Apple monitoring in Germany & the Netherlands: A whole systems approach to grower education & research

Abstract

Twenty one Jonagold orchards in three regions of Germany and one in The Netherlands were monitored during the 1989 season for a range of biological, economic and management factors. Most orchards were 8 years old on MIX stock. Tree numbers varied between 1250 - 3472/ha and the selected orchards covered single and double row planting as well as 4, 5 and 6 row beds. Flower numbers varied between 0.95m and 5.27m/ha but often orchards with high flower numbers set a lower percentage of fruit. Fruit set varied between 7.5 and 34.1 %. Average fruit number/tree varied between 105 and 330. Average fruit weight on an orchard basis varied between 140 and 280g. Highest extrapolated yield was 92.2t/ha and the lowest 19t/ha. Gross margins varied markedly between districts mainly because of average price. The highest gross margin recorded was DM 62,000 per ha and the lowest DM 9800. Harvesting and marketing costs represented about 20% of total returns but chemical costs were less significant in the range 3.0 - 3.3% of total returns. Market prices on average were highest in the south of Germany (DM 0.82/kg) and lowest in The Netherlands (DM 0.48/kg). Detailed appendices are included setting out individual grower's spray and fertiliser programmes and labour and machinery inputs. Data is recorded on a per tree basis with the trees divided into 3 levels. The harvest data includes yield, fruit size, fruit colour, and rejects. Some data is supplied on terminal and lateral positions of the flower buds and subsequent fruiting. Analyses is given of various relationships, such as fruit number versus fruit size, and reasons for differences identified. The paper provides a basis for further development of this monitoring work to allow growers to improve their profitability by making management changes. It also identifies areas of research which are still needed to allow reliable predictive and explanatory apple tree models to be developed.