Publications

Below are links to the presentations from the 2024 Willamette Valley Vegetable Educational Program, held February 7 at the North Willamette Research and Education Center with sponsorship from Wilbur-Ellis. Check out what's new in vegetable production!

Delivered at the 2024 Willamette Valley Vegetable Educational Program. Nick Andrews presented on factors to consider in choosing cover crops and the work of the Western Cover Crops Council to develop an online tool to assist farmers in cover crop selection.

Delivered at the 2024 Willamette Valley Vegetable Educational Program. Dr. Navneet Kaur presented on symphylan control, including identifying them, sampling for them, and choosing crop rotations to reduce their populations.

Delivered at the 2024 Willamette Valley Vegetable Educational Program. Hannah Baker, a graduate student in Dr. Inga Zasada's USDA-ARS lab, presented on plant pathogenic nematodes and strategies for testing for and controlling them.

Delivered at the 2024 Willamette Valley Vegetable Educational Program. Dr. Kristie Buckland presented on managing seedcorn maggot (Delia platura) by adjusting planting dates. Seedcorn maggot can cause stand loss in corn, beans, parsnips, and other crops.

Delivered at the 2024 Willamette Valley Vegetable Educational Program. Dr. Steve Fennimore from the University of California, Davis presented on innovations in precision weeding tools and their ability to reduce hand weeding costs.

Delivered at the 2024 Willamette Valley Vegetable Educational Program. Dr. María I. Zamora Re presented on using the WSU Irrigation Scheduler app to manage irrigation for each particular field and crop.

Delivered at the 2024 Willamette Valley Vegetable Educational Program. Victoria Triolo and Hunter Walker from Wilbur Ellis presented on uses of insect biocontrols in integrated pest management and their research on applying them using a small UAS (drone).

Delivered at the 2024 Willamette Valley Vegetable Educational Program. Dr. Ocamb discussed similarities and differences of Fusarium and Rhizoctonia, the high Fusarium pressure in the valley, and promising work with biocontrols to manage Fusarium.

In 2023, the Blossom-End Rot Toolkit project was initiated.

Agenda and presenter slides from Spring 2023 Vegetable Grower Seminar (pdf files)

In 2022, the Oregon State University Dry Farming Project launched the Dry Farm Melon Production in Oregon project, funded by WSARE.

On February 1st, 2022, a tomato grafting workshop was held at the Oak Creek Center for Urban Horticulture.

In July 2021, we welcomed growers and vegetable breeders to tour our quinoa variety trial including low-saponin varieties. This handout summarizes results from our 2019 quinoa variety trial and the layout of this year's trial.

Resources from the Food and Drug Administration and Oregon Department of Agriculture to help growers comply with the FDA Food Safety Modernization Act (FSMA) Produce Safety Rules. Presented January 29, 2020 at the Northwestern Vegetable & Berry Farmers Conference

Slides from a presentation on how and why to use drip irrigation by Scott Lukas, of OSU's Hermiston Research and Extension Center. Presented January 29, 2020 at the Northwestern Vegetable & Berry Farmers Conference. Includes a case study on onions.

Slides from a presentation on insect pests and diseases observed on hemp by Scott Lukas of OSU's Hermiston Agricultural Reserach and Extension Center.

The goal of this project is to identify high-yielding, long storing and delicious kabocha, buttercup, and other winter squash varieties for production on Willamette Valley fresh market vegetable farms.

The market for organic vegetables is increasing. As conventional farmers transition fields to organics to meet this demand, there is a need for better organic nutrient management guidance, especially for nitrogen (N). Organic N management is more challenging than conventional N management due to a higher level of uncertainty surrounding the N supplying capacity of an organically managed soil as well as the constraints of organic fertilizers (supply, application timing and placement, and uncertainty of release rate and amount). As a result, conventional nutrient management strategies may not be appropriate for organically managed systems. With organic N management there is often a higher risk of excessive nitrate-N loss and higher risk of not achieving economic yield targets.

Several new powdered limestone products that are more finely ground (smaller particle size distribution) than products historically used have become commercially available. A major factor influencing the effectiveness of a liming material is its particle size distribution, with smaller particles reacting more quickly. Because lime efficiency estimates for various particle size fractions were established in the 1950’s, there is a need to evaluate current guidelines to determine if they adequately predict liming efficiency for these new products. The objective of this study was to assess the reactivity of commercially available powdered lime products (both calcitic and dolomitic) and various particle size fractions over a year with the goal of evaluating current OSU lime guidelines.

