VIEW ARTICLE

Techniques

Comparison of Seed Priming Techniques with Regard to Seedling Emergence and Pythium Damping-Off in Sugar Beet. Charles M. Rush, Associate professor, Plant Pathology, The Texas A&M University System, Texas Agricultural Experiment Station, Bushland 79012; Phytopathology 81:878-882. Accepted for publication 15 February 1991. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/Phyto-81-878.

Three seed priming techniques were compared for their effects on earliness, rate, and uniformity of seedling emergence of sugar beet in infested and uninfested soils. Seed was osmoprimed with —1.5 MPa NaCl or —1.2 MPa PEG 8000, or solid-matrix-primed (SMP) with water and a hydrous silicate clay as the solid substrate. Washed and untreated seeds were included as controls. Seed was planted in soil infested with Pythium ultimum or in uninfested soil, and stand data were recorded for approximately 15 days. Three days after planting in uninfested soil, SMP- and NaCl-treated seed produced greater stands than the untreated control, and SMP-treated seed produced a greater stand and faster, more uniform emergence than all other treatments. Eight days after emergence, only the stand of the washed treatment was greater than the untreated control. Stands in all other treatments emerged at a faster rate than in the untreated control, and SMP induced faster emergence than any other treatment. In infested soil, primed seed also gave significantly better stands than washed or untreated seed 8 and 15 days after planting. Primed seed also had less preemergence damping-off, but there was no difference in postemergence damping-off. SMP was better than both osmoprimed treatments in promoting early emergence, suppressing preemergence damping-off, and in producing a greater final stand. SMP-treated seed still maintained a “primed condition” 7 mo after treatment.