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Integrating physical and cultural methods of weed control— examples from European research

Published online by Cambridge University Press:  20 January 2017

Bo Melander ,
Ilse A. Rasmussen  and
Paolo Bàrberi
Ilse A. Rasmussen
Affiliation:
Danish Institute of Agricultural Sciences, Department of Integrated Pest Management, Research Centre Flakkebjerg, DK-4200 Slagelse, Denmark
Paolo Bàrberi
Affiliation:
Land Lab, Scuola Superiore Sant'Anna, Piazza Martiri della Libertà 33, I-56127 Pisa, Italy
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Abstract

Increasing concerns about pesticide use and a steadily increasing conversion to organic farming have been major factors driving research in physical and cultural weed control methods in Europe. This article reviews some of the major results achieved with nonchemical methods and strategies, especially adapted for row crops (e.g., corn, sugar beet, onion, leek, and carrot) and small-grain cereals (e.g., barley and wheat). In row crops, intrarow weeds constitute a major challenge, and research has mainly aimed at replacing laborious hand-weeding with mechanization. A number of investigations have focused on optimizing the use of thermal and mechanical weeding methods against intrarow weeds, such as flaming, harrowing, brush weeding, hoeing, torsion weeding, and finger weeding. And new methods are now under investigation such as robotic weeding for row crops with abundant spacing between individual plants and band-steaming for row crops developing dense crop stands. The strategic use of mechanical weed control methods in small-grain cereals has been another area of considerable interest. Weed harrowing and interrow hoeing provide promising results when they are part of a strategy that also involves cultural methods such as fertilizer placement, seed vigor, seed rate, and competitive varieties. Although research in preventive, cultural, and physical methods have improved weed control in row crops and small-grain cereals, effective long-term weed management in low external input and organic systems can only be achieved by tackling the problem in a wider context, i.e., at the cropping system level. Basic principles of this approach, examples of cover crop and intercropping use for weed suppression, and an application in a 2-yr rotation are presented and discussed.

Keywords

Barley, Hordeum vulgare L.carrot, Daucus carota L.corn, Zea mays L.leek, Allium porrum L.onion, Allium cepa L.sugar beet, Beta vulgaris L.wheat, Triticum aestivum L.Mechanical weed controlthermal weed controlpreventive methodsorganic croppinglow-input systems
Type
Symposium
Information
Weed Science , Volume 53 , Issue 3 , June 2005 , pp. 369 - 381
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Andersson, B. 1983. Odlingstekniska försök med höstvete: verkan av såtid, utsädesmängd, radavstånd, kvävegödsling och skördetid i kombination med olika sorter. (Studies on cultivation technique of winter wheat: influence of sowing time, seed rate, row space, nitrogen fertilization and harvest time combined with different cultivars. With English summary). Uppsala, Sweden: Institutionen for växtodling. Rapport 1, Swedish University of Agricultural Sciences. Pp. 1–63.Google Scholar
Andrews, R. W., Peters, S. E., Janke, R. R., and Sahs, W. W. 1990. Converting to sustainable farming systems. Pages 281–313 in Francis, C. A., Flora, C. B., and King, L. D. eds. Sustainable Agriculture in Temperate Zones. New York: J. Wiley.Google Scholar
Angelini, L., Lazzeri, L., Galletti, S., Cozzani, A., Macchia, M., and Palmieri, S. 1998. Antigerminative activity of three glucosinolate-derived products generated by mirosinase hydrolysis. Seed Sci. Technol 26:771–780.Google Scholar
Ascard, J. 1990. Weed control in ecological vegetable farming. Pages 178–184 in Proceedings of the Ecological Agriculture, Nordiske Jordbrugsforskeres Forening, Scandinavia, Seminar 166.Google Scholar
