Herbicide-tolerant canola: weed control and yield comparisons in western Canada

2000 ◽  
Vol 80 (3) ◽  
pp. 647-654 ◽  
Author(s):  
K. N. Harker ◽  
R. E. Blackshaw ◽  
K. J. Kirkland ◽  
D. A. Derksen ◽  
D. Wall
Keyword(s):  
Brassica Napus ◽  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
Standard Treatment ◽  
Growth Stages ◽  
Western Canada ◽  
Brassica Napus L ◽  
Standard Application ◽  
Seed Yields

Field experiments were conducted at five western Canadian locations in 1996 and 1997 to compare weed control and canola (Brassica napus L.) seed yields in the three major her-bicide-tolerant canola (HTC) systems. The main objective of this study was to determine if significant weed control and yield advantages could be expected by using herbicides "designated" for HTC compared to a more "standard" application of sethoxydim plus ethametsulfuron. In 3 of 10 site-years, glyphosate in Quest canola and imazethapyr/imazamox in 45A71 canola provided a yield advantage over the standard treatment. The yield advantages were restricted to the Lacombe and Lethbridge sites and ranged from 13 to 39% increases over the sethoxydim plus ethametsulfuron treatments. Among the HTC, weed control was usually greatest with glyphosate, followed by imazethapyr/imazamox, and then glufosinate. Glufosinate efficacy was often restricted due to advanced growth stages on some weeds. The standard treatment of sethoxydim plus ethametsulfuron did not provide better weed control than glyphosate, but in some cases did improve weed control compared to imazethapyr/imazamox or glufosinate. The HTC provide growers with new opportunities for the control of difficult weeds along with the option to employ in-crop herbicides with new modes of action in canola. Key words: Weed management, transgenic canola

When is fall feeding by flea beetles (Phyllotreta spp., Coleoptera: Chrysomelidae) on canola (Brassica napus L.) a problem?

2012 ◽  
Vol 92 (1) ◽  
pp. 97-107
Author(s):  
Juliana J. Soroka ◽  
Larry F. Grenkow
Keyword(s):  
Brassica Napus ◽  
Field Experiments ◽  
Flea Beetle ◽  
Brassica Napus L ◽  
Late Season ◽  
The Third ◽  
Flea Beetles ◽  
Seeding Date ◽  
Seed Yields

Soroka, J. J. and L. F. Grenkow. 2012. When is fall feeding by flea beetles ( Phyllotreta spp., Coleoptera: Chrysomelidae) on canola ( Brassica napus L.) a problem? Can. J. Plant Sci. 92: 97–107. Two cultivars of Brassica napus canola were seeded in mid-May and early June in three field experiments in each of 3 yr near Saskatoon, Saskatchewan, to determine the effects of late-season flea beetle feeding on seed yields. In the first experiment, canola was sprayed with insecticide late in the summer to eliminate naturally-infesting flea beetles. In the second, 1×1×1.5 m screen cages were placed over early- and late-seeded canola at flowering and infested with flea beetles as canola matured. In the third investigation, sleeve cages were placed over individual plants and infested with 100 flea beetles. Flea beetles had no detrimental effects on early-seeded canola in any experiment, but did affect seed yields of late-seeded plots in some trials. Over two cultivars in 1 year, late-seeded plants in cube cages infested with about 350 flea beetles per plant when lower pods were turning from translucent to green in colour reduced yield by 241 kg ha−1 over control yields. Seed weights in these late-seeded plots were decreased from 2.68 g per 1000 seeds in uninfested cages to 2.44 g per 1000 seeds in infested cages. Populations of 100 flea beetles per plant in sleeve cages had no effect on harvest parameters in any seeding date or year.

Reduced-Herbicide Weed Management Systems for No-Tillage Corn (Zea mays) in a Hairy Vetch (Vicia villosa) Cover Crop

1993 ◽  
Vol 7 (4) ◽  
pp. 879-883 ◽  
Author(s):  
John R. Teasdale
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Cover Crop ◽  
Field Experiments ◽  
Standard Treatment ◽  
Corn Yield ◽  
No Tillage ◽  
Hairy Vetch ◽  
Treatment Control ◽  
Vicia Villosa

Weed management treatments with various degrees of herbicide inputs were applied with or without a hairy vetch cover crop to no-tillage corn in four field experiments at Beltsville, MD. A hairy vetch living mulch in the no-treatment control or a dead mulch in the mowed treatment improved weed control during the first 6 wk of the season but weed control deteriorated in these treatments thereafter. Competition from weeds and/or uncontrolled vetch in these treatments without herbicides reduced corn yield in three of four years by an average of 46% compared with a standard PRE herbicide treatment of 0.6 kg ai/ha of paraquat plus 1.1 kg ai/ha of atrazine plus 2.2 kg ai/ha of metolachlor. Reducing atrazine and metolachlor to one-fourth the rate of the standard treatment in the absence of cover crop reduced weed control in three of four years and corn yield in two of four years compared with the standard treatment. Hairy vetch had little influence on weed control or corn yield with any herbicide treatments.

