Osmoconditioning of Beet Seeds to Improve Emergence and Yield in Cold Soil1

Abstract

AbstractTable beet (Beta vulgaris L.) seeds are characteristically slow germinating, and have a large time spread of germination. These characteristics interfere with the early establishment of a uniform, vigorous stand of seedlings in cold wet soil. This study was undertaken to determine if osmoconditioning (OC) of table beet seeds in polyethylene glycol 6000 (PEG) and MgSO4 solutions and/or other measures would improve germination and/or reduce germination time and thereby improve emergence, seedling establishment and yield. Seed balls of ‘Ruby Queen’ and ‘Cardenal’ were osmoconditioned in −1.2 and −1.18 MPa solutions of PEG and MgSO4, respectively. Treatments were performed at 15 °C for 7 days in the light. The benefits of OC were not lost by drying back the seeds. Aeration during OC followed by a 2 min rinse with water was the most effective treatment in improving germination or emergence in laboratory and growth chamber studies. In the 1980 field trial, OC in PEG improved the rate of emergence by 2 to 3 days, the stand by 40% and the root, top, and total yield by 40, 66, and 59%, respectively. In 1982, seedling emergence was biphasic. The first phase lasted 23 days and showed large differences in rate of emergence and stand between osmotically treated and untreated seeds and resembled the 1980 emergence pattern. The second phase commenced after a 30 mm rain with a resurgence of emergence in all treatments. The resurgence rate was highest in untreated seeds and this reduced the treatment differences in stand and yield. The resurgence was attributed to invigoration of the non‐germinated seed by low soil water potential (drought). Several MgSO4‐OC treatments increased the number of roots but decreased root size.