Ascard, J. 1994a. Dose–response models for flame weeding in relation to plant size and density. Weed Res 34:377–385.CrossRefGoogle Scholar
Ascard, J. 1994b. Soil cultivation in darkness reduced weed emergence. Acta Hortic 372:167–177.Google Scholar
Ascard, J. 1995. Effects of flame weeding on weed species at different developmental stages. Weed Res 35:397–411.CrossRefGoogle Scholar
Ascard, J. 1998. Comparison of flaming and infrared radiation techniques for thermal weed control. Weed Res 38:69–76.CrossRefGoogle Scholar
Ascard, J. and Bellinder, M. 1996. Mechanical in-row cultivation in row crops. Pages 1121–1126 in Proceedings Second International Weed Control Congress. Copenhagen, Denmark: International Weed Science Society.Google Scholar
Ascard, J., Hallefält, F., and Olsson, R. 1995a. System för ogräsbekämpning i sockerbetor. Chapter 21. Pages 1–11 in Försöksverksamhet i Sockerbetor 1995. Arlöv, Sweden: SockerNäringens SamarbeitsKommitté.Google Scholar
Ascard, J., Hallefält, F., and Olsson, R. 1995b. Mekanisk ogräsbekämpning i raden med olika redskap. Chapter 26. Pages 1–8. in Försöksverksamhet i Sockerbetor 1995. Arlöv, Sweden: SockerNäringens SamarbeitsKommitté.Google Scholar
Balsari, P., Berruto, R., and Ferrero, A. 1994. Flame weed control in lettuce crops. Pages 213–222 in Holmoy, R., Redalen, N., Redalen, G., Henriksen, K., and Hagenvall, H. eds. Acta Horticulturae 372, Engineering for Reducing Pesticide Consumption & Operator Hazards.Google Scholar
Bàrberi, P. 2002. Weed management in organic agriculture: are we addressing the right issues? Weed Res 42:176–193.Google Scholar
Bàrberi, P. and Mazzoncini, M. 2001. Changes in weed community composition as influenced by cover crop and management system in continuous corn. Weed Sci 49:491–499.Google Scholar
Bàrberi, P., Silvestri, N., Peruzzi, A., and Raffaelli, M. 2000. Finger harrowing of durum wheat under different tillage systems. Biol. Agric. Hortic 17:285–303.Google Scholar
Bastiaans, L. and Drenth, H. 1999. Late-emerging weeds; phenotypic plasticity and contribution to weed population growth. Page 3 in Proceedings of the 11th EWRS Symposium, June 28–July 1, Basel, Switzerland. Doorwerth, The Netherlands: European Weed Research Society.Google Scholar
Baumann, D. 1992. Mechanical weed control with spring tine harrows (weed harrows) in row crops. Pages 123–128 in Proceedings IXth International Symposium on the Biology of Weeds. Dijon, France: Association Nationale pour la Protection des Plantes.Google Scholar
Baumann, D. T., Kropff, M. J., and Bastiaans, L. 2000. Intercropping leeks to suppress weeds. Weed Res 40:359–374.Google Scholar
Baumann, D. T., Potter, C. A., and Müller-Schärer, H. 1993. Zeitbezogene Schadensschwellen bei der Integrierten Unkrautbekämpfung im Freilandgemüsebau. (Critical periods of weed competition in outdoor vegetables. With English summary). Pages 807–813 in Proceedings 8th EWRS Symposium, Quantitative Approaches in Weed and Herbicide Research and Their Practical Application, Braunschweig, Germany. Doorwerth, The Netherlands: European Weed Research Society.Google Scholar
Becker, K. and Böhrnsen, A. 1994. Wirkungen mechanischer Pflegemaßnahmen auf die Unkrautabundanz und die N-mineralisation im Boden. Z. Pflanzenkr. Pflanzenschutz 14:315–324. [In German with English Abstract].Google Scholar
Bertram, A. 1994. Wärmeübergang und Pflanzenschädigung bei der thermischen Unkrautbekämpfung. (Heat transfer and plant damages in thermal weed control. With English summary). Z. Pflanzenkr. Pflanzenschutz. Sonderheft 14:273–280.Google Scholar
Blair, A. M. and Green, M. R. 1993. Integrating chemical and mechanical weed control to reduce herbicide use. Pages 985–990 in Proceedings 1993 Brighton Crop Protection Conference—Weeds. Brighton, U.K.: British Crop Protection Council.Google Scholar
Blair, A. M., Jones, P. A., Orson, J. H., and Caseley, J. C. 1997. Integration of row widths, chemical and mechanical weed control and the effect on winter wheat yield. Asp. Appl. Biol 50:385–392.Google Scholar
