Influence of amount of water in the paper towel on standard germination tests.

The standard germination test is the one test that is being widely used by every seed testing laboratory to check the viability of seeds. However, signifi cant variations in results exist between laboratories. The objective of this study was to evaluate the effect of various amounts of moisture in the paper towel on standard germination test results. Germination of various varieties and lots of hybrid sorghum (Sorghum bicolor L. Monech) and hybrid corn (Zea mays L.) seeds were evaluated us ing water at 2, 2.5, and 3 times the weight of paper towel. In all cases, the lowest amount of water gave maximum germination and as the water in creased in the medium germination decreased. In sorghum, the decrease in germination at the 2.5 moisture level was 1 to 6 % and at the 3, 5 to 9 %. In corn, this effect was more dramatic. Germination reduction at 2.5 level was 0 to 27 % and at 3, 6 to 35 %. Additional index words: Sorghum bicolor L. Monech, Zea mays L., viabili ty, variation, moisture. Introduction The seed industry and farmers cannot afford to gamble with huge in vestments on cheap, untested seed that may not germinate. Conversely, which is equally or more important, they cannot take a loss of good seed because of lower values obtained by incorrect testing procedures or inter pretation from the part of the analysts. The standard germination test is the one test that is being used widely by every seed testing laboratory to check the viability of seeds. In spite of this, it is disappointing to note that significant variations in results exist between laboratories. For example, the 1980 vigor 'referee' test for soybean, Glycine max L., and hybrid corn indicated significant variations among laboratories (8). In soybean, germinations ranged from 72 to 95% for one lot and from 76 to 93% for another. In corn, it varied from 77 to 91 % for one lot and from 72 to 92% for another. The 1980-81 midwest region AOSA-SCST joint referee on soybean germination revealed that about 50% of the tests were out of tolerance for at least one of the three samples tested (4). Similar results have been obtained, year after year, in other referee tests (2, 5). Director of Research, Production and Quality Control, Ag-ONE Seeds, 648 Miami Trace Rd. SW., Washington C. H., Ohio 43160 82 This content downloaded from 157.55.39.211 on Tue, 09 Aug 2016 05:52:28 UTC All use subject to http://about.jstor.org/terms VOLUME 5, NUMBER 2, 1980 83 There has been numerous 'refereed' tests on germination using various recommended temperatures. For example, during 1980-81 the SCST southern region conducted a soybean referee using 25 C VS 20-30 C and found no difference between the two methods (3). Rigdon and McDonald (6) also reported similar results on soybeans. Rules for Testing Seeds (1) suggests for most kinds of seeds blotters or other substrate should not be so wet that by pressing, a film of water forms around the finger. However, this is not specific enough to help the analysts in deciding the actual amount of water to be added to the substrate to get maximum germination. Tao (7) in his studies on soybean germination observed an increase in the number of ruptured seedlings with increased moisture of the paper towel. The objective of this study was to evaluate the effect of various amounts of moisture in the paper towel on standard germination test results. Materials and Methods Nine lots of 'NS-212' and 2 lots of 'GSA-2340' hybrid corn grown during 1979 in Illinois and 4 lots of 'GSA-1757' and 1 lot of 'Growers-30F' hybrid sorghum grown during 1979 at Plainview, Texas were used in this study. Table 1. Germination test results of hybrid corn obtained from two laboratories. Variety & Std. germ. Difference Tolerance Cold ■ lot # Lab 1 Lab-2 (From 'Rules') La'