Seeding rate and cultivar effects on canola (Brassica napus) competition with volunteer wheat (Triticum aestivum)

2016 ◽  
Vol 67 (8) ◽  
pp. 857 ◽  
Author(s):  
Deirdre Lemerle ◽  
David J. Luckett ◽  
Eric A. Koetz ◽  
Trent Potter ◽  
Hanwen Wu
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Weed Management ◽  
Potential Interaction ◽  
Weed Suppression ◽  
Yield Losses ◽  
Seeding Rate ◽  
Brassica Napus L ◽  
Rotational Crop ◽  
The Impact

Canola (Brassica napus L.) is an important rotational crop in the temperate cropping zone of southern Australia. Herbicide-resistant weeds are rapidly spreading and reducing canola grain yield and quality. Crop competition is a useful tool for reducing weed costs and dependence on herbicides, and retarding the spread of herbicide resistance. The potential interaction of canola seeding rate and cultivar for weed management has not been quantified in Australia. A field experiment was conducted in three environments to examine the impact of two contrasting canola cultivars (a low vigour type and a high vigour hybrid) at four seeding rates (10–100 plants/m2) on volunteer wheat (~50 plants/m2). Significant but variable effects of crop seeding rate, cultivar and weed were detected on canola density and grain yield, and on the suppression of volunteer wheat. The canola hybrids suppressed volunteer wheat more than the less vigorous cultivars in all the experiments. There was no benefit of increasing canola seeding rate above the normally recommended rate of 40 plants/m2 for weed suppression. The seed production of volunteer wheat on average doubled when canola density dropped from 40 to 10 plants/m2. Treatment effects on canola grain yield losses from weeds were less than those on weed suppression. The grain yield of both cultivars was reduced between 30% and 40% with weeds at a canola density of 40 plants/m2 and plateaued above this density in weedy conditions. Maintaining canola plant establishment and using competitive cultivars is critical to avoiding weed seedbank replenishment, and reducing canola yield losses from weed competition.

Competitive ability of Australian canola (Brassica napus) genotypes for weed management

2014 ◽  
Vol 65 (12) ◽  
pp. 1300 ◽  
Author(s):  
Deirdre Lemerle ◽  
David J. Luckett ◽  
Peter Lockley ◽  
Eric Koetz ◽  
Hanwen Wu
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Weed Management ◽  
Competitive Ability ◽  
Cropping Systems ◽  
Low Cost ◽  
Integrated Weed Management ◽  
Brassica Napus L ◽  
Herbicide Resistant ◽  
Weed Growth

Canola (Brassica napus L.) is an important break crop in Australian cropping systems but weeds are a major cost to production and herbicide-resistant weeds are spreading. The potential competitive ability of canola genotypes to both suppress weed growth and maintain grain yield and quality in the presence of weeds has not been determined in Australia. Two experiments examined the range in competitive ability of 16 B. napus genotypes against annual ryegrass (Lolium rigidum Gaud.) and volunteer wheat (Triticum aestivum L.) over two contrasting seasons. Weed biomass at flowering was generally reduced 50% more in the presence of the strongly competitive genotypes than the least competitive, and this has significant benefits for lower weed seed production and reduced seedbank replenishment. Suppression of weed growth was negatively correlated with crop biomass. Significant differences in grain yield of canola were recorded between weedy and weed-free plots, depending on crop genotype, presence of weeds and season. Crop yield tolerance (where 0% = no tolerance and 100% = complete tolerance) to ryegrass competition ranged from 0% (e.g. with CB-Argyle) to 30–40% (e.g. with the hybrids 46Y78 and Hyola-50) in the dry season of 2009. Yield tolerance was higher (50–100%) with the lower densities of volunteer wheat and in the 2010 season. The range between genotypes was similar for both conditions. The hybrids and AV-Garnet were higher yielding and more competitive than the triazine-tolerant cultivars. The ranking of genotypes for competitiveness was strongly influenced by seasonal conditions; some genotypes were consistently more competitive than others. Competitive crops are a low-cost tactic for integrated weed management to reduce dependence on herbicides and retard the spread of herbicide-resistant weeds.