Blasco, J., Aleixos, N., Roger, J. M., Rabatel, G., and Molto, E. 2002. Robotic weed control using machine vision. Biosyst. Eng 83:149–157.Google Scholar
Bond, W. and Baker, P. J. 1990. Patterns of weed emergence following soil cultivation and its implications for weed control in vegetable crops. Pages 63–68 in Unwin, R. ed. Organic and Low Input Agriculture. British Crop Protection Council Monograph 45. Bracknell, U.K.: British Crop Protection Council.Google Scholar
Bond, W. and Grundy, A. C. 2001. Non-chemical weed management in organic farming systems. Weed Res 41:383–405.CrossRefGoogle Scholar
Bontsema, J., van Asselt, C. J., Lempens, P. W. J., and van Straten, G. 1998. Intra-row weed control: a mechatronics approach. Pages 93–97 in Sigrimis, N. and Groubos, P. eds. Proceedings 1st IFAC Workshop. Control Applications and Ergonomics in Agriculture. Athens, Greece: International Federation of Automatic Control.Google Scholar
Bowman, G. 1997. Steel in the Field: A Farmer's Guide to Weed Management Tools. Burlington, VT: Sustainable Agriculture Publications, University of Vermont. 128 p.Google Scholar
Boydston, R. A., Al-Khatib, K., Vaughn, S. F., Collins, H. P., and Alva, A. K. 2004. Weed suppression using cover crops and seed meals. Page 16 in Proceedings of the 1st International Symposium “Biofumigation: A Possible Alternative to Methyl Bromide?”, March 31–April 1. Firenze, Italy: Research Institute for Industrial Crops of the Italian Ministry of Agricultural and Forestry Policies.Google Scholar
Brandsæter, L. O. and Netland, J. 1999. Winter annual legumes for use as cover crops in row crops in Northern regions: I. Field experiments. Crop Sci 39:1369–1379.Google Scholar
Brown, J., Hamilton, M., and Brown, D. A. 2004. Using brassicaceae seed meal as an alternative to highly toxic soil fumigants in strawberry production. Pages 14–15 in Proceedings of the 1st International Symposium “Biofumigation: A Possible Alternative to Methyl Bromide?”, March 31–April 1. Firenze, Italy: Research Institute for Industrial Crops of the Italian Ministry of Agricultural and Forestry Policies.Google Scholar
Buhler, D. D. 1999. Expanding the context of weed management. Pages 1–7 in Expanding the Context of Weed Management. New York: Haworth.Google Scholar
Buhler, D. D., Gunsolus, J. L., and Ralston, D. F. 1992. Integrated weed management techniques to reduce herbicide inputs in soybean. Agron. J 84:973–978.Google Scholar
Bulson, H. A. J., Snaydon, R. W., and Stopes, C. E. 1990. Intercropping autumn-sown beans and wheat: effects on weeds under organic farming conditions. Pages 55–62 in Unwin, R. ed. Crop Protection in Organic and Low Input Agriculture. British Crop Protection Council Monograph 45. Bracknell, U.K.: British Crop Protection Council.Google Scholar
Christensen, S., Rasmussen, G., and Olesen, J. E. 1994. Differential weed suppression and weed control in winter wheat. Asp. Appl. Biol 2:335–342.Google Scholar
Christensen, S., Rasmussen, G., Olesen, J. E., and Jørgensen, L. N. 1996. Weed management for integrated winter wheat production. Pages 1003–1008 in Proceedings Second International Weed Control Congress. Copenhagen, Denmark: International Weed Science Society.Google Scholar
Cirujeda, A., Melander, B., Rasmussen, K., and Rasmussen, I. A. 2003a. Relationship between speed, soil movement into the cereal row and intra-row weed control efficacy by weed harrowing. Weed Res 43:285–296.Google Scholar
Cirujeda, A., Recasens, J., and Taberner, A. 2003b. Effect of ploughing and harrowing on a herbicide resistant corn poppy (Papaver rhoeas) population. Biol. Agric. Hortic 21:231–246.Google Scholar
Didon, U. M. E. 2002. Variation between barley cultivars in early response to weed competition. J. Agron. Crop Sci 188:176–184.Google Scholar
Ellwanger, T. C., Bingham, S. W., and Chappell, W. E. 1973a. Physiological effects of ultra-high temperatures on corn. Weed Sci 21:296–299.Google Scholar
Ellwanger, T. C., Bingham, S. W., Chappell, W. E., and Tolin, S. A. 1973b. Cytological effects of ultra-high temperatures on corn. Weed Sci 21:299–303.Google Scholar
