Amaranth Seedling Emergence as Affected by Seeding Depth and Temperature on a Thermogradient Plate1
- D. M. Webb,
- C. W. Smith and
- J. Schulz-Schaeffer2
Seedling emergence studies are normally conducted in growth chambers, greenhouses, or field plots and require much space, equipment, and time when several factors are considered. Amaranth (Amaranthus spp.) is a new crop in the United States that often exhibits inadequate field emergence because of environmental constraints. Two seedlots, one white seeded and one black seeded, from the same population of Amaranthus hypochondriacus L. were assessed for emergence index and percentage emergence in a peat-sand medium over a range of temperatures and seeding depths using a modified thermogradient plate. Seed color produced no difference in emergence, but significant differences in emergence were caused by temperature, seeding depth, and temperature × depth interaction. A predictive response surface shows expected amaranth seedling emergence index at temperatures between 15 and 42°C and seeding depths between 13 and 51 mm. Highest amaranth emergence index and percentage emergence on the thermogradient plate occurred from the 13-mm seeding depth and at temperatures between 24 and 34°C; these data suggest field emergence may be satisfactory with soil temperatures between 18.5 and 24°C.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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