scholarly journals The impact of cultivar resistance and fungicide treatment on mycotoxin content in grain and yield losses caused by Fusarium head blight in wheat

2010 ◽  
Vol 46 (No. 1) ◽  
pp. 21-26 ◽  
Author(s):  
V. Šíp ◽  
J. Chrpová ◽  
O. Veškrna ◽  
L. Bobková
Keyword(s):  
Grain Yield ◽  
Fusarium Head Blight ◽  
Field Experiments ◽  
Yield Loss ◽  
Joint Effect ◽  
Yield Losses ◽  
Cultivar Resistance ◽  
Head Blight ◽  
Fungicide Treatment ◽  
The Impact

Reactions to artificial infection with Fusarium graminearum isolates and a new fungicide Swing Top were studied in nine winter wheat cultivars evaluated in field experiments at two sites for three years for expression of symptoms, deoxynivalenol (DON) content in grain and grain yield. The results demonstrate a pronounced and relatively stable effect of cultivar resistance on reducing head blight, grain yield losses and contamination of grain by the mycotoxin DON. It is advantageous that the moderate level of resistance to Fusarium head blight (FHB) was detected also in two commonly grown Czech cultivars Sakura and Simila. Average fungicide efficacy for DON was 49.5% and 63.9% for a reduction in yield loss, however, it was found highly variable in different years and sites. The joint effect of cultivar resistance and fungicide treatment was 86.5% for DON and even 95.4% for reducing the yield loss. A very high risk was documented for susceptible cultivars and also the effects of medium responsive cultivars were found to be highly variable in different environments and therefore not guaranteeing sufficient protection against FHB under different conditions.

Can hemp hurd or paper mulch and biochar application improve weed management in matted-row strawberry production systems?

2021 ◽  
pp. 1-11
Author(s):  
Greta G. Gramig ◽  
Samantha K. Hogstad ◽  
Patrick M. Carr
Keyword(s):  
Weed Management ◽  
Production Systems ◽  
Weed Suppression ◽  
Plastic Mulch ◽  
Yield Data ◽  
Weed Biomass ◽  
Soil Temperatures ◽  
The Impact ◽  
Hemp Hurd ◽  
Amended Soil

Abstract During 2015 and 2016, studies were conducted at Absaraka and Dickinson, North Dakota to evaluate the impacts of hemp (applied at 1156 m3 ha−1) and commercial paper mulch, as well as soil-applied biochar (applied at 11.25 m3 ha−1), on weed suppression and strawberry growth during the establishment year, and on weed suppression and strawberry yield during the production year, in a matted row production (MRP) system. During 2015, biochar influenced dry weed biomass only within the hemp mulch, with slightly more weed biomass associated with biochar application compared to zero biochar (3.1 vs 0.4 g m−2), suggesting that biochar may have increased weed germination and/or emergence from beneath hemp mulch. Biochar application also slightly increased soil pH, from 6.9 in non-amended soil to 7.0 in amended soil. Strawberry runner number during 2015 was greater in association with hemp or paper mulch compared to zero mulch (4.5 and 4.9 vs 2.4 runners plant −1, respectively). This result mirrored a similar differential in per berry mass across sites (7.6 and 7.4 vs 6.2 g berry −1 for hemp mulch, paper mulch and zero mulch, respectively). These results may be related to hemp and paper mulch reducing maximum soil temperatures during summer 2015. During the establishment year, both hemp and paper mulch suppressed weeds well compared to zero mulch, although at Absaraka hemp mulch provided slightly better weed suppression than paper mulch. During the production year, both mulches continued to suppress weeds compared to zero mulch at Dickinson. However, at Absaraka, only hemp mulch provided weed suppression compared to zero mulch, possibly because of faster paper degradation caused by greater numbers of large precipitation events and greater relative humidity at Absaraka compared to Dickinson. Weeds were removed from plots during 2015 to allow separation of weed suppression from other possible mulch impacts; therefore, yield data do not reveal striking differences among mulch treatments. Because previous research has demonstrated the impact of weed management during the establishment of strawberries in a matted row system, we concluded that hemp mulch may provide more durable weed suppression compared to paper mulch, which would increase strawberry yield protection in an MRP system. Material cost may be an issue for implementing hemp mulch, as hemp hurd cost was 25 times paper mulch at the application rates used in this study. However, hemp mulch could still be a beneficial option, especially for organic strawberry growers desiring a renewable and environmentally sound replacement for plastic mulch who are able to find affordable local sources of this material.

