caa a22 4500 386316066 CHVBK 20180307111605.0 cr unu---uuuuu 161130s1988 xx s 000 0 eng 10.1017/S0889189300002447 doi S0889189300002447 pii (NATIONALLICENCE)cambridge-10.1017/S0889189300002447 Using crop diversity to manage pest problems: Some California examples [Elektronische Daten] Moderate to large scale California growers (as well as small scale ones) manipulate cropping patterns in a number of ways to reduce pest problems. Crop rotation, which can be defined as diversifying crops over time, is used to manage selected pests, primarily weeds, pathogens, and nematodes. As a substitute for pesticides, crop rotation has been most rewarding in the control of nematodes; sugarbeet cyst and root knot nematode examples are detailed. Some pests that invade fields from nearby areas can be managed by modifying adjacent cropping patterns or practices; Pierce's disease of grapes, sugarbeet yellows and border harvesting of alfalfa are given as examples. Finally, multiple crops can be grown within a single field or orchard. Although this approach is not widely practiced by many California growers, two examples of systems where intercropping has been shown to limit pest numbers without the use of pesticides are described: intercropping of cotton with alfalfa and companion planting oats when seeding alfalfa. These examples show that using crop diversification to manage pests is feasible, but growers must be strongly motivated to make the necessary changes in cropping patterns. Most of the systems that have been widely adopted are those for which few other economically feasible methods were available. Copyright © Cambridge University Press 1988 cropping patterns nationallicence weeds nationallicence insects nationallicence pathogens nationallicence nematodes nationallicence pest management nationallicence crop rotation nationallicence crop diversity nationallicence intercropping nationallicence multiple crops nationallicence economic feasibility nationallicence Flint Mary Louise IPM Specialist, IPM Education and Publications, Statewide IPM Project, University of California, Davis, CA 95616. Roberts Philip A. Associate Nematologisi, Nematology Department, University of California, Riverside, CA 92521. American Journal of Alternative Agriculture Cambridge University Press 3/4(1988), 163-167 0889-1893 3:4<163 1988 3 AJA https://doi.org/10.1017/S0889189300002447 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0889189300002447 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Flint Mary Louise IPM Specialist, IPM Education and Publications, Statewide IPM Project, University of California, Davis, CA 95616 NATIONALLICENCE 700 1- Roberts Philip A. Associate Nematologisi, Nematology Department, University of California, Riverside, CA 92521 NATIONALLICENCE 773 0- American Journal of Alternative Agriculture Cambridge University Press 3/4(1988), 163-167 0889-1893 3:4<163 1988 3 AJA CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge