The next generation of orchards has to be built in the orchards of Brandenburg. The problem here is the existing growth and yield depressions in the rebuilding: A major portion of the plantings will have to be done on areas in which one or two generations of apple trees previously grew. Finding suitable areas on asparagus farms on which no asparagus has been grown is becoming increasingly difficult.
Depression of growth and yield in replicas can be up to 60% (on average 13%) compared to “unpolluted” soil, depending on the soil conditions and the choice of asparagus variety. In the case of apples, yield declines of 30-50% (47% on average) were determined. It is known from observations near Apfel in Brandenburg that the effects are stronger on the sandy areas of the fields than on loamy areas. The previously used chemical soil treatment is no longer permitted in Germany.
Extensive research has been carried out for many years on the causes of the replication problem (specific soil fatigue – specific apple or asparagus replant disease) and the possible cause is still not fully understood. A causal complex is assumed that is largely microbial in nature, including:
- Fungal pathogens (Fusarium spp., Rhizoctonia, etc.)
- Oomycetes (Phytium, Phytophtora)
- Formation of autotoxins and allelochemicals
- Bacteria (actinomycetes, Pseudomonas spec.)
Within the scope of the proposed EIP project, variants of cultivation management and alternative soil treatment to reduce the damage to permanent crops for Brandenburg soil and climatic conditions are to be tested in practice in order to create the conditions for a transfer of the results to the region. The plant cultivation framework for the replica will be optimized. This applies to the preparation of the soil in terms of structure, humus content and nutrient ratios, as well as planting distances and fertility options. The strength and severity of the expected growth depressions as well as the effectiveness of soil treatments are verified in container tests.
The aim of the project is to use suitable cultivation strategies to increase the yield of apple and asparagus in the cultivation under Brandenburg soil and climate conditions. This should be done by examining the cultivation strategies in the farm areas that have been described as potentially successful in studies. Furthermore, the effectiveness of the cultivation strategies should be assessed by comparing the achieved increases in yield with the necessary additional costs, taking into account yield modeling for the years following the project. For companies with apple and asparagus cultivation in Brandenburg, the changeover to more successful reproduction or cultivation strategies can mean the possibility of further production without space restrictions. As a result, higher investments may sometimes be required for the new area, but operational continuity is guaranteed.