Progress 09/15/01 to 09/14/04
Outputs
A major experimental emphasis in the project was finding new methods for nutsedge control for organic vegetable growers. Because nutsedge is does not tolerate shade, a series of crop rotation were tested for their ability to shade nutsedge. Those rotation that formed a dense canopy for the longest period of time were the most effective. Yellow nutsedge was less aggressive and had little effect on either broccoli or cantaloupe. Purple nutsedge decreased the yield of most crops. However when purple nutsedge is controlled by cultivation or solarization treatments, the treatments have the highest net return $1686.45 and $1270.37 respectively. We have begun an exciting program for extending information on organic vegetable production. Farm advisors, specialists, grower and industry contacts have been working together to provide the most current information available on organic vegetable production. We have developed a training manual with chapters devoted to pest
management, economics, soils, and many other relevant topics. Our plan is to conduct a series of training session across California. Our recent meeting in Salinas was standing room only, with over 100 participants. Feedback was overwhelmingly positive. Growers especially enjoyed the grower panel on pest management.
Impacts
Organic agriculture has seen exponential growth in the last 20 years. Much of the production has moved from small, part time farmers to larger growers. This project directly addresses the special needs of organic growers, beginning with research on control of nutsedge, and now culminating with a program of information delivery.
Publications
- Ngouajio, M. and M.E. McGiffen, Jr. 2004. Sustainable vegetable production: effects of cropping systems on weed and insect population dynamics. Acta Hort. 638:77-83.
- Ogbuchiekwe, E.J., M.E. McGiffen, Jr., and M. Ngouajio. 2004. Economic return in production of cantaloupe and lettuce is affected by cropping system and management practice. HortScience 39:1321-1325.
- Huang, X., M. McGiffen, and I. Kaloshian. 2004. Reproduction of Mi-virulent Meloidogyne incognita isolates on Lycopersicon spp. J. Nematol. 36:69-75
- Wang, G., J.D. Ehlers, E.J. Ogbuchiekwe, E.J., S. Yang, and M.E. McGiffen, Jr. 2004. Competitiveness of erect, semierect, and prostrate cowpea genotypes with sunflower (Helianthus annus) and purslane (Portulaca oleracea). Weed Science 52:815-820.
|
Progress 01/01/03 to 12/31/03
Outputs
Date and details of Crop Rotation within treatments 1) Crop control: Broccoli was planted on October 10, 2002 and harvested January 29 2003. Cantaloupes was planted on February 15, and harvested on June 23, 2003. Plots will remain fallow following the planting winter broccoli and summer cantaloupes. 2) Nutsedge Control: Same as treatment 1, except that nutsedge was planted before crops. 3) Cultivation: Same as Treatment 2, except that nutsedge is cultivated at first sign of emergence, and if still present, every two weeks thereafter. Labor required will be recorded and used to determine costs and net return. 4) Smothers: wheat was seeded on February 10, and harvested on April 18, 2003 as green chop silage. Sudangrass was plant over the green chopped wheat plot on April 23 and to be harvested by cutting whenever the sudangrass reaches 1.2 m in height. On November 1, plow in sudangrass and rework the soil. 5) Halosulfuron and smothers: Sweet corn was planted on February
21, 2003 and Pre application of halosulfuron was added the same day. Sweet corn was harvested in June 2, and sudangrass was planted over and to be harvested whenever the sudangrass reaches 1.2 m in height. On November 1 the sudangrass will be plowed under and beds rework. 6) Solarization control: Broccoli was planted on October 10 and harvested on January 30, 2003. Wheat was planted on February 10, 2003 following the broccoli harvest. Wheat was harvested for grain on May 30, 2003 and the plots were fallowed with out irrigation until the ground is prepared in August broccoli. 7) Solarization: Same as treatment 6, except four-mil plastic was applied to completely cover each treated plot for summer. Hot water is the control agent in solarization, so soil moisture will be maintained with periodic irrigation through drip taped buried beneath the plastic. Plastic will be removed in August, and the ground prepared for a September planting of broccoli. The treatments were replicated five
times in a randomized complete block design. Yield and quality of all crops was measured at each harvest for marketable products. For all treatments, broccoli will be planted in Sept 2004 without any nutsedge control. This will provide data on the effect of two field seasons of treatment on nutsedge populations and cantaloupe yield. Sampling tubers after each crop, and with mid-season shoot counts will also monitor Nutsedge populations. Yellow nutsedge was less aggressive and had little effect on either broccoli or cantaloupe. Purple nutsedge decreased the yield of most crops. However when purple nutsedge is controlled by cultivation or solarization treatments, the treatments have the highest net return $1686.45 and $1270.37 respectively.
