Gruber


Die Bodenkultur - Journal for Land Management, Food and Environment

S. Gruber, K. Emrich and W. Claupein:

Managing the soil seed bank of oilseed rape by tillage and genotype selection – a survey of three project years

Summary

The study aimed at strategies for managing the soil seed bank of oilseed rape and minimizing gene dispersal by transgenic volunteers. Three-year results and well-combined approaches were evaluated in one overall approach. Varieties differed in dormancy from 8–46 % in the laboratory. Corresponding field experiments showed that low-dormancy genotypes established a smaller soil seed bank than high-dormancy genotypes. 7–9 % of seeds from harvesting losses entered the soil seed bank after immediate stubble tillage. This number was below 0.6 % when the soil was temporarily or always untilled. Therefore, low-dormant genotypes should be grown in combination with appropriate soil tillage.
The data allow individual risk calculations on farm level since the reference value „seed loss” can be easily determined by farmers. Scenario calculations for risk assessment studies can be well supported by the data.

Key words:  Volunteer oilseed rape, Brassica napus, dormancy, seed bank, gene dispersal, soil tillage.