Source: MICHIGAN STATE UNIV submitted to
STRATEGIES TO ENHANCE THE SUSTAINABILITY OF INTENSIVE VEGETABLE PRODUCTION SYSTEMS
Sponsoring Institution
NIFA
Project Status
REVISED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0193779
Grant No.
(N/A)
Project No.
MICL02011
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Aug 1, 2007
Project End Date
Jul 31, 2012
Grant Year
(N/A)
Project Director
Ngouajio, M.
517-355-5191
ngouajio@msu.edu
Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824
Performing Department
HORTICULTURE
Non Technical Summary
Because of the increased use of short-term crop rotations, soil fertility has declined, and the incidence of weeds and soil-borne diseases has increased. As a consequence, it has become difficult for growers to maintain high yield and product quality. We propose to use cover crops, bio-fumigants, and other soil amendments to develop and test new strategies for improvement of the sustainability of intensive vegetable production systems.
Animal Health Component
50%
Research Effort Categories
Basic
20%
Applied
50%
Developmental
30%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20514991060100%
Knowledge Area
205 - Plant Management Systems;

Subject Of Investigation
1499 - Vegetables, general/other;

Field Of Science
1060 - Biology (whole systems);
Keywords
vegetable
sustainable-agriculture
crop-rotation
cover-crop
cropping-system
physiology
ecology
agronomic-crop
soil-fertility
organic
weed
biofumigant;
Goals / Objectives
Our goal is to improve the sustainability of intensive vegetable production systems through the use of cover crops, soil amendments, and alternative production strategies. Specific objectives are: 1. Identify and minimize limitations to the integration of cover crops into short term vegetable rotation systems 2. Study the potential to use bio-fumigants as alternatives to Methyl Bromide and to improve vegetable cropping systems. 3. Develop alternative production methods for management of replant suppression problems in asparagus. 4. Determine the impact of the new cropping systems on soil quality.
Project Methods
Obj. 1. The treatments include: 1) oilseed radish, arugula, oriental mustard, wheat and a bareground control. The rotation system will be carrot (2006)-butternut squash (2007)-snap bean or soybean (2008)-Carrot (2009). Data collection for each year will include: Cover crop growth and biomass production, soil nutrient availability, nematode community structure (MSU plant diagnostic clinic), crop yield and quality. A greenhouse study will test the sensitivity of the cover crops to herbicides applied in the cash crops. Bioassays will be conducted using soil collected from the field and soil treated with low rates of the herbicides. Results of this study will be used to limit the risk of herbicide injury and enhance cover crop establishment and biomass production in the rotation systems. Obj. 2. The treatments will include: Oriental mustard, Oilseed, Yellow mustard Methyl bromide, and Control. The Brassica cover crops will be planted on April, 2007 and will be flail mowed and incorporated into the soil as green manure at flowering stage. The plot will be irrigated immediately after cover crop incorporation to seal the soil surface and maximize the bio-fumigation effect. After a two-week plant-back period, eggplant and muskmelon will be transplanted and direct seeded, respectively on raised beds covered with black plastic mulch and drip irrigated. Data collection will include nutrient cycling, the incidence of soil-borne diseases, mainly Fusarium and Verticillium, crop yield and produce quality. Data will be subjected to ANOVA (Analysis Of Variance) and means separated using LDS (5% level of probability). Obj. 3. Greenhouse and field experiments will be conducted to test the possibility of using greenhouse-grown transplants as alternative planting materials for asparagus establishment. Various transplant plug cell size and shape will be tested in the greenhouse. Growth analyses will be performed on the collected data. Non linear regression analysis will be performed to identify the optimal duration of transplant production and the appropriate plug cell size required. Field experiments will compare the performance of greenhouse-grown transplants with one-year-old crowns. Another trial will test strategies to reduce replant suppression problems. A split plot design will be used. The main plot effect will be sanitation with two levels: a) clean field (all dead crowns and plant material removed) and b) dirty field (plant materials left in the field). The subplot factor with include the following treatments: a) compost application, b) subsoiling, c) fumigation and d) control. Data collection will include plant stand, fern growth and development, disease incidence and yield. Obj. 4. Soil samples will be collected in the top 15 cm of each cropping system to measure soil microbial activity, metabolic fingerprinting, and nematode community structure. For soil microbial activity, the fumigation incubation will be used. For metabolic fingerprinting, BIOLOG Ecoplates technique will be used. Nematode community structure will be conducted at Michigan State University Diagnostic Clinic.

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: In 2011, field, greenhouse, and laboratory experiments were conducted to test strategies for sustainable vegetable production. These included cover crops, soil amendments, low tunnels, and alternative cultural practices. A total of 12 cover crops were screened in the greenhouse for their susceptibility to P. Capsici. Vegetables with a known susceptibility to the disease were also included in the test as positive controls. As expected, disease evaluation showed death of summer squash and bell peppers. The only cover crop that showed disease symptoms was yellow mustard cultivar Tilney and disease symptoms were minor. However, biomass accumulation of Tilney was not affected by the presence of the pathogen. All other cover crops showed no symptoms throughout the experiment and no effect on biomass production. Surprisingly the total biomass of Oriental mustard Pacific Gold increased in the presence of P. Capsici. Field studies were conducted to test and demonstrated the impact of alternative cultural practices on asparagus performance in a replant situation. These included two large-scale on-farm studies evaluating effects of soil amendments, a study comparing the performance of production fields established with greenhouse-grown transplants with that of fields established with standard field-grown one-year-old crowns, and a study investigating the potential to integrate brassica cover crops into asparagus production systems. Yield data from the experiments demonstrate that appropriate soil amendment, use of brassica cover crops and cultivar selection are all critical component of asparagus cropping systems and have high potentials to enhance yield in a replant situation. Impacts on field life span are ongoing and will require multiple years of data collection. Studies evaluating the impact of low tunnels on cucumber and tomato production showed significant improvements in frost protection and earliness. The use of low tunnels allowed harvesting cucumbers two to three weeks earlier than the rest of the industry. Results from these studies were presented to growers at the Great Lakes Fruit, Vegetable and Farm Market Expo and other local, regional, and international meetings, including: ASHS annual Meeting in Hawaii; Asparagus reporting meeting; Celery Reporting Meeting; Great Lakes Vegetable Working Group; Oceana County Asparagus Day. Results were also published in scientific journals magazines and newsletters. PARTICIPANTS: Dr. Mathieu Ngouajio is the overall project Director. He oversees all activities related to this project. Dr. Bernard Zandstra conducted greenhouse studies to elucidate the impact of residual herbicides on cover crop establishment, and herbicide safety on asparagus transplants. Dr. Darryl Warncke studied the impact of soil fertility on asparagus production and cover crops performance. Mr. Drey Clark provided technical support for all field and greenhouse studies with the help of Aristarque Djoko and Damen Kurzer. Mr. Norman Myers coordinated most extension activities. Ajay Nair, Zachary Hayden, and Rebekah Struck, were graduate students working on the project. They helped with field, greenhouse, and laboratory activities. TARGET AUDIENCES: The main audiences were: Vegetable growers; Organic growers; Extension educators; and graduate students. These audiences were reached through classroom and laboratory teaching, as well as extension and outreach activities. Overall, we reached a very conservative number of 4,000 people (growers, extension educators, scientists, students etc.) in 2011 through various activities including field tours, demonstrations, workshops, scientific publications and newsletter articles. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Preliminary results from greenhouse experiments show that none of the brassica cover crops tested was susceptible to Phytophthora. Although yellow mustard cultivar Tilney showed minor symptoms, it growth and development was not affected. Based on these results and previous field studies the brassica cover crops tested could be used in vegetable crop rotation with low risk of increasing P. capsici infestation. Early observations indicate improved asparagus yield with either soil amendment with compost or brassica cover crops. These findings confirm the benefits of improving crop diversity in asparagus and other crops production systems. Many asparagus growers have already adopted brassica cover crops as a mean to improve crop rotation. The use of low tunnels will help fresh market vegetable growers improve profitability by harvesting earlier when prices are competitive. Growers, extension educators, and industry representatives toured research plots in 2011.