Fogelberg, F. 1999. Night-time soil cultivation and intra-row brush weeding for weed control in carrots (Daucus carota L). Biol. Agric. Hortic 17:31–45.Google Scholar
Grundy, A. C. and Froud-Williams, R. J. 1997. The control of weeds in cereals using an integrated approach. Asp. Appl. Biol 50:367–374.Google Scholar
Grundy, A. C., Green, J. M., and Lennartsson, M. 1998. The effect of temperature on the viability of weed seeds in compost. Compost Sci. Util 6:26–33.Google Scholar
Hall, W., Brandsæter, L. O., Breland, T. A., and Meadow, R. 2004. Cover crops in cauliflower production: implications for weeds, insects, beneficial arthropods and yield. Page 166 in Proceedings of the 6th Workshop of the EWRS Working Group on Physical and Cultural Weed Control, March 8–10, Øyer, Norway. www.ewrs.org/pwc/archive.htm.Google Scholar
Hansen, P. K. 2002. A method to index competitiveness against weeds of spring barley varieties. Pages 296–297 in Proceedings of the 12th EWRS Symposium Wageningen 2002, Papendal, The Netherlands. European Weed Research Society.Google Scholar
Haymes, R. and Lee, H. C. 1999. Competition between autumn and spring planted grain intercrops of wheat (Triticum aestivum) and field bean (Vicia faba). Field Crops Res 62:167–176.CrossRefGoogle Scholar
Ikerd, J. E. 1993. The need for a system approach to sustainable agriculture. Agric. Ecosyst. Environ 46:147–160.Google Scholar
Jensen, P. K. 1992. First Danish experiences with photocontrol of weeds. Z. Pflanzenkr. Pflanzenschutz. Sonderheft XIII:631–636.Google Scholar
Jensen, P. K. 1995. Effect of light environment during soil disturbance on germination and emergence pattern of weeds. Ann. Appl. Biol 127:561–571.Google Scholar
Johansson, D. 1998. Radhackning med och utan efterredskap i stråsäd. (Row hoeing in cereals with and without tools behind. Final report for field experiments 1995–1997. With English summary). Uppsala, Sweden: Sveriges Lantbruksuniversitet, Rapporter från jordbearbetningsavdelingen no. 94. 55 p.Google Scholar
Johnson, W. C. and Mullinix, B. G. 1995. Weed management in peanut using stale seedbed techniques. Weed Sci 43:293–297.Google Scholar
Kees, H. 1962. Untersuchungen zur Unkrautbekämpfung durch Netzegge und Stoppelbearbeitungsmassnahmen. Ph.D. dissertation, Universität Stuttgart-Hohenheim, Hohenheim, Germany. 102 p.Google Scholar
Kirkegaard, J. and Matthiessen, J. 2004. Developing and refining the biofumigation concept. Pages 2–3 in Proceedings of the 1st International Symposium “Biofumigation: A Possible Alternative to Methyl Bromide?”, March 31–April 1. Firenze, Italy: Research Institute for Industrial Crops of the Italian Ministry of Agricultural and Forestry Policies.Google Scholar
Kurstjens, D. A. G. and Bleeker, P. 2000. Optimising torsion weeders and finger weeders. Pages 30–32 in Proceedings of the 4th Workshop of the EWRS Working Group on Physical and Cultural Weed Control, March 20–22, Elspeet, The Netherlands, www.ewrs.org/pwc/archive.htm.Google Scholar
Kurstjens, D. A. G. and Kropff, M. J. 2001. The impact of uprooting and soil-covering on the effectiveness of weed harrowing. Weed Res 41:211–228.CrossRefGoogle Scholar
Kurstjens, D. A. G. and Perdok, U. D. 2000. The selective soil covering mechanism of weed harrows on sandy soil. Soil Tillage Res 55:193–206.Google Scholar
Kurstjens, D. A. G., Perdok, U. D., and Goense, D. 2000. Selective uprooting by weed harrowing on sandy soils. Weed Res 40:431–447.Google Scholar
Lagu&euml, C., Gill, J., and Péloquin, G. 2001. Thermal control in plant protection. Pages 35–46 in Fleurat-Lessard, F., Panneton, B., and Vincent, C. eds. Physical Control Methods in Plant Protection. Berlin, Germany: Springer-Verlag.Google Scholar
Lamers, J. G., Wanten, P., and Blok, W. J. 2004. Biological soil disinfestation: a different way of biofumigation to control soil borne pests and diseases. Page 17 in Proceedings of the 1st International Symposium “Biofumigation: A Possible Alternative to Methyl Bromide?”, March 31–April 1. Firenze, Italy: Research Institute for Industrial Crops of the Italian Ministry of Agricultural and Forestry Policies.Google Scholar
