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Die Bodenkultur - Journal for Land Management, Food and Environment
K.-U. HEYLAND and M.-E. MEER:
The significance of seedquality of wheat for the certainty of field emergence and the compensation of stress on seed and embryo influenced by coated or dressed nutritive or active substances
Different stresses during seed production and germination or emergence determine the future growth and development of a plant. To model these effects, different levels of loads were established by using kernels of wheat that had been subjected to defined mechanical impacts or were dressed or coated with varying amounts of nitrogen-fertilizer, growth regulators or fungicides. In addition the interaction with seed-size and plant population were determined. This research was conducted in 1984/85 until 1986/87 under laboratory and field conditions at the University of Bonn and other locations in the Federal Republic of Germany.
1. Growth retardation of seedings from smaller grains can be compensated to some extend by using fungicidal seed dressings or coatings.
2. Effects of mechanical load, as it can occur in a combine, will be reduced with larger seeds or with those, that are dressed with a combination of N-fertilizer plus fungicides plus a growth-regulator.
3. By using aprecision seed technique, a sowing density of 200 fungicid dressed kernels per squaremeter can make the same yield as the conventional density of 400 kernels per squaremeter.
4. Calculating the fungicide dose on a per kernel base results in a lower vitality with smaller grains compared to a dose per weight base.
5. A descriptive model was used to show the system interactions.
Key words: wheat, sowing technique, seed coating, stress, yield.