1a.Objectives (from AD-416):
1. determine recolonization potential of P. penetrans in broadcast vs. bed fumigated fields;
2. quantify the impact of fumigation treatments and P. penetrans on red raspberry establishment, and;
3. promote implementation of fumigant alternatives through field days, grower meetings, web-based decision-making tools, and printed materials.
1b.Approach (from AD-416):
We will identify 4-6 fields located in northern Washington raspberry fields and establish replicated plots comparing broadcast fumigation to bed fumigation. In these plots plant-parasitic nematode population densities, plant establishment and plant growth will be monitored over a multiple year period. In collaboration with WSU extension, written and web-based materials will be created and disseminated that help raspberry growers navigate the new EPA fumigation requirements.
Red raspberries are a major crop in the Pacific Northwest with a farmgate value of over $64 million. The root lesion nematode, Pratylenchus penetrans, is a significant pest of raspberry that causes reduced plant establishment and decline in yield. Currently, red raspberry growers do not have adequate information to make informed decisions regarding alternative, reduced chemical nematode management practices. This two-year project is striving to begin to close these knowledge gaps and provide red raspberry growers with information so they can make informed nematode management decisions. To this end, during year two of this project five field experiments, which were established in the previous year to determine the recolonization potential of P. penetrans into fumigated areas as well as the impact of fumigation and the nematode on raspberry establishment were monitored. In these trials a comparison was made between the industry standard of fumigating the entire field (broadcast) vs. fumigating only the areas where raspberries would be planted (bed); the advantage of bed fumigation is that much less product is used. One year after planting, P. penetrans population densities were similar or lower in bed fumigated areas compared to broadcast fumigated areas. Bed fumigation also supported similar establishment of raspberry compared to broadcast fumigated plots. In addition, to promote the implementation of alternative nematode management practices two grower field days were held to present research results and promote the implementation of bed fumigation by growers. A web-based tool is still in the development stage; this too will assist growers in choosing alternative, reduced chemical nematode management practices.
This research was conducted in support of objective 308 1A: Development of New Technologies for Alternatives and Integration into Commercial Crop Production Systems Currently Dependent upon Methyl Bromide Soil Fumigation.