Poor stands are a constraint on organic peanut production because stand losses of 50% or more are possible with untreated seed. Biological, other novel seed treatments, and soil amendments were tested for efficacy against pre- and post-emergence damping-off in greenhouse, microplot, and field plot trials. Seed of the lines Perry, GP-NC 343, and N03081T were utilized in all trials. Nine treatments were tested in natural soil in the greenhouse. Treatments included Bacillus subtilis (Kodiak), B. pumilus (Yield Shield), Trichoderma harzianum (T-22 PB and Plantshield HC), Muscodor albus, Coniothyrium minitans (Contans), activated charcoal, two separate soil amendments of dried herbage of Monarda didyma cultivars, a commercial fungicide check (Vitavax PC), and an untreated control. Vitavax PC and Kodiak were the only seed treatments with higher percentage emergence and survival than untreated seed. A separate greenhouse experiment was conducted for seed treatments using natural soil or soil infested with field isolates of Aspergillus niger. Seed were treated with Kodiak, copper hydroxide (Champion), Plantshield HC, Kodiak and Plantshield HC combined, Streptomyces griseoviridis (Mycostop), hot water, Vitavax PC, or were left untreated. Seedling emergence and survival was much lower in inoculated versus uninoculated plots. In all plots, treatment with Kodiak increased percentage emergence and survival compared to untreated seed, but was not as effective as Vitavax PC. In uninfested plots, treatment with Champion also increased emergence and survival compared to the untreated check. Field microplot studies in Clayton, NC evaluated seed treated with Kodiak, T. harzianum, activated charcoal, Vitavax PC, or untreated seed on the three peanut lines following wheat, oat, or triticale cover crops, soil amendment with M. albus, or no cover as a control. In both years, the percentage emergence and survival was highest for Perry seeds treated with Vitavax PC. Cover crops did not affect emergence, but M. albus treatment suppressed emergence. In field studies at Lewiston, NC, the three peanut lines were treated with M. albus, Kodiak, T. harzianum, or were untreated. In the 2007 trial, none of the treatments improved stands compared to the untreated check. In 2008, the highest stand counts were produced by seed treated with Kodiak. In both years, the largest stands were N03081T. The most commonly observed pathogen was A. niger. Confounding effects of seed line and seed source prevent assessment of performance from individual cultivars. However, regardless of seed line, in most trials Kodiak seed treatment consistently increased emergence and survival over untreated seed.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-10312008-133746 |
| Date | 07 November 2008 |
| Creators | Ruark, Sarah Johnson |
| Contributors | Barbara Shew, D. Michael Benson, Chris Reburg-Horton |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-10312008-133746/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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