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Row Crops


215 – California Berry Crops: Improving Water Efficiency

Principal Investigator: Dr. Ramiro Lobo, Small Farms and Agricultural Economics Advisor, UC Cooperative Extension. For more project information, click here.

Escalating water prices and prolonged drought conditions throughout various regions of the state have forced specialty crop growers to re-assess their irrigation practices and determine if they can reduce their water use in the production of blueberries, blackberries and strawberries without sacrificing yields and quality. The near and long term effects of decreased water availability will alter the way berry crops are grown; farming practices will need to be modified to use water more efficiently, with concomitant adjustments for salinity and nitrogen management. This project will assess the effects of reduced irrigation on yield, normal growth parameters, postharvest quality and profitability of strawberries, blueberries, and blackberries through replicated trials in the Central Coast region, Sothern San Joaquin Valley and Southern California. We use a randomized complete block design with 4 replications and 5 irrigation treatments, varying from 80% to 120% of ET for strawberries and 25% to 125% of ET for blueberries and blackberries. Postharvest assessment measures include nutritional content, shelf-life, flavor, texture and consumer preferences. We revise existing cost and returns studies to assess the potential impact of reduced irrigation levels on crop profitability. We disseminate our findings through field days / workshops and published reports. Our UC Davis and UC Cooperative Extension team include horticulturalists, irrigation specialists, postharvest physiologists, and agricultural economists with extensive specialty crops experience.

243 - Role of Abiotic Stress in Development & Management of Macrophomina Charcoal Rot of Strawberry

Principal Investigator: Dr. Alex Putman, Assistant Specialist in Cooperative Extension and Assistant Plant Pathologist, Plant Pathology and Microbiology Department, University of California Riverside. For more project information click here.

Macrophomina phaseolina causes Macrophomina charcoal rot of strawberry, the fourth most valuable crop produced in California. It occurs in every major and minor strawberry production region in California, and preplant fumigation is currently the only commercially acceptable management practice to combat this disease. In other crops, expression of charcoal rot symptoms is often associated with drought or heat stress. However, the influence of abiotic stress in development of charcoal rot in strawberry has not been elucidated. Our objective in this project is to determine the relationship between drought stress and the development of charcoal rot of strawberry. To do this, we will establish a field study to evaluate three irrigation treatments (low, optimal, high) following the CropManage irrigation scheduling system. Irrigation treatments will be evaluated in a factorial treatment arrangement with two cultivars and two inoculum treatments. Disease incidence and severity will be assessed visually and by isolation of plant samples, and drought stress will be assessed with soil water potential probes. Findings from this study will provide us with new insights on the disease cycle of Macrophomina charcoal rot of strawberry that can be used to develop improved management strategies or breed less susceptible cultivars.

Nematode Management

31 – Experimental Nematicides

Principal Investigator: Dr. Becky Westerdahl, Department of Nematology, University of California – Davis. For more project information, click here.

Current control methodology for root-knot nematode relies on the use of Metam sodium and Telone II. Metam sodium, for example, was used on 33% of California’s carrot acreage in 1997 and Telone II was used on 10%. The potential for loss of the standard chemical nematicides due to various environmental concerns is great enough to warrant a continued search for alternatives. Each year, a number of “promising” candidates are promoted by various sources. These include chemical nematicides, and what are termed natural or novel products or soil amendments. Even though many of these may not prove to be efficacious, demonstrating this by comparison to a standard nematicide treatment provides valuable justification for maintaining current registrations. Such a process succeeds in sorting out those that do truly have potential for nematode management such as the Valent (formerly Abbott Laboratories) “biological nematicide” DiTera which has recently obtained California registration.

65 – Nematode Control

Principal Investigator: Dr. Philip Roberts, Department of Nematology, University of California – Riverside. For more project information, click here.

The project site is infested with three distinct populations of root-knot nematode, two of Meloidogyne incognita and one M. javanica. We will continue to use the site to identify, characterize and breed host plant resistance to root-knot nematodes into a series of advanced breeding lines and varieties of susceptible field and vegetable crops, especially cowpea (blackeye beans) and carrot, and possibly large and baby Lima beans.  The site is used comparatively with other infested sites at field stations in the San Joaquin Valley (KREC) and Coachella Valley (UCR-CVARS). The research is part of a focused effort to develop nematode resistant commercial varieties suitable for California, thus providing alternatives to soil fumigation for nematode management.  We are evaluating different breeding populations, genetic stocks, and germplasm lines of blackeye beans and carrots with and without nematode resistance genes, in plots with different nematode population levels. These experiments provide assessment of the relative value of several resistance genes in each crop for protecting against nematode infection and promoting yield. The research is conducted in cooperation with breeding programs from the industry, USDA, and UC, and it is a long-term effort necessitated by cycles of screening, selection, and re-screening and selection as resistant materials are identified and advanced. The project site is an important resource in development of nematode resistant crops and their effective deployment in annual crop systems for California and elsewhere.

104 – Alternatives to Nematicides

Principal Investigator: Dr. J. Ole Becker, Department of Nematology, University of California – Riverside. For more project information, click here.

For more than half a century, methyl bromide (MBr) alone or in combination with chloropicrin has provided growers of high value crops with a very effective tool to control plant pathogens, parasitic nematodes and weeds. The US ban of MBr dictates a major production change that requires the evaluation of alternative methods and pesticides. Furthermore, many organophosphate and carbamate pesticides that include all of the currently California registered non-fumigant nematicides will be severely restricted or even taken off the market as a consequence of the Food Quality Protection Act. This project is designed to evaluate new nematicides and crop production strategies for management of plant-parasitic nematodes. 

