Impact of growing conditions on the competitive ability of Camelina sativa (L.) Crantz (Camelina)

Davis, P. B., Maxwell, B. and Menalled, F. D. 2013. Impact of growing conditions on the competitive ability of Camelina sativa (L.) Crantz (Camelina). Can. J. Plant Sci. 93: 243–247. It has been claimed that Camelina sativa, a recently introduced crop in the northern Great Plains, is a highly competitive species. However, this issue has not been formally tested. Utilizing replacement series diagrams, we assessed the importance of growing conditions in the competitive ability of C. sativa. Results indicated that canola and Bromus tectorum were superior competitors in both loam and sandy soils, thus providing evidence that C. sativa may not be as competitive as previously indicated.

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The use of nitrogen, phosphorus and lime to limit the competitive ability of Aristida armata in the establishment phase

Australian Journal of Agricultural Research ◽

10.1071/ar9930165 ◽

1993 ◽

Vol 44 (1) ◽

pp. 165 ◽

Cited By ~ 7

Author(s):

RD Armstrong ◽

RF Brown ◽

KR Helyar

Keyword(s):

Competitive Advantage ◽

Competitive Ability ◽

Cenchrus Ciliaris ◽

Replacement Series ◽

Red Earth ◽

Competitive Species ◽

Per Se ◽

Grazing Lands ◽

Establishment Phase ◽

Nitrogen Phosphorus

The de Wit replacement series methodology was used to see if applying phosphorus, nitrogen and lime to the sandy red earth soils of mulga grazing lands can give a competitive advantage to the desirable species Cenchrus ciliaris C.V. U.S.A., Digitaria ammophila, and Thyridolepis mitchelliana over the less desirable Aristida armata. In monoculture, all species responded strongly to added nutrients, especially phosphorus. In mixtures, the preferred grasses responded even more strongly to nutrients, whereas A. armata responsed proportionally less. C. ciliaris, D. ammophila, and T. mitchelliana suppressed the growth of A. amnata in all but three situations: without added nutrients, A. armata was equally competitive with C. ciliaris; when P was added without lime, A. armata suppressed C. ciliaris; if P was added without N, A. armata suppressed T. mitchelliana. Adding either or both nitrogen or phosphorus usually increased the relative crowding coefficients, indicating that the degree of suppression of Aristida was increased by adding nutrients. Thus, C. ciliaris, D. ammophila, and T. mitchelliana appear to be equally competitive with or more competitive than A. armata if the soil is not fertilized and adding nutrients generally enhances this competitiveness. In all cases, except for A. armata/C ciliaris mixtures in soils low in phosphorus, the plants appeared to be competing for the same resource. The study demonstrated that A. armata is not a highly competitive species per se under controlled conditions and was generally suppressed by the preferred grasses, especially when nutrients were added.

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Cultural weed management practices shorten the critical weed-free period for soybean grown in the Northern Great Plains

Weed Science ◽

10.1017/wsc.2019.60 ◽

2019 ◽

pp. 1-13

Author(s):

Jonathan D. Rosset ◽

Robert H. Gulden

Keyword(s):

Great Plains ◽

Weed Management ◽

Competitive Ability ◽

Management Practices ◽

Developmental Stages ◽

Cultural Practices ◽

Northern Great Plains ◽

Herbicide Resistant ◽

Soybean Cultivars ◽

Rotational Crop

Abstract Soybean [Glycine max (L.) Merr.] has recently become a popular rotational crop in the Canadian Northern Great Plains where herbicide-resistant (HR) soybean cultivars have been widely adopted. Intense reliance on herbicides has contributed to the development of HR weeds in soybean and other crops. Cultural weed management practices reduce the need for herbicides and lower the selection pressure for HR weed biotypes by improving the competitiveness of the crop. The effects of two row spacings, three target densities, and three cultivars on the critical weed-free period (CWFP) in soybean were evaluated as three separate experiments in southern Manitoba. In the row-spacing experiment, soybean grown in narrow rows shortened the CWFP by up to three soybean developmental stages at site-years with increased weed pressure. In the target density experiment, low-density soybean stands lengthened the CWFP by one soybean developmental stage compared with higher-density soybean stands. The effect of soybean cultivar varied among locations, yet tended to be consistent within location over the 2-yr study, suggesting that competitive ability in these soybean cultivars was linked to edaphic and/or environmental factors. Generally, the cultivar with the shortest days to maturity, which also had the shortest stature, consistently had a longer CWFP. Each of these cultural practices were effective at reducing the need for in-crop herbicide applications.

