2 results
Weed suppression by Medicago sativa in subsequent cereal crops: a comparative survey
- P. D. Ominski, M. H. Entz, N. Kenkel
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- Journal:
- Weed Science / Volume 47 / Issue 3 / June 1999
- Published online by Cambridge University Press:
- 12 June 2017, pp. 282-290
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The ability of Medicago sativa to suppress weed growth may provide a viable alternative to chemical weed control and allow crop producers to reduce herbicide inputs. Quantitative information regarding the suppressive effect of M. sativa on weed populations in current cropping systems is lacking. A survey was conducted in Manitoba, Canada, in 1993 and 1994 to investigate weed populations in commercial cereal fields that had been preceded by either M. sativa hay or cereal grain crops. A total of 117 fields were surveyed; approximately half from each field type. Principle component analysis indicated that the inclusion of M. sativa in crop rotations resulted in weed communities different from those of continuous cereal fields. Naturally occurring populations of Avena fatua, Cirsium arvense, Brassica kaber, and Galium aparine were lower in cereal fields that had previously contained M. sativa than in cereal fields that had been preceded by a cereal crop. Lower field uniformity values for C. arvense and Avena fatua indicated that these weeds were also more patchy in the M. sativa rotations. Population differences between field types were nonsignificant for Amaranthus retroflexus, Chenopodium album, and Polygonum convolvulus, and although populations of Taraxacum officinale and Thlaspi arvense were greater in M. sativa/cereal fields than in continuous cereal crops. No consistent effect of field type on Setaria viridis populations was observed. These results show that M. sativa effectively suppressed some, but not all, of the weeds found in the study area. Including M. sativa hay crops in crop rotations can be part of an integrated weed management strategy for weeds such as A. fatua, B. kaber, and C. arvense.
Pesticide Free Production: Characteristics of farms and farmers participating in a pesticide use reduction pilot project in Manitoba, Canada
- Orla M. Nazarko, Rene C. Van Acker, Martin H. Entz, Allison Schoofs, Gary Martens
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- Journal:
- Renewable Agriculture and Food Systems / Volume 19 / Issue 1 / March 2004
- Published online by Cambridge University Press:
- 12 February 2007, pp. 4-14
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Strategies for pesticide use reduction have suffered from limited adoption. The impact of such strategies will be greater if they appeal to farmers with typical demographics and attitudes. A participatory, on-farm study was conducted to assess the potential of Pesticide Free ProductionTM (PFP) [Pesticide Free ProductionTM and PFPTM are registered trademarks of the University of Manitoba.] to be widely implemented on mainstream farms in Manitoba, Canada. PFP is a flexible, simple framework intended to appeal broadly to farmers who may not have adopted other pesticide use reduction initiatives. It may also provide a marketable food product label. This novel crop production system prohibits the use of in-crop pesticides and seed treatments during one crop year, as well as prior use of residual pesticides. Applications of nonresidual pesticides (such as glyphosate) are permitted prior to crop emergence. Synthetic fertilizer use is permitted at any time. The objectives of this study were: (1) to determine if the demographic and attitudinal characteristics of farms and farmers participating in a PFP pilot project varied depending on the level of PFP implementation; and (2) to compare the characteristics of farms and farmers participating in the pilot project with standards representing average farms and farmers in Manitoba. A total of 71 farmers, representing 120 fields and 11 crops, participated in the study. Fields and farmers were categorized into three groups, based on whether or not fields: (1) achieved PFP certification status and (2) were in transition to organic production. There were few demographic differences among groups. Demographic characteristics of participating farmers were typical for Manitoba, with the exception that participating farmers who were not in transition to organic production had higher levels of education than a random sample of Manitoba farmers. Attitudinal orientation (adherence to a conventional versus an alternative agricultural paradigm) of participants who were not in transition to organic production was similar to that of a random sample of Manitoba farmers. Fields and farms on which PFP was implemented were relatively large in the context of Manitoba averages. Participants indicated high satisfaction with certifiable PFP crops and high levels of interest in implementing future PFP. Pesticide free production demonstrates significant potential for broad adoption in this region.