Effect of integrated weed management and nitrogen fertilization on the performance of rice under flood-prone lowland conditions

1997 ◽  
Vol 129 (4) ◽  
pp. 409-418 ◽  
Author(s):  
A. R. SHARMA
Keyword(s):  
Grain Yield ◽  
Weed Control ◽  
Water Depth ◽  
Weed Management ◽  
Field Experiments ◽  
Conventional Tillage ◽  
N Fertilizer ◽  
Integrated Weed Management ◽  
Growth Stages ◽  
Crop Cultivation

Field experiments were conducted at Cuttack, India during 1991–94 to study the effect of tillage, methods of crop establishment and weed control at varying levels of N fertilizer on the performance of rice under flood-prone lowland conditions (0·60 cm water depth). The loss in grain yield of direct-sown rice caused by unchecked weed growth ranged from 18·2 to 59·2% in the different years, and was greater when N fertilizer was applied and when the conventional practice of ploughing the fields just before sowing was followed. Increasing the number of tillage operations before sowing improved the crop stand, reduced weed infestation and, thereby, increased the yield significantly compared with that achieved by conventional tillage. Summer ploughing rather than conventional tillage decreased weed dry weight at harvest by 15·8–53·2% and increased grain yield by 47·4–56·3%. A pre-emergence application of thiobencarb at 2·0 kg/ha, hand weeding once at 20 days of growth and post-establishment inter-crop cultivation at 37–42 days provided effective weed control and increased yield by 32·7–34·7, 36·7 and 28·7–83·9%, respectively. The efficiency of weed control and the resulting increase in rice yield were comparatively greater under puddling than with inter-crop cultivation and herbicide application. The loss in yield due to weeds was negligible when the crop was transplanted due to the incorporation of weeds during puddling and a greater water depth in the later growth stages. Therefore, the grain yield of rice was highest with transplanting followed closely by the direct-sown crop with post-establishment inter-crop cultivation. The response of direct-sown rice to N fertilization up to 60 kg N/ha decreased with fewer ploughings when no weed control measures were adopted. However, the grain yield increased significantly with N application up to 40 kg N/ha when weeds were controlled by cultural or chemical methods. The results suggested that an integrated weed management strategy involving summer ploughing, thiobencarb application and inter-crop cultivation is essential for effective weed control in direct-sown, flood-prone, lowland rice, in order to ensure higher N-use efficiency and crop productivity.

Competition and control of weeds in soybean

Weed Science ◽  
1999 ◽  
Vol 47 (1) ◽  
pp. 107-111 ◽  
Author(s):  
Rajender Singh Chhokar ◽  
Rajender Singh Balyan
Keyword(s):  
Weed Control ◽  
Broad Spectrum ◽  
Weed Management ◽  
Critical Period ◽  
Management Practices ◽  
Field Experiments ◽  
Growth Stages ◽  
Single Application ◽  
Reduced Rate ◽  
And Control

Two field experiments were carried out from 1993 to 1995 to evaluate the critical period of weed control and to develop suitable weed management practices for jungle rice, horse purslane, and cockscomb in soybean. Horse purslane was more competitive during early growth stages (up to 45 days after sowing [DAS]) and cockscomb was more competitive during later growth stages, whereas jungle rice was competitive throughout the growing season. The critical period of weed control was found to be 30 to 45 DAS. Weed-free maintenance up to 45 DAS resulted in a 74% increase in grain yield of soybean over the unweeded control. Keeping soybean weed free for 45 d or allowing weeds to remain in the crop for less than 30 d resulted in no significant yield loss. Sequential application of a reduced rate of soil-applied trifluralin 1.0 kg ha–1(0.67 ×) with postemergence fluazifop 0.75 kg ha–1(0.75 ×) or a reduced rate of soil-applied trifluralin or pendimethalin at 1.0 kg ha–1(0.67 ×) followed by hand hoeing 35 DAS provided better control of a broad spectrum of weeds than a single application of a postemergence herbicide applied at reduced or recommended rates. Integration of reduced rates of soil-applied herbicides with post-emergence herbicides or hand hoeing 35 DAS produced soybean yields similar to the hand-weeded treatment. Compared to the weed-free or integrated weed control, a single application of soil-applied or postemergence herbicide did not control a broad spectrum of weeds and reduced soybean yield.