This year, we commemorate 20 years of OSU’s VegNet (1996-2016). VegNet has become a well-known and utilized resource for processed vegetable growers, researchers, and Ag professionals throughout Oregon. This regional program provides weekly activity reports for common broccoli, cauliflower, sweet corn, and snap bean pests. The main goal of the program is to serve as an early warning and detection network, to inform growers of potential pest outbreaks that may warrant increased field scouting and action. Notable trends from 2016 include extensive Cabbage Looper pressure, a continued increase of Cucumber Beetle species (12-spot and striped), and new Armyworms to be aware of. It is becoming apparent that pest activity can vary widely between field sites. Although the regional average is useful, it should not be the only metric used when considering if and how to treat for pests.

Experiments in Corvallis, OR and Pasco, WA evaluated the potential of bicyclopyrone, tolpyralate, halosulfuron and EPTC for weed control in carrots. Bicyclopyrone and tolpyralate significantly reduced plant stand, injured carrots, and reduced yield at all three rates. Only bicyclopyrone at 0.875 oz/A and tolpyralate at 1 oz/A provided yield within range of linuron, prometryn, and EPTC treatments. The prometryn treatment yielded the most carrots, followed closely by linuron and EPTC. Halosulfuron killed all carrots. Weed control with bicyclopyrone and tolpyralate was similar when comparing within treatments with equal carrot injury. A possible exception was that tolpyralate may have controlled crabgrass better than bicyclopyrone. Prometryn control of hairy nightshade lasted longer than linuron.

Oregon vegetable processors are in need of improvements to the cost of harvesting broccoli and cauliflower, along with improvements to the quality of the vegetables being processed. The objectiveof this research project is to develop autonomous, mechanical harvesting solutions for the broccoli and cauliflower producer. This work is complementary to Oregon State University development of a new broccoli hybrid developed specifically for automated mechanical harvest.

The resistance to white mold obtained so far in snap beans has been derived from NY 6020, which provides partial physiological resistance. Under light disease pressure, plants will show few if any symptoms, while under heavy pressure, the plants may show a moderate level of infection (whereas susceptible BBL types will be 100% molded). Cultivars with this form of resistance would not need any supplemental control with fungicides, whereas under heavy pressure, fungicides might be required, but at a reduced frequency or quantity. The objective of this study was to determine whether OR6771 would benefit from an integrated mold control approach that included fungicides typically used in snap production, Topsin M and Rovral tankmixed.

Processors need broccoli with better quality traits than what is available in cultivars developed for California and Mexico fresh markets. Farmers need to reduce labor costs of broccoli production by mechanizing harvest. Most contemporary commercially available cultivars are not suitable for either mechanical harvest or processing. The objective of the OSU broccoli breeding program is to develop broccoli varieties adapted to western Oregon with suitable quality and high yields. The program operates on a one year cycle where cuttings from the field are taken into the greenhouse in the fall where they are rooted and hand crossed and self-pollinated to produce seed for the next generation. Seed is harvested in May and June and used to plant trials for fall evaluation.

Authors: Alex Stone and Jenny Wetzel, OSU Horticulture

This handout summarizes the results from clubroot resistant brassica (cabbage, broccoli, cauliflower, Napa cabbage, etc) variety trials conducted in 2015-16 on farms in the Willamette Valley of Oregon as well as in greenhouse screening trials.

The resistance to white mold obtained so far in snap beans has been derived from NY 6020, which provides partial physiological resistance. Under light disease pressure, plants will show few if any symptoms, while under heavy pressure, the plants may show a moderate level of infection (whereas susceptible BBL types will be 100% molded). Cultivars with this form of resistance would not need any supplemental control with fungicides, whereas under heavy pressure, fungicides might be required, but at a reduced frequency or quantity. The objective of this study was to determine whether OR6771 would benefit from an integrated mold control approach that included fungicides typically used in snap production, Topsin M and Rovral tankmixed.

Processors need broccoli with better quality traits than what is available in cultivars developed for California and Mexico fresh markets. Farmers need to reduce labor costs of broccoli production by mechanizing harvest. Most contemporary commercially available cultivars are not suitable for either mechanical harvest or processing. The objective of the OSU broccoli breeding program is to develop broccoli varieties adapted to western Oregon with suitable quality and high yields. The program operates on a one year cycle where cuttings from the field are taken into the greenhouse in the fall where they are rooted and hand crossed and self-pollinated to produce seed for the next generation. Seed is harvested in May and June and used to plant trials for fall evaluation. In 2015, nine experimental hybrids were planted in a replicated yield trial, which also included two commercial check hybrids and a new exserted commercial hybrid from Seminis.