Impacts
Crop rotation with smothering crops and solarization effectively managed nutsedge populations to allow organic vegetable production. The research shows the economic benefits of combining several control methods to reduce costs and increase effectiveness.
Publications
- Ngouajio, M., M.E. McGiffen, Jr., and C.M. Hutchinson. 2003. Effect of cover crop and management system on weed populations in lettuce. Crop Protection 22(1):57-64
- Wilen, C.A., M.E. McGiffen, Jr., and C.L. Elmore. 2003. Nutsedge. Pest Notes Number 7432, University of California Statewide Integrated Pest Management Program, Davis, CA.
- McGiffen, Jr., M.E. 2003. Alternatives for Purple and Yellow Nutsedge Management. 2003 Proceedings of the California Weed Science Society 55: 150-151.
- Wang, G., J. Ehlers, E. Ogbuchiekwe, and M.E. McGiffen, Jr. 2003. Competition Between Cowpea Cover Crop Varieties and Weeds. 2003 Proceedings of the California Weed Science Society 55: 150-151.
- Ogbuchiekwe, E.J., M. Ngouajio, and McGiffen, M.E. 2003. Economic return for lettuce and cantaloupe is affected by cropping system and management practice. Weed Science Society of America Abstracts 43:9.
- Wang, G., Ehlers, J., Ogbuchiekwe, E.J., and McGiffen, M.E. 2003. Economic return for lettuce and cantaloupe is affected by cropping system and management practice. Weed Science Society of America Abstracts 43:9.
- Tedeschini, J., B. Stamo, H. Pace, B. Huqi, M.E. McGiffen, Jr., and L. Ferguson. 2003. Organic methods of vegetation management. 4th National Integrated Pest Management Symposium p. 78.
- Wang, G., J. Ehlers, E. Ogbuchiekwe, and M.E. McGiffen, Jr. 2003. Cowpea varietal resistance to weeds. 4th National Integrated Pest Management Symposium p. 85.
- Wang, G., J. Ehlers, E.J. Ogbuchiekwe, and M.E. McGiffen, Jr. 2003. Competition between cowpea cover crop varieties and weeds. Weed Science Society of America Abstracts 43:8.
- McGiffen, M.E., Jr., I. Lebron, and M. Ngouajio. 2001. Organic And Other Alternative Cultural Systems For Carrots. 2001 Annual Report, California Fresh Carrot Advisory Board, pp. 83-100.
|
Progress 01/01/02 to 12/31/02
Outputs
Vegetable growers identified nutsedge as the major weed problem for southern California. We began a multiyear experiment to determine if crop rotation and other cultural practices were effective controls. Initial results are promising, especially when crops form shading canopies during the warmer months. Results were presented at several grower and agri-industry meetings. We found significant reductions in weed populations when mixtures of cowpea and sudangrass were grown as cover crops. Growers are anxiously awaiting new varieties with enhanced pest resistance. We have collaborated with breeders to develop new varieties of cowpea that shade out weeds and resist other pests. These varieties should be ready for release in a few years. Collaboration with colleagues across America has led to a series of articles in American Vegetable Grower magazine on alternative weed control. We are in the planning stages for a series of training sessions and a new manual on organic
vegetable production. Cost of production studies have been developed for various management options in a spreadsheet format that growers can readily adapt to their situation. We are working to expand our activities with the many NGO's that serve the organic community, principally by providing them information to disseminate to their clientele.
Impacts
Growers will have new cultural tools to manage nutsedge and other weeds. This is obviously essential for organic growers, who have fewer weed management tools. But conventional growers are also very interested in our nonchemical methods, as many crops are losing pesticide registrations. Our training sessions fill a void for practical information on how to grow organically. We believe they will serve growers nationwide, and should be useful for more crops than just vegetables. The American Vegetable grower articles will be immediately available to vegetable growers across America.
Publications
- Ngouajio, M., M.E. McGiffen, Jr., and C.M. Hutchinson. 2003. Effect of cover crop and management system on weed populations in lettuce Crop Protection 22(1):57-64
- McGiffen, Jr., M.E., M. Ngouajio, D. Crowley, J. Borneman, C.M. Hutchinson. 2002. Soil organic amendments change low organic matter agroecosystems. International Horticultural Congress and Exhibition 26:289.
- Ngouajio, M. and M.E. McGiffen, Jr. 2002. Sustanable vegetable production: Effects of cropping systems on weed and insect population dynamics. International Horticultural Congress and Exhibition 26:279-280.
|
|