrogen on crop competitive ability were correlated with rape biomass and fractional interception of photosynthetically active radiation (PAR) by the rape floral layer, to the extent that by spring there was good evidence of crop: weed replacement.An increase in seed rate up to the highest plant densities tested increased both rape biomass and competitiveness, e.g. in 2002/3, L. multiflorum head density was reduced from 539 to 245 heads/m2 and spikelet density from 13 170 to 5960 spikelets/m2 when rape plant density was increased from 16 to 81 plants/m2. Spikelets/head of Lolium spp. was little affected by rape seed rate, but the length of heads of A. myosuroides was reduced by 9% when plant density was increased from 29–51 plants/m2.Autumn nitrogen increased rape biomass and reduced L. multiflorum head density (415 and 336 heads/m2 without and with autumn nitrogen, respectively) and spikelet density (9990 and 8220 spikelets/m2 without and with autumn nitrogen, respectively). The number of spikelets/head was not significantly affected by autumn nitrogen.Early sowing could increase biomass and competitiveness, but poor crop establishment sometimes overrode the effect. Where crop and weed establishment was similar for both sowing dates, a 2-week delay (i.e. early September to mid-September) increased L. multiflorum head density from 226 to 633 heads/m2 and spikelet density from 5780 to 15 060 spikelets/m2.

Effect of Imazethapyr on Perennial Grasses

1995 ◽  
Vol 9 (1) ◽  
pp. 187-191 ◽  
Author(s):  
Robert G. Wilson
Keyword(s):  
Weed Control ◽  
Perennial Grasses ◽  
The Other ◽  
Blue Grama ◽  
Weed Biomass ◽  
Intermediate Wheatgrass ◽  
Little Bluestem ◽  
Western Wheatgrass ◽  
Russian Wildrye

Experiments were conducted near Scottsbluff, NE in 1991 and 1992 to evaluate the selectivity of imazethapyr for weed control in blue grama, intermediate wheatgrass, little bluestem, Russian wildrye, switchgrass, and western wheatgrass. Imazethapyr reduced weed biomass in all seedings and injured all perennial grasses 12 days after treatment (DAT). Imazethapyr reduced the height of intermediate wheatgrass, Russian wildrye, and switchgrass 35 DAT. Russian wildrye, and switchgrass biomass 50 DAT was reduced by imazethapyr. Weed biomass in new seedings of intermediate wheatgrass and western wheatgrass were reduced more than that of the other grasses.

The Critical Period of Weed Control for Lentil in Western Canada

Weed Science ◽  
2011 ◽  
Vol 59 (4) ◽  
pp. 517-526 ◽  
Author(s):  
L. K. Fedoruk ◽  
E. N. Johnson ◽  
S. J. Shirtliffe
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Inverse Relationship ◽  
Yield Loss ◽  
Western Canada ◽  
Crop Canopy ◽  
Herbicide Application ◽  
Weed Biomass ◽  
Weed Interference ◽  
Residual Herbicide

Weed control in lentil is difficult because lentil is a poor competitor with weeds and few POST broadleaf herbicides are available. Imadazolinone-tolerant lentils have more herbicide options, but the optimum timing for herbicide application is not known. The critical period of weed control (CPWC) is the period in a crop's life cycle when weeds must be controlled in order to prevent yield loss. The objective of this research was to determine the CPWC for lentil. We made lentil remain weedy or weed-free from 0 to 11 aboveground nodes to investigate the durations of weed interference and weed-free period, respectively. It was found that lentil has a CPWC beginning at the five-node stage and continuing to the 10-node stage. There was an inverse relationship between weed biomass and lentil yield; that is, lentil yield was highest when weed biomass is minimal. We propose that the CPWC begins when weeds start to accumulate significant biomass and ends with crop canopy closure. Therefore, to maximize lentil yields, growers should consider using a POST residual herbicide that can control weeds during the CPWC.

scholarly journals Innovative Herbicide Application Methods and Their Potential for Use in the Nursery and Landscape Industries

1994 ◽  
Vol 4 (4) ◽  
pp. 345-350 ◽  
Author(s):  
Jeffrey F. Derr
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Chemical Control ◽  
Crop Production ◽  
Slow Release ◽  
Application Rate ◽  
Management Option ◽  
Herbicide Application ◽  
Application Methods ◽  
Improved Methods

Chemical weed control is an important weed management option in nursery crop production and landscape maintenance. Improved methods of herbicide delivery can increase efficacy of chemical control and minimize off-site movement, applicator exposure, and incorrect herbicide application. Certain innovative technologies show potential for addressing these issues in the nursery industry. Slow-release herbicide tablets have shown promise in container production. Horticultural collars, treated paper, and treated mulch are potential ways of applying herbicides in container crop production and/or landscape maintenance. Horticultural collars contain herbicides between two layers of a carrier such as a landscape fabric. A rapidly degradable paper can be pretreated with an herbicide for a precise application rate. Mulch can be treated with a herbicide prior to use in the landscape for improved weed control. Herbicides applied through the clip-cut pruning system could control weeds selectively in nurseries and landscapes. Each of these methods may address one or more concerns about off-site movement, calibration, and applicator exposure to pesticides.

scholarly journals SELECTIVE BROADLEAF WEED CONTROL IN GROUNDCOVERS

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 498A-498 ◽  
Author(s):  
Christina Walsworth ◽  
Edward Bush ◽  
Ronald Strahan ◽  
Ann Gray
Keyword(s):  
Weed Control ◽  
Bare Soil ◽  
Amaranthus Retroflexus ◽  
The Other ◽  
Economic Issue ◽  
Herbicide Application ◽  
Weed Species ◽  
Control Data ◽  
Sesbania Exaltata ◽  
Ophiopogon Japonicus

Selective broadleaf weed control is a major economic issue facing commercial landscapers and homeowners alike. Minimal selective post-emergent weed research has been successful in controlling landscape weeds. The objectives of this experiment were to determine the efficacy of seven selective broadleaf herbicides [nicosulfuron (0.66 oz/acre), flumioxazin (8 oz/acre), penoxsulam (2.3 fl oz/acre), bensulfuron (1.66 oz/acre), glyphosate (1% by volume), sulfentrazone (8 fl oz/acre), trifloxysulfuron (0.56 oz/acre) and the control] and to determine the ornamental phytotoxicity on three groundcover species (Liriope muscari, Ophiopogon japonicus, and Trachelospermum asiaticum). A RCBD design was used with five blocks. Each block was split establishing either mulched or bare soil plots (nonmulched). The ground-covers were established three months before herbicide application. On 29 June 2005, four weed species were evenly seeded into the blocks with one hundred seeds each of Sesbania exaltata, Ipomea hederacea, Amaranthus retroflexus, and Euphorbia maculata. Herbicides were applied using a CO2 backpack type sprayer on 6 Sept. 2005. Plant and weed control data were taken to evaluate phytotoxicity and efficacy at 0, 1, 7, 14, and 28 DAT. On 27 Oct. 2005, weeds were harvested from each plot and dried for a minimum of 48 h and weighed. No significant differences in phytotoxicity were observed on either Liriope muscari or Trachelospermum asiaticum. However, there was a significant increase in phytotoxicity exhibited by the Ophiopogon japonicus treated with sulfentrazone compared to all of the other herbicides. Glyphosate demonstrated the best overall control of all broadleaf weeds except Sesbania, while trifloxysulfuron showed the best control of Sesbania. There were no significant differences in herbicide efficacy between the mulched and nonmulched plots. Further research is being done to measure the effects of herbicide efficacy and phytotoxicity in 2006.

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