Impact of Spring Wheat Planting Density, Row Spacing, and Mechanical Weed Control on Yield, Grain Protein, and Economic Return in Maine

Weed Science ◽  
2012 ◽  
Vol 60 (2) ◽  
pp. 244-253 ◽  
Author(s):  
Lauren N. Kolb ◽  
Eric R. Gallandt ◽  
Ellen B. Mallory
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Weed Suppression ◽  
Planting Density ◽  
Grain Protein ◽  
Seeding Rate ◽  
Management Options ◽  
Weed Density ◽  
Net Returns ◽  
Farmer Practices

Effective in-season weed management options are limited for organic cereal farmers. Two alternatives to current farmer practices are improving efficacy of physical weed control through use of interrow cultivation or increasing the competitive ability of the crop through elevated seeding rates and more uniform spatial planting patterns. It is unknown how these two methods affect yield, quality, and economic returns. Field experiments were conducted in the northeast United States to determine whether the yield gain from increased weed control from these contrasting weed management strategies resulted in increased net returns and how these different systems affected grain quality. Wheat was planted at two seeding rates (400 and 600 plants m−2), in three row spacings (11, 18, and 23 cm). A fourth crop arrangement that approaches a more uniform spatial distribution through a combination of drilling and broadcasting seed was included. For weed control, treatments received tine harrowing. Wheat sown in wide rows also received interrow cultivation. Each system was sown in the presence and absence of condiment mustard, which was sown as a surrogate weed. Increased seeding rate reduced weed density 64% compared to a crop-free check and 30% compared to regional farmers' practices of 18-cm rows and 400 plants m−2. Increased seeding rates lowered grain protein 5% compared to standard seeding rates. Wide rows, in combination with interrow cultivation, reduced weed density 62%, increased yield 16%, and net returns 19% compared to regional organic practices. Significant increases in grain N were limited to weed-free plots. While increased seeding rates improved weed suppression, the high input cost of organic seed make this an unsatisfactory alternative to interrow cultivation and current farmer practices, as yield would need to be. 15 t ha−1higher at elevated density to offset the extra cost of seed.

Effect of fertiliser phosphorus and nitrogen on the concentrations of oil and protein in grain and the grain yield of canola (Brassica napus L.) grown in south-western Australia

2007 ◽  
Vol 47 (8) ◽  
pp. 984 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Western Australia ◽  
Field Experiments ◽  
Grain Production ◽  
Brassica Napus L ◽  
Single Superphosphate ◽  
P Deficiency ◽  
Soil P ◽  
Soil P Testing

The effect of fertiliser phosphorus (P) and nitrogen (N) on seed (grain) yield and concentration of oil and protein in grain of canola (oil-seed rape; Brassica napus L.) was measured in two field experiments undertaken at eight sites from 1993–2005 in south-western Australia, on soils deficient in P and N. Six rates of P (0–40 kg P/ha as single superphosphate) and four rates of N (0–138 kg N/ha as urea) were applied. Significant grain yield increases (responses) to applied P occurred in both experiments and these responses increased as rates of applied N increased. For grain production, the P × N interaction was significant in all eight years and locations of the two experiments. Application of P had no effect on concentration of oil and protein in grain. Application of N always decreased the concentration of oil and increased the concentration of protein in grain. For canola grain production in the region, responses to applied N always occur whereas responses to applied P are rare, but if soil P testing indicates likely P deficiency, both P and N fertiliser need to be applied.

scholarly journals Safety of Oilseed Rape Straw Mulch of Different Lengths to Rice and Its Suppressive Effects on Weeds

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 201
Author(s):  
Jinwen Zhu ◽  
Wen Liang ◽  
Siyu Yang ◽  
Huifu Wang ◽  
Chunhua Shi ◽  
...  
Keyword(s):  
Oilseed Rape ◽  
Weed Suppression ◽  
Brassica Napus L ◽  
Straw Mulch ◽  
Rape Straw ◽  
Preceding Crop ◽  
Cyperus Difformis ◽  
Direct Seeded ◽  
Environmentally Sound ◽  
The Impact