Lampkin, N. 1997. Weed management. Pages 161–213 in Lampkin, N. ed. Organic Farming. Ipswich, U.K.: Farming.Google Scholar
Leblanc, M. L. and Cloutier, D. C. 1996. Effect of the stale seedbed technique on annual weed emergence in maize. Pages 29–34 in Proceedings Xth International Symposium on the Biology of Weeds. Dijon, France: Association Nationale pour la Protection des Plantes.Google Scholar
Liebman, M. and Davis, A. S. 2000. Integration of soil, crop, and weed management in low-external-input farming systems. Weed Res 40:27–47.Google Scholar
Liebman, M. and Dyck, E. 1993. Crop rotation and intercropping strategies for weed management. Ecol. Appl 3:92–122.Google Scholar
Lockeretz, W. 2000. Organic farming research, today and tomorrow. Pages 718–720 in Proceedings of the 13th International IFOAM Scientific Conference, August 28–31. Basel, Switzerland: International Federation of Organic Agriculture Movements.Google Scholar
Lötjönen, T. and Mikkola, H. 2000. Three mechanical weed control techniques in spring cereals. Agric. Food Sci. Finl 9:269–278.Google Scholar
Lotz, L. A. P., van der Weide, R. Y., Horeman, G. H., and Joosten, L. T. A. 2002. Weed management and policies: from prevention and precision technology to certification of individual farms. Pages 2–3 in Proceedings of the 12th EWRS Symposium Wageningen 2002, Papendal, The Netherlands. European Weed Research Society.Google Scholar
Marshall, E. J. P., Brown, V. K., Boatman, N. D., Lutman, P. J. W., Squire, G. R., and War, L. K. 2003. The role of weeds in supporting biological diversity within crop fields. Weed Res 43:77–89.Google Scholar
Matthiessen, J. 2004. The importance of plant maceration and water in achieving high ITC levels in soil. Page 12 in Proceedings of the 1st International Symposium “Biofumigation: A Possible Alternative to Methyl Bromide?”, March 31–April 1. Firenze, Italy: Research Institute for Industrial Crops of the Italian Ministry of Agricultural and Forestry Policies.Google Scholar
Mattsson, B., Nylander, C., and Ascard, J. 1990. Comparison of seven inter-row weeders. Veröff. Bundesanst. Agrarbiol. Linz/Donau 20:91–107.Google Scholar
McCloskey, M., Firbank, L. G., Watkinson, A. R., and Webb, D. J. 1996. The dynamics of experimental arable weed communities under different management practices. J. Veg. Sci 7:799–808.Google Scholar
Melander, B. 1997. Optimization of the adjustment of a vertical axis rotary brush weeder for intra-row weed control in row crops. J. Agric. Eng. Res 68:39–50.Google Scholar
Melander, B. 1998a. Interactions between soil cultivation in darkness, flaming, and brush weeding when used for in-row weed control in vegetables. Biol. Hortic. Agric 16:1–14.CrossRefGoogle Scholar
Melander, B. 1998b. Economic aspects of physical intra-row weed control in seeded onions. Pages 180–185 in Proceedings 12th International IFOAM Scientific Conference. Mar del Plata, Argentina: International Federation of Organic Agriculture Movements.Google Scholar
Melander, B. 1998c. Anvendelse af falsk såbed, blindharvning og flammebehandling i højværdiafgrøder. (Pre-emergence weed control in crops of high value by means of a false seedbed technique, weed harrowing, and flaming. With English summary). Pages 191–201 in Proceedings 15th Danish Plant Protection Conference/Weeds. Nyborg, Denmark: Danish Institute of Agricultural Sciences.Google Scholar
Melander, B. 2000. Mechanical weed control in transplanted sugar beet. Page 24 in Proceedings of the 4th EWRS Workshop on Physical Weed Control, March 20–22, Elspeet, The Netherlands, www.ewrs.org/pwc/archive.htm.Google Scholar
Melander, B. 2005. Non-chemical weed control: new directions. in Goodman, Robert M., ed. Encyclopedia of Plant and Crop Science. New York: University of Winsconsin, Marcel Dekker. In press.Google Scholar
Melander, B., Cirujeda, A., and Jørgensen, M. H. 2003. Effects of inter-row hoeing and fertiliser placement on weed growth and yield of winter wheat. Weed Res 43:428–438.Google Scholar