The effectiveness of flame weeding and cultivation on weed control, yield and yield components of organic soybean as influenced by manure application

2015 ◽  
Vol 31 (4) ◽  
pp. 288-299 ◽  
Author(s):  
Strahinja Stepanovic ◽  
Avishek Datta ◽  
Brian Neilson ◽  
Chris Bruening ◽  
Charles Shapiro ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Yield Components ◽  
Field Experiments ◽  
Leaf Growth ◽  
Growth Stages ◽  
Soybean Production ◽  
Crop Injury ◽  
Yield And Yield Components ◽  
Soybean Plants

AbstractPropane flaming in combination with cultivation could be a potential alternative tool for weed control in organic soybean production. Field experiments were conducted at the Haskell Agricultural Laboratory of the University of Nebraska-Lincoln (UNL), Concord, NE in 2010, 2011 and 2012 to determine the level of weed control and the response of soybean grain yield and its components to flaming and cultivation within two fertility regimes (FRs) (with and without manure) utilizing flaming equipment developed at the UNL. The treatments included: weed-free control, weedy season-long and different combinations of banded flaming (intra-row), broadcast flaming and mechanical cultivation (inter-row). The treatments were applied at VC (unfolded cotyledon) and V4–V5 (4-leaf–5-leaf) growth stages. Propane doses were 20 and 45 kg ha−1 for the banded and broadcast flaming treatments, respectively. The data were collected for visual ratings of crop injury and weed control at 7 and 28 days after treatment (DAT) at V4–V5 growth stages, weed dry matter at 60 DAT, crop yield and yield components. The annual application of 101 t ha−1 manure did not alter weed community or influence the effectiveness of weed management treatment; however, it decreased soybean yield by 0.25 t ha−1 through an increased weed biomass of 0.16 t ha−1. The weed-free control plots yielded 4.15 t ha−1. The combination of mechanical cultivation and banded flaming applied twice (at VC and V4–V5) was the best treatment resulting in 80–82% weed control and 6–9% crop injury at 28 DAT and 3.41–3.67 t ha−1 yield. Cultivation conducted twice provided only 19% weed control at 28 DAT and 1.75 t ha−1 yield. Soybean plants recovered well after all flaming treatments, with the exception of broadcast flaming conducted twice (28% crop injury at 28 DAT). Combining flaming with cultivation has a potential to effectively control weeds in organic soybean production across a range of FRs.

Bio-efficacy of post emergence herbicides in boro rice nursery as well as main field and their residual effects on non-target microorganisms

2020 ◽  
Vol 57 (3) ◽  
pp. 199-210
Author(s):  
Rajib Kundu ◽  
Mousumi Mondal ◽  
Sourav Garai ◽  
Ramyajit Mondal ◽  
Ratneswar Poddar
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
Block Design ◽  
Resistance Index ◽  
Residual Effects ◽  
Cost Ratio ◽  
Main Field ◽  
Weed Species ◽  
Similar Treatment

Field experiments were conducted at research farm of Bidhan Chandra Krishi Viswavidyalaya, Kalyani, West Bengal, India (22°97' N latitude and 88°44' E longitude, 9.75 m above mean sea level) under natural weed infestations in boro season rice (nursery bed as well as main field) during 2017-18 and 2018-19 to evaluate the herbicidal effects on weed floras, yield, non-target soil organisms to optimize the herbicide use for sustainable rice-production. Seven weed control treatments including three doses of bispyribac-sodium 10% SC (150,200, and 250 ml ha-1), two doses of fenoxaprop-p-ethyl 9.3% EC (500 and 625 ml ha-1), one weed free and weedy check were laid out in a randomized complete block design, replicated thrice. Among the tested herbicides, bispyribac-sodium with its highest dose (250 ml ha-1) resulted in maximum weed control efficiency, treatment efficiency index and crop resistance index irrespective of weed species and dates of observation in both nursery as well as main field. Similar treatment also revealed maximum grain yield (5.20 t ha-1), which was 38.38% higher than control, closely followed by Fenoxaprop-p-ethyl (625 ml ha-1) had high efficacy against grasses, sedge and broadleaf weed flora. Maximum net return (Rs. 48765 ha-1) and benefit cost ratio (1.72) were obtained from the treatment which received bispyribac-sodium @ 250 ml ha-1. Based on overall performance, the bispyribac-sodium (250 ml ha-1) may be considered as the best herbicide treatment for weed management in transplanted rice as well as nursery bed.