Publications

  • Nair A. and M. Ngouajio. 2011. Integrating Brassica Cover Crops Into Onion Cropping Systems: Implications for Plant Population, Stand Establishment, and Yield. HortScience 46(9):S203.
  • Ngouajio M., J.W. Counts, and D. Clark. 2011. Effect of compost and brassica cover crops on soil quality and asparagus performance. Abstr. Book of Abstracts Intl. Symp. Organic Matter and Compost Use in Horticulture. 4-7 April, 2011, Adelaide, Australia. P55.
  • Ngouajio M. 2011. Hot and sunny days promote sunscald in peppers and other vegetables. Michigan State University Extension News for Agriculture; August 2, 2011. Available at URL: http://news.msue.msu.edu/news/article/hot_and_sunny_days_promote_suns cald_in_peppers_and_other_vegetables
  • Ngouajio M. 2011. The upcoming heat wave may be conducive to black streak development in celery; July 18, 2011. Available at URL: http://news.msue.msu.edu/news/article/the_upcoming_heat_wave_may_be_c onducive_to_black_streak_development_in_cele
  • Ngouajio M and N. Myers. 2011. Integrated management of asparagus following the end of the harvest period. Michigan State University Extension News for Agriculture; June 29, 2011. Available at URL: http://news.msue.msu.edu/news/article/integrated_management_of_aspara gus_following_the_end_of_the_harvest_period
  • Ngouajio M. 2011. The high-risk time for black streak development in celery has passed. Michigan State University Extension News for Agriculture; June 22, 2011. Available at URL: http://news.msue.msu.edu/news/article/the_high_risk_time_for_black_st reak_development_in_celery_has_passed
  • Ngouajio M. 2011. Using the right planting density is critical for optimum yield and revenue for vegetable crops. Michigan State University Extension News for Agriculture; June 1, 2011. Available at URL: http://news.msue.msu.edu/news/article/using_the_right_planting_densit y_is_critical_for_optimum_yield_and_revenue
  • Ngouajio M. 2011. Avoiding high-risk period may help prevent Black Streak development in celery. Michigan State University Extension News for Agriculture; May 25, 2011. Available at URL: http://news.msue.msu.edu/news/article/avoiding_high_risk_period_may_h elp_prevent_black_streak_development_in_cele
  • Ngouajio M. 2011. Managing microclimate in low tunnels for optimum crop performance. Michigan State University Extension News for Agriculture; May 25, 2011. Available at URL: http://news.msue.msu.edu/news/article/managing_microclimate_in_low_tu nnels_for_optimum_crop_performance
  • Ngouajio M. 2011. Why should growers observe a plant-back period following cover crop kill. Michigan State University Extension News for Agriculture; May 18, 2011. Available at URL: http://news.msue.msu.edu/news/article/why_should_growers_observe_a_pl ant_back_period_following_cover_crop_kill
  • Ngouajio M. and D. Clark. 2011. Cover Crops as Strategy to Enhance Biodiversity in Perennial Cropping Systems: The Case of Asparagus Production. HortScience 46(9):S203.
  • Ngouajio M. 2011. Managing plastic mulches profitably. Michigan State University Extension News for Agriculture; May 18, 2011. Available at URL: http://news.msue.msu.edu/news/article/managing_plastic_mulches_profit ably
  • Ngouajio M. 2011. Proper transplant hardening off may be a deal breaker for your season. Michigan State University Extension News for Agriculture; May 11, 2011. Available at URL: http://news.msue.msu.edu/news/article/proper_transplant_hardening_off _may_be_a_deal_breaker_for_your_season
  • Ngouajio M. 2011. Cover crops need to be managed properly. The Vegetable Growers News (Print Version only). September 2011, P9.
  • Ngouajio M. 2011. Greenhouse transplants for asparagus production. The Vegetable Growers News. Print version September 2011, p 11. Online version http://vegetablegrowersnews.com/index.php/magazine/article/greenhouse -transplants-for-asparagus-production
  • Ngouajio M. 2011: Cover Crops. Spudman Magazine. July/August Issue 2p. Available at http://spudman.com/index.php/magazine/article/cover-crops.
  • Ngouajio M. 2011. Heat wave may be conducive to black streak development in celery (Online version only): http://vegetablegrowersnews.com/index.php/news/release/13568
  • Ngouajio M. 2011. Proper transplant hardening off may be a deal breaker for your season (Online version only): http://vegetablegrowersnews.com/index.php/news/release/12849
  • Ackroyd J.V. and M. Ngouajio. 2011. Brassicaceae cover crops affect seed germination and seedling establishment in cucurbit crops. HortTechnology 21:525-532.
  • Kijchavengkul T., R. Auras, M. Rubino, S. Selke, M. Ngouajio, R.T. Fernandez. 2011. Formulation selection of aliphatic aromatic biodegradable polyester film exposed to UV/solar radiation. Polymer Degradation and Stability 96:1919-1926.
  • Nair, A., M. Ngouajio, and J. Biernbaum. 2011. Alfalfa-based organic amendment in peat-compost growing medium for organic tomato transplant production. HortScience 46:253-259
  • Nair A., M. Ngouajio, and J. Biernbaum. 2011. Evaluation of Alfalfa-Based Organic Amendment in Peat-Compost Growing Medium for Organic Transplant Production. HortScience 46(9):S60.
  • Faivor R.M.S. and M. Ngouajio. 2011. Low Tunnel Strategies for Microclimate Modification and Early Vegetable Production. HortScience 46(9):S237.
  • Hayden Z.D., M. Ngouajio, and D.C. Brainard. 2011. Rye-Vetch Cover Crop Species Proportion and Polyethylene Mulch Affect Total Biomass Production, Soil Nitrate Accumulation and Bell Pepper Yield. HortScience 46(9):S258.


Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Field, greenhouse, and laboratory experiments were conducted in 2010 to test new strategies for sustainable vegetable production. These included cover crops, soil amendments, row covers, and alternative cultural practices for production under suboptimal conditions. A study testing the impact of cover crops and organic amendments on soil microbial activity (SMA) and tomato yield under organic production systems showed that soil microbial biomass was enhanced with the combination of rye cover crop and compost application. Also, the highest marketable tomato yield was recorded when rye and hairy vetch mixtures were followed with compost application. In a separate study testing various rye and hairy vetch cover crop mixtures, we found that the proportion of each species in the mixture was critical for their performance. The relative proportions of the component species in the mixture determined total biomass production and nitrogen fixation by hairy vetch. Brassica cover crops (brown mustard, oilseed radish, yellow mustard, and Oriental mustard) were evaluated for performance in various cropping systems. Weed suppression in the range of 10 to 40% (mineral soil) and 30 to 90% (muck soil) was generally achieved especially during the first month following cover crop incorporation. However, supplemental weed control was needed for acceptable weed management. Crop establishment seemed to be a major problem especially with direct seeded species. For example, we observed almost 100% loss in melon stand when the crop was seeded within the first two weeks following biofumigation. It appears that under Michigan growing conditions, allowing sufficient time between biofumigation (cover crop residue incorporation) and crop planting is critical. The greatest increases in crop yield (5 to 20%) were observed for celery and onion when biofumigation was conducted in the fall and the cash crop planted the following spring/summer. Studies evaluating row covers showed a marked increase in the growing degree-day accumulations under floating rowcovers when compared with uncovered treatment. The impact of floating rowcovers on cucumber growth was significant. Use of rowcovers increased vine length, flower count, leaf area, leaf count, plant biomass, and total marketable yield. Low tunnels were evaluated for frost protection and earliness in tomato and cucumber production. Both the single and the double layer low tunnels were able to protect cucumber and tomato when outside temperature was as low as 29 oF. This allowed harvesting cucumbers two to three weeks earlier than the rest of the industry. Results from these studies were presented to growers at the 2010 Great Lakes Fruit, Vegetable and Farm Market Expo and other local regional and international meetings, including: ASHS annual Meeting; Asparagus reporting meeting; Celery Reporting Meeting; MOSES (Midwest Organic and Sustainable Education Service) Organic Farming Conference; Great Lakes Vegetable Working Group; Oceana County Asparagus Day. Results were also published in HortScience, Agronomy Journal, Polymer Degradation and Stability, Journal of Sustainable Agriculture, and Food Chemistry. PARTICIPANTS: Dr. Mathieu Ngouajio is the overall project Director. He oversees all activities related to this project. Dr. Bernard Zandstra conducted greenhouse studies to elucidate the impact of residual herbicides on cover crop establishment, and herbicide safety on asparagus transplants. Dr. Darryl Warncke studied the impact of soil fertility on asparagus production and cover crops performance. Mr. James W. Counts and Drey Clark provided technical support for all field and greenhouse studies. Mr. Norman Myers coordinated most extension activities. Ajay Nair, Zachary Hayden, Victoria Ackroyd, and Rebekah Struck, were graduate students working on the project. They helped with field, greenhouse, and laboratory activities. TARGET AUDIENCES: The main audiences were: Vegetable growers; Organic growers; Extension educators; and graduate students. These audiences were reached through classroom and laboratory teaching, as well as extension and outreach activities. Overall, we reached a very conservative number of 2,000 people (growers, extension educators, scientists, students etc.) in 2010 through various activities including field tours, demonstrations, workshops, newsletters etc. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Results of studies on brassica cover crops have helped celery and onion growers improve their yield by 8 to 15% on muck soils. Growers using our cover crop recommendations have reported an average of 10% celery yield increase. In 2009, about 1,900 acres of celery were harvested in Michigan with a total value of $14,898,000 (2010 statistics). With a very conservative value of 5% yield increase this could represent potentially over $700,000 benefit per year for the entire industry. There are also promising results on onions, asparagus, and other crops. Our work showed that adoption of brassica cover crops by onion growers could help reduce onion seeding rate on muck soils by 25% while increasing yield by 15.4%. With the phase out of methyl bromide vegetable growers are interested in long-term alternatives and results of trials on biofumigants show that brassica cover crops should be seriously considered as important tools for integrated vegetable crop management. The study of alternative cultural practices in asparagus will help growers extend the life span of their fields. The use of row covers and low tunnels will help fresh market vegetable growers improve profitability by harvesting earlier when prices are competitive. Growers, extension educators, and industry representatives toured research plots in 2010.