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Weed-Competitive Ability of Spring and Winter Cereals in the Northern Great Plains

Weed Technology ◽

10.1614/wt-d-09-00036.1 ◽

2010 ◽

Vol 24 (2) ◽

pp. 108-116 ◽

Cited By ~ 49

Author(s):

Brian L. Beres ◽

K. Neil Harker ◽

George W. Clayton ◽

Eric Bremer ◽

Robert E. Blackshaw ◽

...

Keyword(s):

Great Plains ◽

Competitive Ability ◽

Spring Barley ◽

Weed Suppression ◽

Northern Great Plains ◽

Grain Yields ◽

Ecological Zones ◽

Winter Cereals ◽

Plant Densities ◽

Spring Cereals

The inclusion of winter cereals in spring-annual rotations in the northern Great Plains may reduce weed populations and herbicide requirements. A broad range of spring and winter cereals were compared for ability to suppress weeds and maximize grain yield at Lacombe (2002 to 2005) and Lethbridge (2003 to 2005), Alberta, Canada. High seeding rates (≥ 400 seeds/m2) were used in all years to maximize crop competitive ability. Spring cereals achieved high crop-plant densities (> 250 plants/m2) at most sites, but winter cereals had lower plant densities due to winterkill, particularly at Lethbridge in 2004. All winter cereals and spring barley were highly effective at reducing weed biomass at Lacombe for the first 3 yr of the study. Weed suppression was less consistently affected by winter cereals in the last year at Lacombe and at Lethbridge, primarily due to poor winter survival. Grain yields were highest for spring triticale and least for spring wheat at Lacombe, with winter cereals intermediate. At Lethbridge, winter cereals had higher grain yields in 2003 whereas spring cereals had higher yields in 2004 and 2005. Winter cereals were generally more effective at suppressing weed growth than spring cereals if a good crop stand was established, but overlap in weed-competitive ability among cultivars was considerable. This information will be used to enhance the sustainable production of winter and spring cereals in traditional and nontraditional agro-ecological zones.

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Biennial wormwood (Artemisia biennis) competition with soybean (Glycine max)

Phytoprotection ◽

10.7202/012512ar ◽

2006 ◽

Vol 86 (2) ◽

pp. 125-132 ◽

Cited By ~ 3

Author(s):

Eric A. Nelson ◽

George O. Kegode

Keyword(s):

United States ◽

Great Plains ◽

Negative Impact ◽

Relative Yield ◽

The United States ◽

Northern Great Plains ◽

Fresh Weight ◽

Replacement Series ◽

Nitrogen Rate ◽

Nitrogen Fertility

Biennial wormwood has become a serious weed of several crops in the northern Great Plains of the United States and Prairie Provinces of Canada. Greenhouse replacement series experiments were conducted to investigate the effects of watering regime (stressed and non-stressed) and nitrogen rate (50, 100, 150, and 200 mg kg-1 of soil) on competition between soybean and biennial wormwood. Soybean height was reduced after 9 weeks of competition with biennial wormwood compared with soybean grown in monoculture, whereas biennial wormwood plants were taller when grown with soybean than in monoculture. The change in plant height indicated that biennial wormwood height was increased due to interspecific competition, whereas soybean height was reduced. When moisture was limited, the relative yield of biennial wormwood was greater than that of soybean, indicating that biennial wormwood was more aggressive than soybean. Soybean growth was unaffected by an increase in nitrogen rate, whereas biennial wormwood fresh weight was 30% greater when the nitrogen rate was increased from 50 to 200 mg kg-1. Biennial wormwood aggressivity tended to increase as the nitrogen rate was increased from 50 to 200 mg kg-1. Overall results suggest that the negative impact of biennial wormwood competition with soybeans under field conditions may increase when soil moisture is limited and nitrogen fertility is increased.

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