Nursery Soil Fumigation and Outplant Performance

Most bareroot reforestation nurseries in the Pacific Northwest use soil fumigation to maximize size and quality of seedlings and minimize disease. Root disease is hard to quantify at an operational level, and fumigation effects on seedling field performance are uncertain. We conducted three nursery trials that included standard methyl bromide + chloropicrin (MBC) and nonfumigated (control) treatments and evaluated subsequent performance either in the woods or in large containers. Despite differences in nursery culling rates, survival did not differ in the two studies in the woods. Initial size differences at planting persisted, however, with seedling stem volumes 37 and 45 percent greater for MBC compared with control seedlings for the 2009 and 2010 outplanting studies, respectively. In the third trial, potted seedlings were placed in two moisture regimes (high and low) with high (control) or low (MBC) levels of root pathogens. Survival did not differ after one growing season. Both moisture and pathogens influenced seedling morphology during the study. High pathogen treatments continued to have significantly higher levels of root pathogens at the end of the first growing season regardless of moisture regime and likely played a role in reducing first-season shoot and root volumes. This paper was presented at the Joint annual meeting of the Western Forestry and Conservation Nursery Association and the Pacific Northwest Reforestation Council (Corvallis, OR, October 11–12, 2017).

Download this file:

Download this file

Details

Author(s): Nabil Khadduri

Publication: Tree Planters' Notes - Volume 61, Number 2 (2018)

Event: Joint Annual Meeting of the Western Forestry and Conservation Nursery Association and the Pacific Northwest Reforestation Council
2017 - Corvallis, OR

Volume: 61

Number: 2