Publications

  • Kijchavengkul T., Auras R., Rubino M., Selke S., Ngouajio M., and Fernandez R. T. 2010. Biodegradation and hydrolysis rate of aliphatic aromatic polyester. Polymer Degradation and Stability (In press).
  • Nair, A. and Ngouajio M. 2010. Integrating row covers and soil amendments for organic cucumber production: Implications on crop growth, yield, and microclimate. HortScience 45(4):566-574.
  • Saidi M., Itulya F. M., Aguyoh J., and Ngouajio M. 2010. Effects of cowpea leaf harvesting initiation time and frequency on tissue nitrogen content and productivity of a dual purpose cowpea-maize intercrop. HortScience, 45:369-375. 2010.
  • Saidi M., Itulya F. M., Aguyoh J., and Ngouajio M. 2010. Leaf harvesting time and frequency affect vegetative and grain yield of cowpea. Agron. J. 102:827-833.
  • Wang, G., Ngouajio, M., and Charles, K.S. 2010. Brassica biofumigants improve onion (Allium cepa L.) and celery (Apium graveolens) production systems. Journal of Sustainable Agriculture, 34:2-14.
  • Mulabagal, V., Ngouajio, M., Nair, A., Zhang, Y., Gottumukkala, A.L., and Nair, M.G. 2010. In vitro evaluation of red and green lettuce (Lactuca sativa) for functional food properties. Food Chemistry, 118:300-306.
  • Ngouajio M., Struck R., and Clark D. 2010. Changes in tomato morphological development in response to light manipulation using colored plastic films: Concept and preliminary observations. Abstract 36th National Agricultural Plastics Congress, July 31-August 1, Palm Desert California.
  • Hao J., Hausbeck M., Grumet R., Ngouajio M., and Davis R. M. 2010. Detection and Management of Phytophthora and Pythium in Carrot, Tomato, Cucurbits, and Asparagus. HortScience 45(8):S268.
  • Nair A. and Ngouajio M. 2010. Impact of Cover Crops and Organic Amendments on Soil Microbial Activity (SMA) and Tomato yield under organic production systems. HortScience 45(8):S138.
  • Ngouajio M., Wang G., and Goldy R. 2010. Biofumigation with Brassica cover crops: Evaluation of performance in vegetable cropping systems. HortScience 45(8):S75-76.
  • Hayden, Z.D., Ngouajio, M., and Brainard, D.C. 2010. Investigating component species proportions in a cereal-legume cover crop mixture under organic management. Poster Presentation. International Horticulture Congress, Lisbon, Portugal.
  • Ngouajio M. 2010. The potential of Brassica: A one-size-fits all approach won t work when using cover crops as biofumigants in vegetables. American vegetable Growers October: 35-36.
  • Ngouajio M., Stevens H., Myers N. and Goldy R. 2010. Opportunities abound for growers at Great Lakes EXPO. The Vegetable Growers News. 44(8):22.
  • Ngouajio M. and Grumet R. 2010. Low male flower formation might affect fruit set. The Vegetable Growers News. 44(6):24-24.
  • Ngouajio M. 2010. Use of cover crop to improve onion rotation. Onion World, Jan. 2010:18-19.
  • Nair A. and Ngouajio M. 2010. Keep the greenhouse clean: Sanitation is key to reducing pest problems. American Vegetable Grower, April 2010:31-32.
  • Ngouajio M. 2010. Planning for next growing season begins now: Cover crop options after harvest of early vegetables. CAT Alert 25(16):1-2 August 11.
  • Ngouajio M. 2010. Hot weather requires careful management of celery to avoid black streak disorder. CAT Alert Vol 25:July 7.
  • Ngouajio M. 2010. Managing row covers to avoid heat injury and poor pollination. CAT Alert 25(6):3 June 2.
  • Ngouajio M. 2010. Strategies to mitigate losses due to black streaks in celery. CAT Alert 25(5):4. May, 26.
  • Ngouajio M. 2010. Male flower formation is critical for fruit set in summer squash. CAT Alert 25(5):3-4. May, 26.


Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: Field, greenhouse, and laboratory experiments were conducted in 2009 to test new strategies for sustainable vegetable production. These included cover crops, soil amendments, and alternative methods for production of disease-free asparagus planting materials. As in previous years, studies with brassica cover crops (biofumigants) increased celery and onion yields on muck soils. Oilseed radish and yellow mustard also improved onion stand establishment. Therefore, growers could reduce their onion seeding rates slightly with no yield loss if appropriate cover crops and management practices are used. When tested as alternative to methyl bromide for management of Verticillium in eggplant and melon, cover crops had limited impact on disease incidence and yield. Similar results were observed in cucumber on a site infested with Phytophthora. Brown mustard cover crop and metam sodium (Sectagon) have similar effects at reducing soil microbial biomass. All crucifers reduced soil microbial diversity and richness while metam sodium had no impact. Soil amendment affected both soil microorganism and asparagus yield. In both fumigated and non fumigated soils, compost application increased soil microbial biomass and therefore could be used as strategy to improve soil quality in asparagus production. Mustard bran on the other hand provided the most consistent benefit at increasing soil microbial richness and functional diversity. Asparagus yield seemed to be more variable in unfumigated conditions with no clear benefit of the various soil amendments. In fumigated conditions; however, the use of treated crowns alone provided adequate yield. Applying compost after soil fumigation was beneficial but with limited effect. More data should be collected over the years to clearly determine the performance of the treatments on asparagus. Asparagus transplant weight increased as plug cell size increased. Shoot and root weights were maximized with larger cells (38-cell flat) compared to smaller cells (200-cell flat). As in 2008, field established from transplants or crowns had comparable yields in 2009. Plants established from transplants produced a greater biomass than those from crowns at the end of the year. Results from these studies were presented to growers at the 2009 Great Lakes Fruit, Vegetable and Farm Market Expo and 20 others local regional and international meetings, including: a) ASHS annual Meeting, St. Louis MO. July 25-28, b) Asparagus reporting meeting, Feb. 5 2009, c) Celery Reporting Meeting, Jan. 29, d) Empire State Fruit and Vegetable Expo, Syracuse, NY Feb. 12, g) Michigan Family Farm Conference, Kalamazoo, MI Jan. 17, h) Great Lakes Vegetable Working Group, Geneva, NY, Feb 24-26, i) Oceana County Asparagus Day, Shelby, MI March 6, j) Oceana Consultant Breakfast Meeting, June 16, k) , Oceana Summer Research Tour, Sept 8, l) Onion Committee meeting Dewitt, Jan 28, m) Organic Reporting session Mar 6, n) Pickle reporting session Jan 15, o) Southwest Michigan Hort Day, Benton Harbor, Feb 4. Research results were also published in HortScicence, Crop Protection, Weed Technology, and Phytoparasitica. PARTICIPANTS: Dr. Mathieu Ngouajio is the overall project Director. He oversees all activities related to this project. Dr. Bernard Zandstra conducted greenhouse studies to elucidate the impact of residual herbicides on cover crop establishment, and herbicide safety on asparagus transplants. Dr. Darryl Warncke studied the impact of soil fertility on asparagus production and cover crops performance. Mr. James W. Counts provided technical support for all field and greenhouse studies. Mr. Norman Myers coordinated most extension activities. Ajay Nair, Zachary Hayden and Victoria Ackroyd were graduate students working on the project. They helped with field, greenhouse, and laboratory activities. TARGET AUDIENCES: The main audiences were: Vegetable growers; Organic growers; Extension educators; and graduate students. These audiences were reached through classroom and laboratory teaching, as well as extension and outreach activities. Overall, we reached a very conservative number of 1,000 people (growers, extension educators, scientists, students etc.) in 2009 through various activities including field tours, demonstrations, workshops, newsletters etc. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Results of studies on brassica cover crops have helped celery and onion growers improve their yield by 8 to 15% on muck soils. An average of 10% celery yield increase (corresponding to 150 more boxes per acre) has been reported on growers' farm using our cover crop recommendations. With a price range of $8 to $20/box this corresponds to $1,200-$3,000/A benefits. With a total of 1,800 acres harvested in Michigan (2007 statistics) this represents potentially $216,000 to $540,000 benefit per year for the entire industry. There are also promising results on onions. Our work showed that adoption of brassica cover crops by onion growers could help reduce onion seeding rate by 25% while increasing yield by 15.4%. Using 2007 statistics and values for onion seed cost ($1.50/1000 seeds), cover crop seed cost ($2.00/lb at 7 lb/A), and total crop value, this would represent total savings of $1,064,825 per year for the entire industry ($210,937 onion seed plus $888,888 increased yield minus $35,000 cover crop seed). With the phase out of methyl bromide vegetable growers are interested in long term alternatives and results of trials on biofumigants show that brassica cover crops should be seriously considered as important tools for integrated vegetable crop management. Asparagus transplant studies will help growers start new fields with disease-free planting materials, which will contribute to improved management of replant suppression problems, the biggest challenge facing the Asparagus industry Michigan and other states. Research plots were toured by growers, extension educators, and industry representatives during Oceana-Mason Summer Research Tour on 8 September, 2009.

Publications

  • Mulabagal, V., Wang, H., Ngouajio, M., and Nair, M.G. 2009. Characterization and Quantification of health-beneficial anthocyanins in leaf chicory (Cichorium intybus) varieties. European Food Research and Technology, 230:47-53.
  • Mennan, H., Ngouajio, M., Isık, D., and Kaya, E. 2009. Effects of Alternative Winter Cover Cropping Systems on Weed Suppression in Organically Grown Tomato (Solanum lycopersicum L.). Phytoparasitica, 37:385-396.
  • Mennan, H., Ngouajio, M., Kaya, E., and Isık, D. 2009. Weed management in organically grown kale using alternative cover cropping systems. Weed Technology, 23:81-88.
  • Isik, D., Kaya, E., Ngouajio, M., and Mennan, H. 2009. Summer Cover Crops for Weed Management and Yield Improvement in Organic Lettuce (Lactuca sativa) Production. Phytoparasitica, 37:193-203.
  • Isık, D., Kaya, E., Ngouajio, M., and Mennan, H. 2009. Weed suppression in organic pepper (Capsicum annuum L.) with winter cover crops. Crop Protection, 28:356-363.
  • Nair, A. and Ngouajio, M. 2009. Integrating row covers and soil amendments to improve organic cucumber production: Implications on crop microclimate and growth. Proc. 35th National Agricultural Plastics Congress. State College, PA. (CDROM).
  • Nair, A., Ngouajio, M., and Biernbaum, J. 2009. Nutrient management through compost and cover crops under organic vegetable production. Proc. Michigan State University 2009 Organic Reporting Session. East Lansing, MI.
  • Ngouajio, M. and Counts, J.W. 2009. Effect of soil amendment on soil microbial activity and asparagus yield under a replant situation. Abstract XIIth International Asparagus Symposium, Lima, Peru (P29).
  • Ngouajio, M. and Counts, J.W. 2009. Effect of biofumigation with Brassica cover crops on weed populations, soil microbial activity, and fruit rot in pickling cucumber production. Abstract 7th International symposium on chemical and non-chemical soil and substrate disinfestations SD 2009, Leuven Belgium (P79).
  • Ngouajio, M. and Counts, J.W. 2009. Harnessing brassica cover crops and onion plant population to improve onion production on muck soils. Onion World, 1:20-21.
  • Nair, A. and Ngouajio, M. 2009. Integrating row covers and soil amendments to improve organic cucumber production: Implications on crop microclimate and growth. Abstract 35th National Agricultural Plastics Congress, State College, Pennsylvania, USA.
  • Ngouajio, M. 2009. The need to integrate plant populations into cover crop seeding recommendations: Case study with two oilseed radish cultivars with contrasting seed masses, Abstract HortScience, 44:1025-1025.
  • Nair, A. and Ngouajio, M. 2009. Cover crop, nutrient amendment, and crop cultivar affect organic cucumber and tomato production systems in the Great Lakes region, Abstract HortScience, 44:1039-1040.
  • Ackroyd, V. and Ngouajio, M. 2009. Impact of brassica cover crops on eggplant transplant growth and muskmelon seed germination under field conditions. Abstract HortScience, 44:1163-1163.
  • Ngouajio, M. 2009. Lack of male flower formation in squash. CAT Alert, 24(16):6-7.
  • Ngouajio, M. 2009. A simple seed germination test may be a deal breaker. CAT Alert, 24(3):2-2.
  • Ngouajio, M. 2009. Row cover for frost protection and earliness in vegetable production. CAT Alert, 24(2):1-2.
  • Ngouajio, M. 2009. Extending the profit window: Minimize risks and maximize profit with early harvest. CAT Alert, 24(2):2-3.
  • Ngouajio M. 2009. Winter injury in rye and other cover crops. CAT Alert, 24(2):3-3.
  • Ngouajio, M. 2009. Mitigating rotation limitations in perennial crops. Vegetable Growers News, June 43(6):18.
  • Nair, A. and Ngouajio, M. 2009. An Organic Amendment: Growers must make sure their compost is ready for transplant production. American Vegetable Grower, 6:24-25.
  • Ngouajio, M. and Counts, J.W. 2009. Cover crops can be used to improve onion production. The Vegetable Growers News, 3:18-18.


Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: In 2008 field, greenhouse, and laboratory experiments were conducted to test new strategies for sustainable vegetable production. These included cover crops, soil amendments, and alternative methods for production of disease-free planting materials. Studies with brassica cover crops (biofumigants) increased celery and onion yields by 8-15% on muck soils. Oilseed radish and yellow mustard also improved onion stand establishment by 38-43%. Therefore, growers could reduce their onion seeding rates by up to 40% with no yield loss if appropriate cover crops and management practices are used. When tested as alternative to methyl bromide for management of Verticillium in eggplant and melon, cover crops had limited impact on disease incidence and yield. Similar results were observed in cucumber on a site infested with Phytophthora. Brassicas had low effect on soil microbial biomass while Sectagon, significantly reduce soil microbial biomass. A different reaction was observed on soil microbial community structure. Brassica cover crops reduced soil microbial diversity and richness while Sectagon had no impact. In asparagus production, there were no major benefits of applying soil amendments (compost, mustard bran, SoilBuilder, etc.) during the 2008 season. However, shoots in the compost treatment looked taller and larger probably due to the additional nutrients provided by the compost. Soil samples from the compost treatment showed the highest microbial biomass (150%). However, the high microbial biomass did not translate into higher microbial functional diversity. This suggests that compost application alone increased the size of the microbial population but without any change in the composition of the microbial population. On the other hand, mustard bran treatment showed high microbial diversity suggesting that there are more functional groups under that treatment. In greenhouse studies, asparagus transplant weight increased as plug cell size increased. Shoot and root weights were maximized with larger cells (38-cell flat) compared to smaller cells (200-cell flat). The observation was true for both fresh and dry weight. Field established from transplants or crowns had comparable yields in 2008. In evaluation of genetic material, asparagus cultivars varied greatly in their suitability for establishment from transplants, with "Millennium" being one of the best performers. Results from these studies were presented to growers at the 2008 Great Lakes Fruit, Vegetable and Farm Market Expo and published online at the Expo website (www.glexpo.com). Other 2008 meetings were results were disseminated include a) Oceana Consultant Breakfast Meeting, 27 May, b) Michigan's Organic Research Reporting Session, 5 March, c) Organic & Alternative Vegetable Farming and Gardening Workshop, 18 April, d) Oceana County Asparagus Day 13 March, e) Vegetable Cover Crop Workshop, 12 June, f) Oceana-Mason Summer Research Tour, 5 August, g) Essex County Associated Growers' Convention, 18Nov, Ontario, Canada, h) Great Lakes Vegetable Working Group, 27-28 Feb. Research results were also published in Agronomy Journal, HortScience, HortTechnology, and Chemosphere. PARTICIPANTS: Dr. Mathieu Ngouajio is the overall project Director. He oversees all activities related to this project. Dr. Bernard Zandstra conducted greenhouse studies to elucidate the impact of residual herbicides on cover crop establishment, and herbicide safety on asparagus transplants. Dr. Darryl Warncke studied the impact of soil fertility on asparagus production and cover crops performance. Mr. James W. Counts provided technical support for all field and greenhouse studies. Mr. Norman Myers coordinated most extension activities. Mr. Ajay Nair was a graduate student working on the project. He helped with field, greenhouse, and laboratory activities. TARGET AUDIENCES: The main audiences were: Vegetable growers; Organic growers; Extension educators; and graduate students. These audiences were reached through classroom and laboratory teaching, as well as extension and outreach activities. Overall, we reached a very conservative number of 1,500 people (growers, extension educators, scientists, students etc.) in 2008 through various activities including field tours, demonstrations, workshops, newsletters etc. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Results of studies on brassica cover crops have helped celery and onion growers improve their yield by 8 to 15% on muck soils. There are also promising results indicating that onion growers could reduce their seeding rate by up to 40% when appropriate cover crops and management practices are used. Onion seed is very expensive and this could help growers reduce inputs and potentially expand their acreage. With the phase out of methyl bromide vegetable growers are interested in long term alternatives and results of trials on biofumigants show that brassica cover crops should be seriously considered as important tools for integrated vegetable crop management. Asparagus transplant studies will help growers start new fields with disease-free planting materials, which will contribute to improved management of replant suppression problems, the biggest challenge facing the Asparagus industry Michigan and other states. Research plots were toured by growers, extension educators, and industry representatives during Oceana-Mason Summer Research Tour on 5 August, 2008.

Publications

  • Wang, G., Ngouajio, M., McGiffen, M. E. Jr., Hutchinson, C. M. 2008. Summer cover crop and in-season management system affect nitrogen availability and weed density in lettuce and cantaloupe. Agronomy Journal, 100:1587-1593.
  • Wang, G. and Ngouajio, M. 2008. Integration of cover crop, conservation tillage, and low herbicide rate for machine-harvested pickling cucumbers. HortScience, 43:1770-1774.
  • Ngouajio, M., Auras, R., Fernandez, R.T., Rubino, M., Counts, J.W. Jr., and Kijchavengkul, T. 2008. Field performance of aliphatic-aromatic copolyester biodegradable mulch films in a fresh market tomato production system. HortTechnology 18: 605-610.
  • Wang, G., Ngouajio, M., McGiffen, M. E. Jr., and Hutchinson, C. M. 2008. Summer cover crop and in-season management system affect growth and yield of lettuce and cantaloupe. HortScience 43:1398-1403.
  • Ngouajio, M., Wang, G., and Goldy, R. G. 2008. Timing of drip irrigation initiation affects irrigation water use efficiency and yield of bell pepper under plastic mulch. HortTechnology 18:397-402.
  • Kijchavengkul, T., Auras, R., Rubino, M., Ngouajio, M., Fernandez, R. T. 2008. Assessment of Aliphatic-Aromatic Copolyester Biodegradable Mulch Films. Part II: Laboratory Simulated Conditions. Chemosphere 71:1607-1616.
  • Kijchavengkul, T., Auras, R., Rubino, M., Ngouajio, M., Fernandez, R. T. 2008. Assessment of Aliphatic-Aromatic Copolyester Biodegradable Mulch Films. Part I: Field Study. Chemosphere 71:942-953.
  • Wang, G., Ngouajio, M., and Warncke, D.D. 2008. Nutrient cycling, weed suppression, and onion yield following brassica and sorghum sudangrass cover crops. HortTechnology 18(1)68-74.
  • Wang, G., McGiffen, M.E. Jr., Ngouajio, M., and Hutchinson, C. 2008. Summer cover crop and in-season management system affect nitrogen availability and weed density in lettuce and cantaloupe. Abstract HortScience 43:1106-1107.
  • Ngouajio, M., Hausbeck, M.K., and Counts ,J.W. Jr. 2008. Effects of biofumigants on pickling cucumber and summer squash production in a site infested with Phytophthora capsici. Abstract HortScience 43:1065-1066.
  • Ngouajio, M., Warncke, D.D., and Counts, J.W. Jr. 2008. Changes in onion (Allium cepa) yield and grade distribution in response to cover crop and plant population. Abstract HortScience 43:1138.
  • Ngouajio, M., Hausbeck, M.K., Goldy, R.G., and Counts, J.W. Jr. 2008. Evaluation of Brassica cover crops as potential alternative to methyl bromide for eggplant production. Abstract HortScience 43:1164.
  • Ngouajio, M., Taylor, E. C., and Wang, G. 2008. Quackgrass (Elytrigia repens) response to a hairy vetch (Vicia villosa) cover crop in vegetable cropping systems. Abstract 5th International Weed Science Congress, Vancouver Canada 23-27 June.
  • Kijchavengkul, T., Auras, R., Rubino, M., Selke, S., Ngouajio, M., and Fernandez, R.T. 2008. Compostability of "Trash Bags" Polymer Under Manure, Yard, and Food Waste Composts. 16th IAPRI world congress, Bangkok, Thailand. June 8-12.
  • Kijchavengkul, T., Auras, R., Rubino, M., Ngouajio, M., and Fernandez, R. T. 2008. Development of New Biodegradable Mulch Films: Chemical, Mechanical and Optical Properties. Abstract 34th National Agricultural Plastics Congress, 7-10 March 2008, Tampa FL.
  • Ngouajio, M., Auras, R., Fernandez, R. T., Rubino, M., Count, J., Kijchavengkul, T. 2008. Development of New Biodegradable Mulch Films: Field Performance with Tomato Production. Abstract 34th National Agricultural Plastics Congress, 7-10 March 2008, Tampa FL.
  • Ngouajio, M. 2008. Don't miss the sowing window for your brassica cover crops. CAT Alert 23(16): 2-3, August 13, 2008.
  • Ngouajio, M. 2008. Managing cereal rye cover crop to reduce crop injury and improve benefits. CAT Alert Vol. 23, June 4, 2008.
  • Ngouajio, M. 2008. Impacts of a cool spring on cover crops and vegetable crops management. CAT Alert 23(5), May 21, 2008.


Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: Multiple field experiments were conducted at the Michigan State University Horticulture Teaching and Research Center, Southwest Michigan Horticultural Experiment Station, and growers farms. Additionally, in-depth studies were conducted in the greenhouse and laboratory. Results show that intensive vegetable cropping systems could be improved by a judicious integration of appropriate cover crops in the rotation system. However, in addition to climatic conditions, several factors should be taken into consideration for choosing cover crops. These include the ability of the cover crops to serve as hosts for diseases and insects, and the herbicide use history in the rotation. Brassica species (AKA biofumigants) showed potential for use as alternatives to methyl bromide for eggplant, cucumber, and squash production in sites infested with soilborne diseases like Verticillium spp. and Phytophthora capsici. However, yield improvements during the first year were generally marginal and the level of disease suppression was not enough for the cover crops to be used as stand alone management tools. Greenhouse-grown asparagus transplants were successfully established in the field and showed a performance comparable to that of one-year-old crowns commonly used by growers. This finding suggests that transplants can be used as disease-free planting materials for asparagus establishment in a replant situation to limit replant suppression problems. Transplant cell size, adequate transplant hardening, weed and nutrient management were all important factors for success of seedling establishment and growth the first year. Studies on impacts of these factors will be conducted in future trials. Our team has also started work to understand how changes in cropping systems, especially integration of various cover crops, affect soil microbial community structure. Preliminary results indicate that crop (and cover crop) sequence in the rotation has a profound impact on soil microbial community structure. In-depth studies are ongoing to quantify shifts in soil bacterial and fungal populations in response to changes in cropping systems. Results from these studies were presented to growers at the asparagus, eggplant, onion, carrot, and celery sessions of the 2007 Great Lakes Fruit, Vegetable and Farm Market Expo and published online at the Expo website (www.glexpo.com). Other local and international meetings were results were disseminated include 1) Imlay City vegetable meeting, 12 July 2007, 2) Workshop: Pest Management in the Future: A Strategic Plan for the Michigan Carrot Industry, East Lansing MI, March 12, 2007, 3) Ontario Fruit and Vegetable Convention, St. Catharines Canada Feb 21-22, 07, 4) Veggie School, United Methodist Church, Hart, MI, Feb 8, 2007, and 5) Southwest Michigan Horticultural Days, Lake Michigan, Benton Harbor Feb 6 &7 2007. Research results were also published in Weed Technology (vol. 21:437-444), Agricultural Water Management (vol. 87: 285-291), HortScience (vol. 42:850-851 and 42: 1009-1010) and The Vegetable Growers News (41(12): 10-11). PARTICIPANTS: Dr. Mathieu Ngouajio is the overall project Director. He organized all activities related to this project. Dr. Bernard Zandstra conducted greenhouse studies to elucidate the impact of residual herbicides on cover crop establishment. Dr. Darryl Warncke conducted studies on nutrient cycling by the cover crops and impact of soil fertility on the performance of cover crops. Mr. James W. Counts provided technical support for all field and greenhouse studies. Mr. Norman Myers helped organize most extension activities related to the project especially for the asparagus component of the project. Mr. Ajay Nair was a graduate student working on the project. He helped with field, greenhouse, and laboratory activities. TARGET AUDIENCES: The main audiences were: Vegetable growers; Organic growers; Extension agents; and Graduate students. These audiences were reached through classroom and laboratory teaching, as well as extension and outreach activities. Overall, we reach a very conservative number of 1,000 people (growers, extension agents, scientists, students etc.) in 2007 through various activities including field tours, demonstrations, workshops, newsletters etc.

Impacts
Results of asparagus transplant studies will help growers start new fields with disease-free planting materials, which will contribute to improved management of replant suppression problems, the biggest challenge facing the Michigan Asparagus industry. Research plots were toured by a delegation from the Michigan Asparagus Research Committee in October. This group expressed their support for our research efforts and is interested in acquiring a mechanical transplanter to facilitate field studies. Studies on residual herbicide activity will help develop recommendations to reduce the risk of cover crop failure due to herbicide injury. With the phase out of methyl bromide vegetable growers are interested in long term alternatives and results of trials on biofumigants show that brassica cover crops should be seriously considered as important tools for integrated vegetable crop management. In 2007 e.g. many growers were unable to locate enough brassica cover crop seed for their operations.

Publications

  • Hill, E. C., Ngouajio, M., and Nair, M. G. 2007. Allelopathic potential of hairy vetch (Vicia villosa) and cowpea (Vigna unguiculata) methanol and ethyl acetate extracts on weeds and vegetables. Weed Technology, 21:437-444.
  • Ngouajio M., Wang, G., and Goldy, R. 2007. Delaying onset of drip irrigation affects growth and yield of fresh market tomato under plasticulture. Agricultural Water Management 87: 285-291.
  • Ngouajio, M., Hausbeck, M.K., and Counts, J.W. 2007. Greenhouse-grown transplants as alternative planting material for management of soilborne diseases in asparagus. HortScience 42(4): 850-851.
  • Nair, A., Ngouajio, M., Biernbaum, J.A., Brewer, M.J., Bird, G.W., Snapp, S.S., and Mutch, D.R. 2007. The impact of biodiversity during the transition to organic vegetable production. HortScience 42(4): 1009-1010.
  • Ngouajio, M. 2007. Brassica cover crops can help vegetable systems. Monthly. The Vegetable Growers News 41(12): 10-11.


Progress 01/01/06 to 12/31/06

Outputs
Intensive vegetable production and market demand for high quality produce have forced commercial growers to adopt short-term crop rotations. Enhancing plant biodiversity through cover cropping between cash crop seasons may help improve the sustainability of short-term crop rotations. Our objective was to study the potential for integrating various cover crops into short-term crop rotations, with special emphasis on cucumber-tomato, used as a model. Field and greenhouse studies were conducted throughout Michigan to quantify the benefits of cover crops on soil nutrient availability, weed population dynamics, crop yield and quality. Results indicate that a broad range of cover crop species can be successfully integrated into the cropping systems after harvest of short cycle crops, like cucumber. However, only winter hardy species could be grown after crops that require a long cycle (tomato, onion). Cucumber yield in 2002, 2003, 2004 and 2006 was generally greater and more stable in the cover crops compare to the system without cover crops. This was associated with improved weed suppression and nutrient cycling in the systems with cover crops. Additionally, the Brassica cover crops tested reduced nematode populations and increased the population of beneficial organisms in the soil. Hairy vetch provided the greatest weed suppression. Because of the low amount of residue produced by hairy vetch, it was suspected that allelopathy might be implicated in its weed suppressiveness. Further studies using hairy vetch extract confirmed the susceptibility of vegetable and weed species to hairy vetch. These results strongly suggest that, under field conditions, hairy vetch residue may cause crop injury. Therefore, growers should allow enough time for hairy vetch residue to break down before planting vegetable crops.

Impacts
Most vegetable growers in Michigan recognize the benefits of long crop rotations. However, lack of good land and the global economy, have made long crop rotations difficult to practice. Integrating cover crops into current rotation systems will be more attractive to the 1,550 Michigan vegetable growers than any technology that proposes major changes in their production systems. The use of cover crops in vegetable production systems has increased at least three fold during the last five years. Legume cover crops, like hairy vetch can fix over 50 pounds of nitrogen per acre. With a total of about 177,000 acres of vegetables in Michigan, this will correspond to 4,000 tons of nitrogen. This will result in significant savings to the industry and 4,000 fewer pounds of synthetic fertilizers applied in the field. The cropping scheme with cover crops will: 1) improve weed management; 2) protect the environment by reducing nutrient leaching after cash crop harvest and by reducing fertilizer inputs; 3) increase yield and sustainability by improving soil physical, chemical, and biological properties.