Rice is widely grown after harvesting of oilseed rape (Brassica napus L.) in many countries. Experiments were carried out under greenhouse and field conditions to assess the impact of oilseed rape straw mulch on rice and paddy weeds. Oilseed rape mulch (900 g m−2) from straw 1-to-7 cm long was found to be safe for rice, when applied four days after sowing (DAS) in direct-seeded rice or four days after transplanting (DAT). In the meantime, the biomass of Echinochloa crus-galli (L.) P. Beauv. was reduced 65.74%, 80.18%, 81.15%, 70.99%, 55.65%, and 27.22%, respectively, when mulched with powder, and 1, 3, 5, 7, and 9-cm long oilseed rape straw, respectively, and the biomass reductions in Leptochloa chinensis (L.) Nees., Ludwigia prostrata Roxb., Ammannia auriculata Willd., and Cyperus difformis L. were all above 97% when mulched with 1 cm-length straw. The results of a field trial confirmed that oilseed rape straw mulch (900 g m−2) of 1 cm length was safe for rice. Moreover, weed suppression was as effective as the standard herbicide (oxadiargyl + butachlor 525 g ai ha−1) treatment. These findings demonstrate the potential to manage paddy rice weeds in an effective and environmentally sound manner by mulching with the straw of a preceding crop, oilseed rape.

scholarly journals The Potentiality of Marine Macro-Algae as Bio-Fertilizers to Improve the Productivity and Salt Stress Tolerance of Canola (Brassica napus L.) Plants

Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 146 ◽  
Author(s):  
Hashem H.A. ◽  
Mansour H.A. ◽  
El-Khawas S.A. ◽  
Hassanein R.A.
Keyword(s):  
Salt Stress ◽  
Brassica Napus ◽  
Stress Tolerance ◽  
Growth And Yield ◽  
Phytochemical Analysis ◽  
Salt Stress Tolerance ◽  
Brassica Napus L ◽  
Indole Butyric Acid ◽  
Total Carbohydrates ◽  
The Impact

The present study aimed to evaluate the potentiality of three seaweeds, which belong to different algal taxa (green alga Ulva lactuca Linnaeus, brown alga Cystoseira spp., and red alga Gelidium crinale (Hare ex Turner) Gaillon) as bio-fertilizers to improve the growth and yield of canola (Brassica napus L.) plants under greenhouse conditions. Furthermore, the impact of seaweeds in alleviating the effects of salt stress (75 and 150 mM NaCl) on canola plants was also investigated. The three examined seaweeds (applied as soil amendments) successfully alleviated the harmful effects of salinity on canola plants by significantly reducing the inhibition of chlorophyll a, b, total carbohydrate accumulation, and growth promoting hormones, while increasing antioxidative compounds, such as phenols, flavonoids, anthocyanin, and osmoprotectants, including total carbohydrates and proline. Phytochemical analysis of the three examined seaweeds suggests that their stimulatory effect on growth and productivity under normal and salinity growth conditions may be linked to their constituents of a wide variety of growth promotive hormones, including indole acetic acid, indole butyric acid, gibberellic acid, cytokinins, total carbohydrates, and phenolic compounds. U. lactuca was found to be the best candidate to be used as a bio-fertilizer to improve canola growth, yield, and salt stress tolerance.

INFLUENCE OF IRRIGATION AND SEEDING RATES ON YIELD AND YIELD COMPONENTS OF BRASSICA NAPUS CV. TOWER

1978 ◽  
Vol 58 (3) ◽  
pp. 731-737 ◽  
Author(s):  
J. M. CLARKE ◽  
G. M. SIMPSON
Keyword(s):  
Brassica Napus ◽  
Yield Components ◽  
Seed Weight ◽  
Plant Morphology ◽  
Yield Component ◽  
Seeding Rate ◽  
Brassica Napus L ◽  
Relationship Of ◽  
The Relationship ◽  
Number Of Seeds