Impact of cultivars and herbicides on weed management in alfalfa

2006 ◽  
Vol 86 (3) ◽  
pp. 875-885 ◽  
Author(s):  
J. R. Moyer ◽  
S. N. Acharya
Keyword(s):  
British Columbia ◽  
Weed Control ◽  
Weed Management ◽  
Forage Quality ◽  
Western Canada ◽  
Downy Brome ◽  
Weed Species ◽  
Standard Type ◽  
Southern Alberta ◽  
Medicago Sativa L

Weeds, especially dandelion (Taraxacum officinale Weber in F.H. Wigg.), tend to infest a forage alfalfa (Medicago sativa L.) stand 2 to 4 yr after establishment. To develop better weed management systems, experiments were conducted at Lethbridge, Alberta, from 1995 to 2002 and Creston, British Columbia, from 1998 to 2001, which included the alfalfa cultivars Beaver (standard type) and AC Blue J (Flemish type) and annual applications of metribuzin and hexazinone. These herbicides are registered for weed control in irrigated alfalfa in Alberta and alfalfa grown for seed. In addition, two sulfonylurea herbicides, metsulfuron and sulfosulfuron, and glyphosate were included. All of the herbicides except glyphosate controlled or suppressed dandelion and mustard family weeds. Metsulfuron at 5 g a.i. ha-1 almost completely controlled dandelion at both locations. However, after metsulfuron application at Lethbridge, dandelion was replaced with an infestation of downy brome, which is unpalatable for cattle. None of the herbicides increased total forage (alfalfa + weed) yield, and in some instances herbicides reduced forage quality by causing a shift from a palatable to an unpalatable weed species. However, it was observed that AC Blue J consistently yielded more than Beaver, and weed biomass was consistently less in the higher-yielding cultivar. AC Blue J was developed primarily for the irrigated area in southern Alberta and for southern British Columbia. Therefore, additional experiments should be conducted to determine which alfalfa cultivars have the greatest ability to compete with weeds in other regions of western Canada. Key words: Alfalfa yield, dandelion, forage quality, weed control

Weed Management in Southeastern Peanut (Arachis hypogaea) with AC 263,222

1996 ◽  
Vol 10 (1) ◽  
pp. 145-152 ◽  
Author(s):  
John S. Richburg ◽  
John W. Wilcut ◽  
Daniel L. Colvin ◽  
Gerald R. Wiley
Keyword(s):  
Weed Control ◽  
Arachis Hypogaea ◽  
Weed Management ◽  
Field Experiments ◽  
Common Ragweed ◽  
Yellow Nutsedge ◽  
Application Rates ◽  
Ac 263,222

Field experiments conducted at four locations in Georgia and two locations in Florida during 1992 and 1993 evaluated AC 263,222 application rates and timings, systems, and mixtures for weed control, peanut injury, and yield. All rates of AC 263,222 applied early POST (EPOST) or POST controlledIpomoeamorningglories and smallflower morningglory at least 90%, and purple and yellow nutsedge at least 81%. Florida beggarweed and sicklepod control generally was highest when metolachlor was applied PPI followed by AC 263,222 applied EPOST at 71 g/ha, AC 263,222 at 27 or 36 g/ha plus bentazon plus paraquat applied POST, or with bentazon plus paraquat applied EPOST followed by AC 263,222 applied POST at 36 or 53 g/ha. Acifluorfen and acifluorfen plus bentazon reduced Florida beggarweed and sicklepod control at several locations when applied in mixture with AC 263,222. Common ragweed and hairy indigo control were 85 to 95% with bentazon plus paraquat applied EPOST followed by AC 263,222 applied POST at 36 or 53 g/ha. Highest peanut yields were obtained with treatments providing high levels of weed control.

scholarly journals The Critical Period for Weed Control (CPWC) in Potato (Solanum tuberosum L.)

2015 ◽  
Vol 43 (2) ◽  
pp. 355-360 ◽  
Author(s):  
Dogan ISIK ◽  
Adem AKCA ◽  
Emine KAYA ALTOP ◽  
Nihat TURSUN ◽  
Husrev MENNAN
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Critical Period ◽  
Field Experiments ◽  
Yield Loss ◽  
Cropping Systems ◽  
Control Period ◽  
Relative Yield ◽  
Yield Data ◽  
Weed Interference

Accurate assessment of crop-weed control period is an essential part for planning an effective weed management for cropping systems. Field experiments were conducted during the seasonal growing periods of potato in 2012 and 2013 in Kayseri, Turkey to assess critical period for weed control (CPWC) in potato. A four parameter log-logistic model was used to assist in monitoring and analysing two sets of related, relative crop yield. Data was obtained during the periods of increased weed interference and as a comparison, during weed-free periods. In both years, the relative yield of potato decreased with a longer period of weed-interference whereas increased with increasing length of weed free period. In 2012, the CPWC ranged from 112 to 1014 GDD (Growing Degree Days) which corresponded to 8 to 66 days after crop emergence (DAE) and between 135-958 GDD (10 to 63 DAE) in the following year based on a 5% acceptable yield loss. Weed-free conditions needed to be established as early as the first week after crop emergence and maintained as late as ten weeks after crop emergence to avoid more than 5% yield loss in the potato. The results suggest that CPWC could well assist potato producers to significantly reduce the expense of their weed management programs as well as improving its efficacy.

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