Melander, B. and Hartvig, P. 1995. Weed harrowing in seeded onions. Pages 543–549 in Proceedings 9th EWRS Symposium. Challenges for Weed Science in a Changing Europe, Budapest, Hungary. Doorwerth, The Netherlands: European Weed Research Society.Google Scholar
Melander, B. and Hartvig, P. 1997. Yield responses of weed-free seeded onions [Allium cepa (L.)] to hoeing close to the row. Crop Prot 16:687–691.CrossRefGoogle Scholar
Melander, B., Heisel, T., and Jørgensen, M. H. 2002. Aspects of steaming the soil to reduce weed seedling emergence. Pages 236–237 in Proceedings of the 12th EWRS Symposium Wageningen 2002, Papendal, The Netherlands. Doorwerth, The Netherlands: European Weed Research Society.Google Scholar
Melander, B., Korsgaard, M., and Willumsen, J. 1999. Resultater og erfaringer med ukrudtsbekæmpelse i økologiske frilandsgrønsager. (Results and experiences with weed control in organic outdoor vegetables. With English summary). Pages 85–95 in Proceedings 16th Danish Plant Protection Conference/Crop Protection in Organic Farming/Pests and Diseases. Nyborg, Denmark: Danish Institute of Agricultural Sciences.Google Scholar
Melander, B. and Rasmussen, G. 2001. Effects of cultural methods and physical weed control on intrarow weed numbers, manual weeding and marketable yield in direct-sown leek and bulb onion. Weed Res 41:491–508.Google Scholar
Melander, B. and Rasmussen, K. 2000. Reducing intrarow weed numbers in row crops by means of a biennial cultivation system. Weed Res 40:205–218.Google Scholar
Melander, B., Rasmussen, K., Rasmussen, I. A., and Jørgensen, M. H. 2001. Radrensning med og uden ukrudtsharvning i vintersæd om foråret i samspil med forskellige dyrkningsfaktorer. (Row hoeing followed by weed harrowing in winter cereals in the spring under the influence of different cropping factors. With English summary). Pages 211–225 in Proceedings 18th Danish Plant Protection Conference I. Nyborg, Denmark: Danish Institute of Agricultural Sciences.Google Scholar
Mertens, S. K. and Jansen, J. 2002. Weed seed production, crop planting pattern, and mechanical weeding in wheat. Weed Sci 50:748–756.Google Scholar
Mogensen, B. B. and Spliid, N. H. 1995. Pesticides in Danish watercourses: occurrence and effects. Chemosphere 31:3977–3990.Google Scholar
Moonen, A. C. and Bàrberi, P. 2004. Size and composition of the weed seedbank after 7 years of different cover crop-maize management systems. Weed Res 44:163–177.CrossRefGoogle Scholar
Moonen, A. C., Bàrberi, P., Raffaelli, M., Mainardi, M., Peruzzi, A., and Mazzoncini, M. 2002. Soil steaming with an innovative machine—effects on the weed seedbank. Pages 230–236 in Proceedings of the 5th Workshop of the EWRS Working Group on Physical and Cultural Weed Control, March 11–13, Pisa, Italy, www.ewrs.org/pwc/archive.htm.Google Scholar
Mülle, G. and Heege, H. J. 1981. Kornverteilung über die Fläche und Ertrag bei Getreide. Z. Acker-Pflanzenb 150:97–112. [In German].Google Scholar
Oliphant, J. M. 1977. Some notes on effect of herbicide use and cultivation practice on population and control of Avena spp. in winter wheat. Exp. Husb 32:50–55.Google Scholar
Paolini, R., Caporali, F., and Campiglia, E. 1993. Yield response, complementarity and competitive ability of bread wheat (Triticum aestivum L.) and pea (Pisum sativum L.) in mixture. Agric. Mediterranea 123:114–121.Google Scholar
Parish, S. 1990. A review of non-chemical weed control techniques. Biol. Agric. Hortic 7:117–137.Google Scholar
Peruzzi, A., Raffaelli, M., Ginanni, M., and Mainardi, M. 2002. Development of innovative machines for soil disinfection by means of steam and substances in exothermic reaction. Pages 220–229 in Proceedings of the 5th Workshop of the EWRS Working Group on Physical and Cultural Weed Control, March 11–13, Pisa, Italy www.ewrs.org/pwc/archive.htm.Google Scholar
Petersen, J. 2001. Recovery of 15N-ammonium-15N-nitrate in spring wheat as affected by placement geometry of the fertiliser band. Nutr. Cycl. Agroecosyst 61:215–221.Google Scholar