An analysis of the yield components of rape (Brassica napus L.) was carried out under field conditions for 2 yr at Saskatoon. Plant morphology and the crop environment were altered by the use of four planting densities and three water regimes. The number of branches per plant was scarcely affected by irrigation, but was reduced by high seeding rates. Number of pods per plant was increased by irrigation and reduced by high seeding rates. The number of seeds per pod was increased by irrigation, but reduced by high seeding rates. The 1,000-seed weight was increased both by irrigation and increased seeding rate, as was seed yield. Yield was positively correlated with 1,000-seed weight in both years. Yield component compensation was evident in the relationship of 1,000-seed weight to pod number and number of seeds per pod.

Screening rhizobacteria for improving the growth, yield, and oil content of canola (Brassica napus L.)

2004 ◽  
Vol 55 (2) ◽  
pp. 187 ◽  
Author(s):  
H. N. Asghar ◽  
Z. A. Zahir ◽  
M. Arshad
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Root Length ◽  
Oil Content ◽  
Growth Promotion ◽  
Brassica Napus L ◽  
Growth Promoting ◽  
1000 Grain Weight ◽  
Number Of Branches

One hundred rhizobacteria previously isolated from the rhizospheres of Brassica species were screened for their growth promoting activity in Brassica napus L. under gnotobiotic conditions. Results revealed that 58% of the rhizobacteria increased root length (up to 139%), 39% enhanced shoot length (up to 78%), and shoot weight (up to 72%) of Brassica napus L. Based upon growth promotion of B. napus seedlings under gnotobiotic conditions, 10 promising plant-growth-promoting rhizobacteria (PGPR) were selected and tested for their effectiveness in growth promotion, yield, and oil content of B. napus grown in pots. The pot trials revealed that inoculation with selected PGPR increased plant height, root length, number of branches per plant, stem diameter, number of pods per plant, 1000-grain weight, grain yield, and oil content over a range of 7–57% above the uninoculated control. These isolates were then assayed for their ability to produce auxins in vitro in the presence and absence of L-tryptophan. Regression analysis showed that in vitro auxin production by these bacteria was significantly related to the number of branches and oil content of B. napus. It is highly likely that improvement in growth and yield of the inoculated plants is due to an increase in the number of branches per plant, since there was a positive correlation of this growth parameter with the number of pods per plant, 1000-grain weight, grain yield, and seed oil content. Results indicated that simultaneous screening of rhizobacteria for growth promotion under gnotobiotic conditions and in vitro production of auxins could be a useful approach for selecting effective PGPR.

EFFECT OF ROW SPACING AND SEEDING RATES ON SUMMER RAPE IN SOUTHERN MANITOBA

1990 ◽  
Vol 70 (1) ◽  
pp. 127-137 ◽  
Author(s):  
M. J. MORRISON ◽  
P. B. E. McVETTY ◽  
R. SCARTH
Keyword(s):  
Brassica Napus ◽  
Seed Quality ◽  
Plant Density ◽  
Chlorophyll Concentration ◽  
Plant Distribution ◽  
Row Spacing ◽  
Seeding Rate ◽  
Brassica Napus L ◽  
Plant Densities ◽  
Lower Plant

To determine the effects of varying plant densities on summer rape (Brassica napus L.), the cultivar Westar was seeded in 15- and 30-cm row spacings at seeding rates of 1.5, 3.0, 6.0, and 12.0 kg ha−1. Plants seeded in 15-cm rows yielded more per area, produced more pods per plant and lodged less than those in 30-cm rows. Higher yields were associated with a more even plant distribution and a lower degree of intra-row competition. There were no significant protein, oil and chlorophyll concentration differences between the row spacing treatments. The highest yields (kg ha−1) were achieved with the 1.5 and 3.0 kg ha−1 seeding rates. Summer rape compensated for lower plant densities with the production of more branch racemes. As seeding rate increased, competitive mortality increased, resulting in greater etiolation at bolting, and greater lodging at harvest. Seed oil and protein concentrations were not affected by seeding rate. However, seed chlorophyll concentration decreased with increased seeding rate.Key words: Brassica napus, plant density, seed quality, rape (summer)

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