Publications

  • Ngouajio, M., Delate, K., Carey, E., Azarenko, A.N., Ferguson, J.J. and Sciarappa, W.J. 2006. Curriculum Development for Organic Horticulture: Introduction. HortTechnology 16:414-417.
  • Biernbaum, J., Thorp, L. and Ngouajio, M. 2006. Development of a Year-round Student Organic Farm and Organic Farming Curriculum at Michigan State University. HortTechnology 16:432-436.
  • Ngouajio, M., Wang, G. and Hausbeck, M.K. 2006. Changes in Pickling Cucumber Yield and Economic Value in Response to Planting Density. Crop Science 46:1570-1575.
  • Hill, E.C., Ngouajio, M. and Nair, M.G. 2006. Differential response of weeds and vegetable crops to aqueous extracts of hairy vetch and cowpea. HortScience 41:695-700.
  • Kevin, S.C., Ngouajio, M., Warncke, D.D., Poff, K.L. and Hausbeck, M.K. 2006. Integration of cover crops and fertilizer rates for weed management in celery. Weed Science 54:326-334.


Progress 01/01/05 to 12/31/05

Outputs
Intensive vegetable production and market demand for high quality produce have forced commercial growers to adopt short-term crop rotations. Integrating cover crops into short-term rotations may improve sustainability by enhancing nutrient availability and by providing some weed suppression. Our objective was to study the potential for integrating summer (SCC) and winter cover crops (WCC) into short-term crop rotations, with cucumber-tomato used as a model. Field and greenhouse studies were conducted to quantify the benefits of SCC and WCC on soil nutrient availability, weed population dynamics, crop yield and quality. Results indicate that both SCC and WCC can be successfully integrated into the cropping system after harvest of cucumbers. However, only WCC can be grown during tomato seasons because of its long growing cycle. Cucumber yield in 2002, 2003, 2004 and 2005 was generally greater and more stable in the cover crops compare to the system without cover crops. At 43 days after cover crop kill (DAK) in 2002, weed density was 40, 56, 65, and 372 plants/square m in the sorghum sudangrass, cereal rye, hairy vetch, and bare ground treatments, respectively. Similar results were found at 40 DAK in 2003. Because of the low amount of residue produced by hairy vetch, allelopathy is probably implicated in the high level of weed suppression. Further studies using hairy vetch extract confirmed the susceptibility of vegetable and weed species to hairy vetch and indicate that under field conditions, growers should avoid planting cucumber within the first two weeks after hairy vetch kill.

Impacts
Most vegetable growers in Michigan recognize the benefits of long crop rotations. However, lack of good land, and the global economy, have made long crop rotations difficult to practice. Integrating cover crops into current rotation systems will be more attractive to the 1,550 Michigan vegetable growers than any technology that proposes major changes in their production system. Legume cover crops such as hairy vetch can fix 50 pounds of nitrogen per acre. With a total of about 177,000 acres of vegetables in Michigan, this will correspond to 4,000 tons of nitrogen. This will result in significant savings to the industry and 4,000 fewer pounds of synthetic fertilizers applied in the field. The new cropping scheme will: 1) improve weed management and 2) protect the environment by reducing nutrient leaching after crop harvest and by reducing fertilizer inputs; 3) increase yield and sustainability by improving soil physical, chemical, and biological properties.

Publications

  • Davis, A. S. and Ngouajio, M. 2005. Introduction to the symposium beyond thresholds: applying multiple tactics within integrated weed management systems. Weed Sci. 53(3):368.
  • Ngouajio, M. and Mennan, H. 2005. Weed populations and pickling cucumber (Cucumis sativus) yield under summer and winter cover crop systems. Crop Protection 24:521-526.
  • Ngouajio, M. and Ernest, J. 2005. Changes in the physical, optical, and thermal properties of polyethylene mulches during double cropping. Hortscience 40(1)94-97.
  • Ngouajio, M. 2005. Historical perspective on weed control and pest management in horticultural crops: Introduction. HortTechnology 15:508-510.
  • Hill, E.C. and Ngouajio, M. 2005. Sensitivity of weeds and vegetable crops to water soluble extracts of hairy vetch (Vicia villosa) and cowpea (Vigna unguiculata). North Central Weed Sci. Soc. Abstr. 60. [CD-ROM Computer File]. North Central Weed Sci. Soc., Champaign, IL. (Dec. 2005). P.189.
  • Ngouajio, M., Hill, E. C. and Chase, W. 2005. Effects of plant density on pickling cucumber fruit quality. Abstract, ASHS, Las Vegas July 17-21. HortScicence 40:999.
  • Hill, E. C. and Ngouajio, M. 2005. Germination and radicle elongation responses of seven vegetable crops to aqueous extracts of hairy vetch (Vicia villosa) and cowpea (Vigna unguiculata). Abstract, ASHS, Las Vegas July 17-21. HortScicence 40:1021.
  • Ngouajio, M. and Goldy, R. 2005. Response of tomato to drip irrigation initiated at different growth stages. Proceedings 32nd National Agricultural Plastics Congress Charleston, SC, March 5-8 p. 26.
  • Hill, E. C. and Ngouajio, M. 2005. Quackgrass (Elytrigia repens) and Pickling Cucumber (Cucumis sativus) Response to Hairy Vetch (Vicia villosa Roth). Abstract Weed Science Society of America Annual meeting 7-10 Jan., Honolulu, Hawaii. 45:59 Available on CD.
  • Ngouajio, M. and Ernest, J. 2004. Light Transmission Through Colored Polyethylene Mulches Affects Weed Populations. Hortscience 39:1302-1304.
  • Goldy, R., Ngouajio, M. and Andresen, J. 2005. Irrigation scheduling in a drip system. Proceedings 32nd National Agricultural Plastics Congress Charleston, SC, March 5-8 p. 26-30.
  • McGiffen, M. E., Jr., Lebron, I., Ngouajio, M. and Hutchinson, C. M. 2004. A systems-level research approach to the performance of organic agriculture: a case study. In Proceedings California Organic Production and Farming in the New Millennium: A Research Symposium, Thursday July 15, 2004, International House, Berkeley, CA. p.52-58. available at URL: http://www.sarep.ucdavis.edu/Organic/CCBCfinal.pdf
  • Ngouajio, M., Hill, E., Selvaraj, M. and Charles, K. 2004. New research trends in weed science in the USA. Proceedings of the First Plant Protection Congress of Turkey, September 8-10, 2004 Samsun, Turkey P.1-7.
  • Biernbaum, J., Thorp, L. and Ngouajio, M. 2005. MSU student organic farm year-round diversified organic horticulture certificate, degree and outreach curriculum. Abstract, ASHS, Las Vegas July 17-21. HortScicence 40:989.
  • Ogbuchiekwe, E. J., Ngouajio, M. and McGiffen, M. E. 2005. Economic return in production of lettuce and cantaloupe is affected by cropping system and value of hand weeding. Abstract, ASHS, Las Vegas July 17-21. HortScicence 40:1007.
  • Ngouajio, M. and Ernest, J. 2005. Effects of weathering on plastic mulch properties and performance. Proceedings 32nd National Agricultural Plastics Congress Charleston, SC, March 5-8 p. 75.


Progress 01/01/04 to 12/31/04

Outputs
Intensive vegetable production and market demand for high quality produce have forced commercial growers to adopt short-term crop rotations. Integrating cover crops into short-term rotations may improve sustainability by enhancing nutrient availability and by providing some weed suppression. Our objective was to study the potential for integrating summer (SCC) and winter cover crops (WCC) into short-term crop rotations, with cucumber-tomato used as a model. Field and greenhouse studies were conducted to quantify the benefits of SCC and WCC on soil nutrient availability, weed population dynamics, crop yield and quality. Results indicate that both SCC and WCC can be successfully integrated into the cropping system after harvest of cucumbers. However, only WCC can be grown during tomato seasons because of its long growing cycle. Cucumber yield in 2002, 2003, and 2004 was greater in the sorghum sudangrass (SCC) and cereal rye (WCC) plots compared with plots without cover crops. Cucumber yield in the hairy vetch (WCC) plots varied with years. At 43 days after cover crop kill (DAK) in 2002, weed density was 40, 56, 65, and 372 plants/square m in the sorghum sudangrass, cereal rye, hairy vetch, and bare ground treatments, respectively. Similar results were found at 40 DAK in 2003. Because of the low amount of residue produced by hairy vetch, allelopathy is probably implicated in the high level of weed suppression. Further studies will be conducted to determine the processes underlying the weed suppressiveness of hairy vetch.