Petersen, J. and Mortensen, J. V. 2002. Dry matter production and 15N recovery in spring wheat as affected by placement geometry of the fertilizer band. Commun. Soil Sci. Plant Anal 33:163–178.Google Scholar
Pinel, M. P. C., Bond, W., White, J. G., and de Courcy Williams, M. 1999. Field Vegetables: Assessment of the Potential for Mobile Soil Steaming Machinery to Control Diseases, Weeds and Mites of Field Salad and Related Crops. Final Report on HDC Project FV229. East Malling, U.K.: Horticultural Development Council. 55 p.Google Scholar
Pullen, D. W. M. and Cowell, P. A. 1997. An evaluation of the performance of mechanical weeding mechanisms for use in high speed inter-row weeding of arable crops. J. Agric. Eng. Res 67:27–34.Google Scholar
Rasmussen, I. A. 2004. The effect of sowing date, stale seedbed, row width and mechanical weed control on weeds and yields of organic winter wheat. Weed Res 44:12–20.Google Scholar
Rasmussen, I. A., Melander, B., Rasmussen, K., Jensen, R. K., Hansen, P. K., Rasmussen, G., Christensen, S., and Rasmussen, J. 2000. Recent advances in weed management in cereals in Denmark. Page 178 in Proceedings 13th IFOAM Scientific Conference: IFOAM 2000: The World Grows Organic. Basel, Switzerland: International Federation of Organic Agriculture Movements.Google Scholar
Rasmussen, J. 1990. Selectivity—an important parameter on establishing the optimum harrowing technique for weed control in growing cereals. Pages 197–204 in Proceedings 7th EWRS Symposium 1990: Integrated Weed Management in Cereals, Helsinki, Finland. Doorwerth, The Netherlands: European Weed Research Society.Google Scholar
Rasmussen, J. 1991. A model for prediction of yield response in weed harrowing. Weed Res 31:401–408.Google Scholar
Rasmussen, J. 1993. Can high densities of competitive weeds be controlled efficiently by harrowing or hoeing in agricultural crops?. Pages 83–88 in Thomas, J. M. ed. Non-Chemical Weed Control. Communications of the Fourth International Conference of the International Federation of Organic Agriculture Movements. Dijon, France: International Federation of Organic Agriculture Movements.Google Scholar
Rasmussen, J. 1996. Mechanical weed management. Pages 943–948 in Proceedings Second International Weed Control Congress. Copenhagen, Denmark: International Weed Science Society.Google Scholar
Rasmussen, J. 1998. Ukrudtsharvning i vinterhvede. (Weed harrowing in winter wheat. With English summary). Pages 179–189 in Proceedings 15th Danish Plant Protection Conference/Weeds. Nyborg, Denmark: Danish Institute of Agricultural Sciences.Google Scholar
Rasmussen, J. 2003. Punch planting, flame weeding and stale seedbed for weed control in row crops. Weed Res 43:393–403.Google Scholar
Rasmussen, J. and Ascard, J. 1995. Weed control in organic farming systems. Pages 49–67 in Glen, D. M., Greaves, M. P., and Anderson, H. M. eds. Ecology and Integrated Farming Systems. Chichester, U.K.: Wiley.Google Scholar
Rasmussen, J. and Pedersen, T. B. 1990. Forsøg med radrensning i korn— rækkeafstand og udsædsmængde. (Hoeing in cereals—row distances and seed rates. With English summary). Pages 187–199 in Proceedings 7th Danish Plant Protection Conference/Weeds. Nyborg, Denmark: Danish Institute of Agricultural Sciences.Google Scholar
Rasmussen, J. and Svenningsen, T. 1995. Selective weed harrowing in cereals. Biol. Agric.Hortic 12:29–46.Google Scholar
Rasmussen, K. 2002. Influence of liquid manure application method on weed control in spring cereals. Weed Res 42:287–298.Google Scholar
Rasmussen, K. and Rasmussen, J. 2000. Barley seed vigour and mechanical weed control. Weed Res 40:219–230.Google Scholar
Rasmussen, K., Rasmussen, J., and Petersen, J. 1996. Effects of fertiliser placement on weeds in weed harrowed spring barley. Acta Agric. Scand. Sect. B Soil Plant Sci 3:192–196.Google Scholar
Roberts, H. A. and Potter, M. E. 1980. Emergence patterns of weed seedlings in relation to cultivation and rainfall. Weed Res 20:377–386.Google Scholar