Oregon is the second largest producer of processed green beans, and cultivars are needed that are adapted to western Oregon. The types that have traditionally been used are the bush blue lake (BBL) green beans with high yields, excellent processing quality. On the other hand, then need improvement in plant architecture, disease resistance (especially to white mold), and are genetically isolated from other green beans. The primary objective of the OSU green bean breeding program is to develop high yielding and high quality BBL green beans with high levels of white mold resistance. In 2015, a yield and processing trial of 18 advanced lines was conducted. An additional commercial trial with 27 entries was also grown and evaluated. Seven advanced lines are undergoing intense scrutiny for release as the first partially white mold resistant lines commercially available.

Prices paid for sweet corn are low relative to the cost of producing the crop, and every strategy possible must be used to maximize net return. Two strategies used to enhance profitability but that have received little research attention under Western Oregon conditions are the use of pop-up fertilizers and increased plant populations. Despite indications that popup fertilizers improve early-season growth, concrete evidence that these fertilizers ultimately enhance growth and yield are often lacking. Seeding density also can be increased to improve crop yield up to a point, but intraspecific competitive ability and the competitive stress tolerance of varieties currently produced in the Willamette Valley has not been demonstrated.

This project is evaluating interseeding of crop crops to improve cover crop establishment after late harvested crops such as sweet corn and processing squash. In Project 1 at the OSU Vegetable Research Farm, a cover crop of oat and crimson clover produced the most cover crop biomass when interseeded at V4 compared to V6 and V8 plantings but may have reduced corn yield slightly because of competition for water or nutrients. Applying Laudis herbicide immediately after interseeding of the cover crop had no impact on cover crop establishment, even when seeds were broadcast on the soil surface and incorporated lightly. Clover did not emerge well in interseeded plots, possibly because it was planted too deeply. Clover establishment was best when seed was broadcast on the soil surface and incorporated with shallow tillage. Cover crop biomass in mid-December averaged less in interseeded plots than in fall-planted plots because the oat cover crops began to senesce.

Oregon State University’s VegNet is a regional pest monitoring program that provides activity reports for 10 common insect pests that affect broccoli, cabbage, cauliflower, sweet corn, and snap beans. Crop pests are sampled weekly and raw data is compared to activity trends from previous years. Regional pest monitoring helps growers and agricultural field representatives adjust their scouting effort when an outbreak is detected, and the combination of area-wide monitoring plus field-specific scouting reduces risk of crop loss. Reports are available on www.oregonvegetables.com, and sent via an email newsletter that currently serves over 400 subscribers. In 2015, increases in pest pressure were noted for black cutworm, spotted cucumber beetle, cabbage white butterfly, bertha armyworm, and diamondback moth.

The overall objective of this three-year project was to provide farmers with updated fertilizer recommendations for snap beans. The goal was to maximize nutrient use efficiency without compromising bean yield and quality. This was accomplished by partnering with commercial bean growers to conduct on-farm research as well as conducting trials at OSU’s Vegetable Research Farm.

The goals of this project were to determine 1) if liming controls clubroot, 2) the pH that must be attained to achieve commercially viable levels of control, and 3) how best to lime (materials, timing, incorporation strategies) to achieve that pH. Research conducted in 2014 showed that liming clubroot infected soils to a pH ≥7.1 is an effective practice for reducing both the incidence and severity of clubroot. Liming does not kill the pathogen but rather prevents disease spores from infecting the plant. In 2015 the research was focused on the relationship between disease incidence and severity when pH <7.1,better understanding when to apply lime, and how to incorporate to maximize pH change.

Urea is a common nitrogen fertilizer for sweet corn production. This two year project evaluated commercially available urea additives for their potential to provide crop production and environmental benefits. Specifically, experiments were designed to evaluate the efficacy of urea fertilizer products containing a urease inhibitor (Agrotain Ultra), or nitrification inhibitors, or a polymer coated urea product (ESN). Products containing nitrification inhibitors (SuperU and Instinct) were evaluated only in 2014, and found to have efficacy similar to ESN in slowing conversion of urea to leachable nitrate-N. The control treatment in all studies was granular urea without additives.

In recent years, several new powdered limestone products that are more finely ground (smaller particle size distribution) than products historically used have become commercially available. A major factor that influences the effectiveness of a liming material is its particle size distribution, with smaller particles reacting more quickly. Because lime efficiency estimates for various particle size fractions were established in the 1950’s, there is a need to evaluate current guidelines to determine if they adequately predict liming efficiency for these new products. The objective of this study was to assess the reactivity of commercially available powdered lime products (both calcitic and dolomitic) and various particle size fractions over a year with the goal of evaluating current OSU lime guidelines.

