| 1. |
- Schmitt, A., et al.
(author)
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Evaluation of non-chemical seed treatment methods for the control of Phoma valerianellae on lamb’s lettuce seeds
- 2009
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In: Journal of Plant Diseases and Protection. - 1861-3829. ; 116:5, s. 200-207
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Journal article (peer-reviewed)abstract
- The aim of the present study was to identify seed treatment methods for eradicating Phoma valerianellae from lamb’s lettuce seeds in organic vegetable production. Using seeds naturally infested with the pathogen, the effect of three physical methods (hot water, aerated steam, electron treatment) and different agents of natural origin (micro-organisms, plant derived products, resistance inducers) was tested on moist filter paper, in seed trays under controlled conditions and in the field. in an initial screening, none of the tested putative resistance inducers prevented infection by P. valerianellae, while two out of seven formulated micro-organism preparations and six out of 16 experimental microbial strains were effective. When selected agents and the three physical seed treatment methods were compared in blotter and seed tray tests, the physical methods were generally the most effective treatments, while the micro-organism treatments were clearly less efficacious. However, in field experiments with the same seed lots and the same treatments, a statistically significant increase in plant stand was not obtained with any of the treatments. Combinations of the three physical treatment methods with selected non-chemical agents did not perform better than the physical treatments alone. The most effective alternative seed treatments identified in the present study, aerated steam, hot water, electron treatment and thyme oil (0.1%), can be recommended for eradication of P. valerianellae from lamb’s lettuce seeds in organic farming. Because their efficacy was generally as high as that of the chemical fungicide Aatiram (active ingredient thiram), they are also potentially suited for use in conventional vegetable production.
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| 2. |
- Koch, Eckhard, et al.
(author)
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Evaluation of non-chemical seed treatment methods for the control of Alternaria dauci and A. radicina on carrot seeds
- 2010
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In: European journal of plant pathology. - : Springer Science and Business Media LLC. - 0929-1873 .- 1573-8469. ; 127:1, s. 99-112
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Journal article (peer-reviewed)abstract
- The current study was initiated to evaluate the efficacy of physical methods (hot water, aerated steam, electron treatment) and agents of natural origin (resistance inducers, plant derived products, micro-organisms) as seed treatments of carrots for control of Alternaria dauci and A. radicina. Control of both Alternaria species by seed treatment with the resistance inducers was generally poor. Results were also not satisfactory with most of the formulated commercial micro-organism preparations. Based on the average of five field trials, one of these, BA 2552 (Pseudomonas chlororaphis), provided a low but significant increase in plant stand. Among the experimental micro-organisms, the best results were obtained with Pseudomonas sp. strain MF 416 and Clonostachys rosea strain IK726. A similar level of efficacy was provided by seed treatment with an emulsion (1%) of thyme oil in water. Good and consistent control was generally achieved with the physical methods aerated steam, hot water and electron treatment. Aerated steam treatment was, apart from the thiram-containing chemical standard, the best single treatment, and its performance may at least partially be due to extensive pre-testing, resulting in dosages optimally adapted to the respective seed lot. In some of the experiments the effect of the hot water treatment, which was tested at a fixed, not specifically adapted dosage, was significantly improved when combined with a Pseudomonas sp. MF 416 or C. rosea IK726 treatment. The results are discussed in relation to the outcome of experiments in which the same seed treatment methods and agents were tested in other seed-borne vegetable pathosystems.
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