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2007 Research Presentations and
Posters Oral Presentations:
Seed Moisture
Determination: Principles and Procedures
Sabry Elias, Oregon
State University Seed Laboratory
ABSTRACT The purpose of the new Seed Moisture Determination: Principles and Procedures Handbook is to address this need and provide background regarding the factors internal and external to the seed that influence its moisture content. The relationship between seed moisture content and relative humidity, temperature, and seed chemical composition are discussed. Both primary and secondary moisture testing methods are described. The primary air-oven method and the secondary electronic moisture meter method and their procedures are presented as standardized tests for seed moisture for many crops. Both methods have been calibrated against other primary methods for many crops and they are proven to achieve reliable, consistent and reproducible results. Air-oven procedures for species not listed in Table 5 of the handbook are also provided. For each method, the following parameters are described: equipment, sampling and sub-sample size, sample preparation (e.g., grinding and cutting), drying procedures and moisture determination, number of replications per test, species suitable for each method, and proper calculation of moisture content on both fresh- and dry-weight bases. Two suggested secondary methods, microwave oven and near-infrared, are described but require further research before being considered standardized. Techniques for applying tolerances and reporting seed moisture results are presented as well as potential sources of errors in test results. This Handbook provides the first detailed protocols for seed moisture testing to be incorporated into the AOSA Rules for Testing Seeds. The Handbook is dedicated to Dr. Don Grabe, Professor Emeritus at Oregon State University, for his outstanding service and contributions to seed moisture testing. He served as the Chair of the ISTA Seed Moisture Committee from 1980 to 1992. Dr Grabe first reported many of the results provided in Table 5 in this handbook and described the strengths and limitations of various seed moisture methods.
Development of Standard
Blowing Procedure for Tall Fescue
Abstract The results showed that regardless of the amount of light-weight inert in a sample, varieties, and years; the optimum separation point occurred at the same air velocity value, a condition which is critical to develop a blowing point that is applicable for all samples of this species. The germination of the blowings compared to the heavy pure seeds further confirmed the visual observations. The number of germinable seeds found in the blowing portion of tall fescue samples was less than 1% of the 2500 seeds, the total purity sample size. This indicates that blowing discards a negligible number of germinable florets. In contrast, the average germination of the pure seed portion was (93.4%). Likewise, the great majority of multiple florets that were blown out did not contain caryopsis and their average germination was only 2.5%; whereas the majority of multiples that remained in the pure seed cup contained caryopsis and had average germination of 63%. These results suggest that both single and multiple florets blown out should be considered inert and those remaining in the heavy portion should be considered pure seeds. Comparable results across blowers and laboratories were obtained regardless of whether the sample contains high or low levels of light-weight inert material. Two principles make it possible to achieve and repeat such uniform results: 1) the use of a uniform master calibration sample to determine the optimum blowing point for all blowers; and 2) the use of equivalent air velocity value to reproduce the blowing point to test samples. These results strongly suggest that using a small but uniform number of “master” calibration samples to calibrate all blowers achieves consistent results across blowers. The inert matter content separated by the current and the proposed blowing method was similar (within statistical tolerance). Furthermore, a time saving above 50% was achieved using the new proposed method. The new method would have several benefits including 1) time saving; 2) producing consistent test results in seed laboratories; 3) reducing discrepancies in test results between producing and receiving states; and 4) providing a useful tool for seed cleaners to monitor their cleaning level and achieve desired cleaning standards.
Evaluation of
Noxious-Weed Tolerances
ABSTRACT Re-evaluation to the current AOSA Table 8 Noxious-weed tolerances is needed as it does not have an identifiable reference source and the formula used to calculate the tolerances is in error (Miles, 1963; Dodge and Canfield, 1972, and Elias et. at., 2000). These facts call into question the validity of Table 8 for regulatory use. In an attempt to locate the source of Table 8 it was discovered that although AOSA Table 8 is similar to Table F3 in the "Handbook of Tolerances", Miles, 1963, the two tables are not the same. The most obvious difference is that Table F3 (Miles 1963) shows accept and reject values, whereas Table 8 (AOSA Rules) shows applicable tolerances. Based on this information Elias et al. (2000, Seed Technology 22:5-14) proposed an alternative to the current AOSA Table 8. Table 1 of this paper is based on appropriate statistical procedure using the cumulative distribution function of the Poisson distribution with the SAS Program. The statistical construct for Table 1 (Elias, et al. 2000) is based on Table 7 of Person and Hartley, 1966, but with the advent of computers, it provides more accurate and precise tolerances by computing the accumulated probabilities under the Poison distribution. The tolerances in Table 1 (Elias, et al. 2000) are slightly narrower than the current AOSA Table 8; for example, if the number of noxious weed seeds labeled or represented in a sample is"10", the current tolerance in Table 8 is “17”, and in the tolerance in Table 1, Elias, et al., 2000 is “14”. Not only does Table 1 (Elias, et al. 2000) address regulatory concerns of introduction and spread of noxious weeds and the cost of weed control, it also provides a sound statistical basis for noxious weed seed regulatory tolerances. Posters:
Alternative Method for
Coated Onion Treated with Pesticides
ABSTRACT
Germination of
Echinacea Species Is Enhanced by Ethylene
ABSTRACT
Electronic Data Transfer
for Seed Testing Laboratories
ABSTRACT The software components developed at Mid-West Seed Services, Inc. include Sample Track®, Sample Track® Local, and v-Worksheet®. Applications are built on the .Net Framework and use Microsoft databases for storage. Sample Track® runs on a Microsoft Access database and employs web technologies (email and web services) to submit samples. Sample Track® Local utilizes a Microsoft SQL Server 2000 backend for data storage and bar code scanners as its primary input method. v-Worksheet® uses a Microsoft SQL Server 2000 backend, bar code scanners for sample test identification, and Tablet PCs as its primary input method. The test results web site is built on both ASP 3.0 and ASP.NET; other reporting solutions utilize Microsoft Reporting Services. Utilizing Mid-West Seed Services v-Worksheet® software along with Tablet PC technology, seed technologists are able to input data electronically. Bar-code identification tags provide an accurate method of identifying samples reducing the need to manually input identification numbers. The software computes all calculations and averages according to ISTA rules and regulations with the ability to automate printing of authentic ISTA certificates. This efficient and virtually error free data input process streamlines a laboratory’s overall process. Mid-West Seed Services’ Sample Track® software provides laboratories a way to retrieve client’s sample information in an electronic format, greatly reducing potential error rate present when entering a customer’s identification information. *Presenting author |
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