The updated rules are: 

Despite the availability of several herbicides in table beets, weed control is still problematic. UpBeet (triflusulfuron; DuPont) was recently labeled, but the labeled timings and rate are inadequate for optimum weed control, particularly for lambsquarters. An experiment was placed at the OSU Vegetable Research Farm to determine the tolerance of 2-leaf table beets to UpBeet when applied at double the currently labeled rate of 0.5 oz/A, and to beets at the cotyledon stage at 0.5 oz/A.

Report to the Oregon Processed Vegetable CommissionOregon is the second largest producer of processed green beans, and cultivars are needed that are adapted to western Oregon. The types that have traditionally been used are the bush blue lake (BBL) green beans with high yields, excellent processing quality. On the other hand, then need improvement in plant architecture, disease resistance (especially to white mold), and are genetically isolated from other green beans. The primary objective of the OSU green bean breeding program is to develop high yielding and high quality BBL green beans with high levels of white mold resistance.

For the past 18 years, processed vegetable growers in the Willamette Valley, OR have had a vital partner in crop pest monitoring – Oregon State University’s VegNet. This regional pest monitoring program provides weekly activity reports for common broccoli, cauliflower, sweet corn, and snap bean pests. Data is published on www.oregonvegetables.com and is available as an email subscription newsletter. The main goal of the program is to provide an early warning to growers of potential outbreaks that may warrant increased field scouting and action.

Prices paid for sweet corn are low relative to the cost of producing the crop, and every strategy possible must be used to maximize net return. Two strategies used to enhance profitability but that have received little research attention under Western Oregon conditions are the use of pop-up fertilizers and increased plant populations. Despite indications that popup fertilizers improve early-season growth, concrete evidence that these fertilizers ultimately enhance growth and yield are often lacking. Seeding density also can be increased to improve crop yield up to a point, but intraspecific competitive ability and the competitive stress tolerance of varieties currently produced in the Willamette Valley are poorly understood.

Processors need broccoli with better quality traits than what is available in cultivars developed for California and Mexico fresh markets. Farmers need to reduce labor costs of broccoli production but mechanizing harvest. Most contemporary commercially available cultivars are not suitable for either mechanical harvest or processing. The objective of the OSU broccoli breeding program is to develop broccoli varieties adapted to western Oregon with suitable quality and high yields. The program operates on a one year cycle where cuttings from the field are taken into the greenhouse in the fall where they are rooted and hand crossed and self-pollinated to produce seed for the next generation. Seed is harvested in May and June and used to plant trials for fall evaluation.

This research has demonstrated that liming clubroot infected soils to a pH ≥7.1 is an effective practice for reducing both the incidence and severity of clubroot. Liming does not kill the pathogen but rather prevents disease spores from infecting the plant. This research demonstrated that highly reactive calcitic lime products could be substituted for hydrated lime as they effectively raise the pH of the soil to the target pH of ≥7.1 within a week after application. The project also demonstrated that boron and Serenade drenches did not suppress clubroot under field conditions.

Enhanced efficiency fertilizer (EEF) technologies have the potential to improve the crop N use efficiency (NUE) as well as minimize negative environmental losses compared to conventional fertilizers. The EEF fertilizer products consist of urea plus additives (to inhibit N loss). The major pathways for N loss in our sweet corn cropping systems are 1) N leached below the root zone as water soluble nitrate-N (NO3-N), and 2) gaseous ammonia loss (NH3-N) to the atmosphere following a surface urea application.Field studies and a laboratory incubation study were conducted in 2014 to evaluate the potential for benefit from EEF products via reduced nitrate-N leaching. Three products were evaluated: ESN (polymer coated urea), SuperU (prilled urea containing both a urease and nitrification inhibitor), and Instinct (urea + nitrification inhibitor).

The overall objective of this multi-year project is to maximize nutrient use efficiency without compromising bean yield and quality. This year’s project objectives were to: 1) evaluate crop response to P fertilizer at current soil P test levels in grower fields; 2) generate phosphorus (P) potassium (K), and nitrogen (N) nutrient budgets (fertilizer inputs vs. harvest removal); and 3) evaluate relationships among bean root rot disease, plant P uptake, biomass allocation (pods vs. leaves).

It is difficult to find information on winter squash production and storage. This page aggregates resources relevant to Oregon winter squash growers.

Alex Stone is fixing broken links and adding new content in January 2021 - come back soon!