Ruhe, I. 2000. Winter Wheat Cultivation in Nitrogen-limited Production Systems Under Particular Consideration of Yield Formation, Organic Fertilizing and Mechanical Weed Control. Schriftenreihe des Instituts Pflanzenb. Pflanzenzuecht. Christian Albrechts Universitat zu Kiel No. 13. 181 p.Google Scholar
Søgaard, H. T. and Heisel, T. 2002. Machine vision identification of weed species based on active shape models. Pages 402–403 in Proceedings of the 12th EWRS Symposium Wageningen 2002, Papendal, The Netherlands. Doorwerth, The Netherlands: European Weed Research Society.Google Scholar
Søgaard, H. T., Jørgensen, M. H., and Nielsen, P. S. 2002. Præcision ved automatisk styring af radsensere. Grøn Viden—Markbrug 268:4 p.Google Scholar
Søgaard, H. T. and Olsen, H. J. 2003. Determination of crop rows by image analysis without segmentation. Comput. Electron. Agric 38:141–158.Google Scholar
Spliid, N. H. and Koeppen, B. 1998. Occurrence of pesticides in Danish shallow ground water. Chemosphere 37:1307–1316.Google Scholar
Terpstra, R. and Kouwenhoven, J. K. 1981. Inter-row and intra-row weed control with a hoe ridger. J. Agric. Eng. Res 26:127–134.Google Scholar
Thonke, K. E. 1991. Political and practical approaches in scandinavia towards reducing herbicide inputs. Pages 1183–1190 in Proceedings 1991 Brighton Crop Protection Conference—Weeds. Brighton, U.K.: British Crop Protection Council.Google Scholar
Tillett, N. D., Hague, T., Blair, A. M., Jones, P. A., Ingle, R., and Orson, J. H. 1999. Precision inter-row weeding in winter wheat. Pages 975–980 in Proceedings 1999 Brighton Crop Protection Conference— Weeds: Brighton, U.K.: British Crop Protection Council.Google Scholar
Tillett, N. D., Hague, T., and Miles, S. J. 2002. Inter-row vision guidance for mechanical weed control in sugar beet. Comput. Electron. Agric 33:163–177.Google Scholar
Van der Weide, R. Y., Bleeker, P. O., and Lotz, P. A. B. 2002. Simple innovations to improve the effect of the false seedbed techniques. Pages 3–4 in Proceedings of 5th EWRS Workshop on Physical and Cultural Weed Control. Pisa, Italy, www.ewrs.org/pwc/archive.htm.Google Scholar
Weber, H. 1997. Geräte- und verfahrentechnische Optimierung der mechanischen Unkrautregulierung in Beetkulturen. (With English summary). Ph.D. dissertation, Institut für Landtechnik der Technischen Universität München, München, Germany. 201 p.Google Scholar
Weiner, J., Griepentrog, H. W., and Kristensen, L. 2001. Suppression of weeds by spring wheat Triticum aestivum increases with crop density and spatial uniformity. J. Appl. Ecol 38:784–790.Google Scholar
Welsh, J. P., Bulson, H. A. J., Stopes, C. E., Froud-Williams, R. J., and Murdoch, A. J. 1996. Weed control in organic winter wheat using a spring-tine weeder. Pages 1127–1132 in Proceedings Second International Weed Control Congress. Copenhagen, Denmark: International Weed Science Society.Google Scholar
Welsh, J. P., Phillips, L., Bulson, H. A. J., and Wolfe, M. 1999. Weed control strategies for organic cereal crops. Pages 945–950 in Proceedings 1999 Brighton Crop Protection Conference—Weeds. Brighton, U.K.: British Crop Protection Council.Google Scholar
Wilson, B. J., Wright, K. J., and Butler, R. C. 1993. The effect of different frequencies of harrowing in the autumn or spring on winter wheat, and on the control of Stellaria media (L.) Vill., Galium aparine L. and Brassica napus L. Weed Res 33:501–506.Google Scholar
Wiltshire, J. J. J., Tillett, N. D., and Hague, T. 2003. Agronomic evaluation of precise mechanical hoeing and chemical weed control in sugar beet. Weed Res 43:236–244.Google Scholar
Zanin, G., Borin, M., Altissimo, L., and Calamari, D. 1993. Simulation of herbicide contamination of the aquifer north of Vicenza (North-East Italy). Chemosphere 26:929–940.Google Scholar
Zanin, G. and Catizone, P. 2003. La malerbologia. Pages 195–269 in Evoluzione dei mezzi di difesa fitosanitaria. I Georgofili—Quaderni 2003-I. Firenze, Italy: Società Editrice Fiorentina.Google Scholar