Evaluation of ethanol preconditioning as a rapid seed vigour and viability test

It is essential that tests for evaluating seed vigour be faster and increasingly efficient to enable precise differentiation among batches. In this way, it is possible to evaluate the quality of seeds based on the anaerobic metabolism of cells when exposed to environments lacking oxygen. Thus, the objective of this study was to establish methodology for evaluating the viability and vigour of 3 lots of cowpea (Amendoim cultivar) seeds using the ethanol test. The treatments were carried out in a completely randomized design with four replications. For the test, 25 seeds were stored in hermetically sealed PET (Polyethylene the Ethylene) bottles containing 40 ml of distilled water and subjected to 3 soaking times in distilled water (6, 24, and 48 h) at a controlled temperature of 40°C in a germinator. The amount of ethanol produced was quantified with the aid of an adapted breath analyser. The results are expressed as mg L-1; these data were then compared with data for the following: germination; the first germination count; the total length, root length and shoot length of the seedling; dry weight of the seedling; emergence in the field; emergence speed index; and electrical conductivity. The experimental design was completely randomised, and the data were subjected to analysis of variance and correlation analysis. The results were compared using the Tukey test at 5% probability. Measurement of ethanol after 6 or 48 h of soaking at 40°C was effective for determining the viability and vigour of cowpea seeds. As ethanol test results have high correlation with germination and vigour test results, this approach is a viable alternative for analysts and seed producers.