Willamette Valley

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.

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.