Impacts
Most vegetable growers in Michigan recognize the benefits of long crop rotations. However, lack of good land, and the global economy, have made long crop rotations difficult to practice. Integrating cover crops into current rotation systems will be more attractive to the 1,550 Michigan vegetable growers than any technology that proposes major changes in their production system. Legume cover crops such as hairy vetch can fix 50 pounds of nitrogen per acre. With a total of about 177,000 acres of vegetables in Michigan, this will correspond to 4,000 tons of nitrogen. This will result in significant savings to the industry and 4,000 fewer pounds of synthetic fertilizers applied in the field. The new cropping scheme will: 1) improve weed management and 2) protect the environment by reducing nutrient leaching after crop harvest and by reducing fertilizer inputs; 3) increase yield and sustainability by improving soil physical, chemical, and biological properties.

Publications

  • Ngouajio M., Hausbeck, M.K., Sullen, D.M., Selvaraj, M. and Charles, K. 2004. The effects of plant populations on pickling cucumber canopy dynamics and yield. HortScience 39:871.
  • Ogbuchiekwe, E. J., McGiffen, M. E. Jr. and Ngouajio M. 2004. Economic return in production of lettuce and cantaloupe is affected by cropping system and management practice. Hortscience 39:1321-1325.
  • Ngouajio, M. and McGiffen, M.E., Jr. 2004. Sustainable vegetable production: Effects of cropping systems on weed and insect population dynamics. Acta Hort. 638:77-83.
  • McGiffen, Jr., M.E., Ngouajio, M., Crowley, D., Borneman, J. and Hutchinson, C.M. 2004. Soil organic amendments change low organic matter agroecosystems. Acta Hort. 638:249-254.
  • Ngouajio M., McGiffen, M. E., Jr. and Hutchinson, C. M. 2003. Effect of cover crop and management system on weed populations in lettuce. Crop Protection 22:57-64.
  • Hill, E.C. and Ngouajio M., 2004. Effect of hairy vetch (Vicia villosa) residue on weed species composition in pickling cucumber. Abstract North Central Weed Science Society meeting 14-16 Dec, Columbus Ohio.
  • Selvaraj, M. and Ngouajio, M., 2004 Effects of cover crops on soil microbial biomass in vegetable cropping systems. Hortscience 39:871.


Progress 01/01/03 to 12/31/03

Outputs
Our goal is to improve short vegetable rotations by integrating cover crops into the cropping system. Cucumber-tomato rotation was used as a model system. Five summer cover crops and three winter cover crops were combined in a factorial design to yield 15 different cropping systems. Preliminary results indicate that cover cropping improves the sustainability of vegetable systems by improving soil quality and fertility, and by enhancing weed suppression. A significant amount of biomass was produced by the different cover crops. Sorghum sudangrass produced the greatest amount of biomass with 10 t/ha when used in a summer fallow and 3 t/ha when planted immediately after cucumber harvest. Because of the large biomass produced, a sudangrass fallow may be an excellent system for soil building in a vegetable cropping system. Soil respiration, an indicator of microbial activity, increased in all systems with cover crops. Enhanced microbial activity is an indication of high quality soils. In terms of soil fertility, hairy vetch contributed over 30 kg/ha of nitrogen, sorghum sudangrass recycled 100 ppm of K, and rye recycled 60 ppm of P, when compared with the system with no cover crop. All systems with cover crops had fewer weeds than the bareground system. Up to 80% weed suppression was observed in systems where sorghum sudangrass or rye was the cover crop. These results suggest that cover crops may be used to supplement other control options in an integrated weed management system for vegetable production. Tomato growth was affected by both summer cover crops and winter cover crops. For the summer cover crops, tomato growth rate was highest with sudangrass, followed by cowpea, when the two cover crops were planted after cucumber harvest. This corresponds to the treatments that showed greatest weed suppression. Tomato plants in plots previously grown with rye grew faster than plants from the bare ground or hairy vetch plots. In conclusion, these results suggest that short vegetable rotations could be improved by integrating cover crops into the system.

Impacts
Most vegetable growers in Michigan recognize the benefits of long crop rotations. However, lack of good land (over 40% of the growers have less than 10 acres), and the global economy, have made long crop rotations difficult to practice. Integrating cover crops into current rotation systems will be more attractive to the 1,550 Michigan vegetable growers than any technology that proposes major changes in their production system. Legume cover crops such as hairy vetch can fix 50 pounds of nitrogen per acre. With a total of about 177,000 acres of vegetables in Michigan, this will correspond to 4,000 tons of nitrogen. This will result in significant savings to the industry and 4,000 fewer pounds of synthetic fertilizers applied in the field. The new cropping scheme will: 1) improve weed management and 2) protect the environment by reducing nutrient leaching after crop harvest and by reducing fertilizer inputs; 3) increase yield and sustainability by improving soil physical, chemical, and biological properties.

Publications

  • Selvaraj, M., Ngouajio, M., Warncke, D., Mutch, D. and Ernest, J. 2003. Integrating summer cover crops into cucumber/tomato rotation. HortScience 28:808. (Abstr.).
  • Ngouajio, M., Ernest, J. and Chase, W.R. 2003. Weed populations in cucumbers are affected by the previous cover crop. Weed Science Society of America Annual Meeting. February 10-13, 2003 Jacksonville, FL, p. 20. (Abstr.)


Progress 01/01/02 to 12/31/02

Outputs
In Michigan, cereal rye (Secale cereale) is a common cover crop used by many vegetable growers. It is a winter cover crop that is usually planted in the fall and plowed under in the spring prior to crop planting. Harvest of some pickling and slicing cucumbers planted early in the spring is completed by July 15 in a good year, allowing a short window to grow summer cover crops. Field experiments were conducted from 2001 to 2002 to study the effect of cover crops on weed populations in subsequent cucumbers. The experiment included one summer cover crop, two winter cover crops, and a system with no cover crop. Sudangrass (Sorghum vulgare) was the summer cover crop and was planted in July 2001 to simulate situations where a grower would like to grow a summer cover crop immediately after cucumber harvest. Ryegrass and hairy vetch (Vicia villosa) were the winter cover crops and were planted the first week of September 2001. Sudangrass was winterkilled in October 2001. In early May 2002, the winter cover crops or weeds in the summer cover crop plots were killed using two methods: cultivation or herbicide (glyphosate). Pickling cucumbers were planted the first week of June 2002. Each plot was divided into two subplots, one for yield (SPA) and the other for evaluation of weed populations (SPB). The SPA plots were kept weedfree by hand weeding and the SPB plots were kept weedy throughout the growing season. Plots were harvested in July 2002. Weed density and biomass were determined three times during the growing season using two 50- by 50-cm quadrats placed randomly in each SPB plot. The method of cover crop kill did not affect weed populations. However the cover crop species significantly affected weed populations. Plots previously grown with cover crops showed smaller weed density and biomass compare to the system with no cover crop. Weed densities were 10 to 80% lower in the cover crop plots. Sudangrass provided the greatest weed suppression among the cover crops studied. Sudangrass was followed by hairy vetch and ryegrass. These results suggest that both summer and winter cover crops can be used to supplement other control options for cucumber production under Michigan conditions.

Impacts
This is an interdisciplinary study on a system approach to vegetable production. The work combines crop rotation and new cover crop technologies to modify the agroecosystem and improve sustainability of the system. Michigan vegetable growers, and cucumbers growers in particular will benefit from the advantages of integrating new summer cover crops (sudangrass and cowpea) into their production system. The new cropping scheme will: 1) improve weed and disease management and 2) protect the environment by reducing nutrient leaching after crop harvest and by reducing fertilizer inputs; 3) increase yield and sustainability by improving soil physical, chemical, and biological properties.

Publications

  • Ngouajio, M. and McGiffen, M.E.Jr. 2002. Going organic changes weed population dynamics. HortTechnol. 12:590-596.