114 – Biology and Management of Sugar Beet Cyst Nematode

Principal Investigator: Dr. Edward Caswell-Chen, Department of Nematology, University of California – Davis. For more project information, click here.

In 1987, plant-parasitic nematodes were estimated to cause a 12.3% reduction in yields of the world's major crops, and a 10% reduction in sugar beet yields.  The cyst nematodes are considered the third most important group of plant-parasitic nematodes in the world. Heterodera schachtii, the sugar beet cyst nematode (SBCN), is the most important nematode pathogen of sugar beets, and it occurs in areas where sugar beet and cole crops are grown.  Our research addresses this species.  Estimated sugar beet losses attributed to SBCN range from 1 - 70%. SBCN is a serious pathogen of sugar beets and cole crops (broccoli, Brussels sprouts, cabbage, cauliflower, kale, rape, rutabagas, spinach, and turnip).

Nematodes are often managed by nematicides. "Sustainable'' or "alternative'' agricultural systems need to be developed which will integrate naturally occurring beneficial interactions to manage nematodes.  Achieving successful integrated management will depend on combinations of tactics including, resistant cultivars, and crop rotations, each providing a limited level of population suppression. 

Research objectives cover several different aspects of sugar beet cyst nematode (SBCN) management including experiments to assess: the damage threshold of SBCN on sugar beets and cole crops growing in sandy-loam soil in southern California, the relationship of the damage threshold to planting date and soil temperature, nematode population dynamics relative to planting date and temperatures, and evaluation of chemical and non-chemical methods of control. 

240 -Establishing a Field Site for Research on Root-knot Nematode Management in Vegetables

Principal Investigator: Dr. Antoon Ploeg, Associate Nematologist and Associate Cooperative Extension Nematologist, Department of Nematology, University of California Riverside

Co-Principal Investigator: Dr. Ole Becker, Cooperative Extension Specialist & Nematologist, Department of Nematology, University of California Riverside

During the initial year of this project we will establish nematode infestation on a new field site at the station, by inoculating root-knot nematodes (M. incognita race 3) into this new field site. Inoculation will be done through pumping nematode eggs into buried drip tubing. As the host crop, cherry tomato will be cultivated. After this initial inoculation, roots of the tomatoes will be examined and soil samples will be collected to determine distribution and levels of nematode infestation at the end of this first crop. In the second year, we will again grow a nematode susceptible crop (eg green bean) over the entire field to further build up and evenly distribute nematode levels, so the field is ready for trial use in the third year. Trials on this site will be to evaluate strategies for nematode management and control, and may include testing of novel nematicides, rootstocks, biological control agents or their derivatives, resistant crop cultivars, biofumigation, anaerobic soil disinfestation, etc.


174 – Cover Cropping to Manage Pests in Vegetable Production

Principal Investigator: Dr. Antoon Ploeg, Department of Nematology, University of California – Riverside. For more project information, click here.

Suppression of pests and pathogens has often been highlighted as a valuable “byproduct” resulting from a high degree of biodiversity. However, current agriculture practices (e.g. monocropping, increased use of external inputs) have caused a decline in biodiversity. When pest control and other ecosystem services previously contributable to biodiversity are lost, the economic and environmental costs can be significant. Cover crops are non-cash crops that are typically grown during the off-season for their indirect beneficial effects. In agricultural systems, cover crops may aid in the control of insects, pathogens or weeds. Societal demand for environmentally friendly crop production has increased the demand for pest suppressive cover crops. Although cover crops have been shown to reduce plant damage caused by weeds, nematodes, and insects an integrated approach for using cover crops to manage pests is lacking. Vegetables are attacked by insects, disease, and nematodes which significantly reduce yield and quality. Weeds compete with vegetables further reducing yield. Cover crops may directly affect pests, and also enhance beneficial organisms.

The study proposed here would address the lack of an integrated approach to evaluate the effect of cover. The results from this study will provide data that ultimately will lead to lessening the reliance on synthetic pesticides, particularly on soil fumigants. The latter group of pesticides are being targeted for restrictions because they are the main contributors to the emission of volatile organic compounds (VOC) a serious threat to air quality.


241 - Chia Breeding and Sunflower Heliotropism

Principal Investigator: Dr. Hagop Atamian, Assistant Professor, Schmid College of Science and Technology; Biological Sciences, Chapman University, Orange

Salvia hispanica (commonly known as chia) is gaining popularity as a healthy oil and food supplement for humans and animals worldwide. This is mainly due to its high polyunsaturated fatty acid (PUFA) and low saturated fatty acid (SFA) oil content, in addition to high protein, fiber and antioxidant levels. Due to its recent popularity, no breeding efforts have yet been directed towards improving the currently cultivated varieties. The long term goal of this project is to create a genetic linkage map that would speed up future breeding efforts in Salvia hispanica through the use of marker assisted selection (MAS). Sunflower is a robust solar tracker. During the day, it continuously orients its apex from east to west. Interestingly, at night sunflower gradually reorients towards east in anticipation of the sunrise. Previous work demonstrated that heliotropism in sunflower 1) increases plant growth by enabling them to better adapt to changing environment 2) is mediated by differential growth rate on the opposite sides of the stem which is regulated by the plant circadian clock. The goal of this project is to conduct physiological experiments to understand the mechanisms by which the circadian clock differentially regulates growth within different parts of a single organ (in this case the stem).