Optimizing crop loading of apples and pears - results 2004-2006 (foliar fertilizers, thinning)

摘要

Main topics of the research-project FuE 03OE088 of "Bundesprogramm Okologischer Landbau" (30.04.2004-31.12.2006) were the testing of foliar fertilizers in organic apples and pears, optimizing lime sulphur for blossom thinning, looking for alternativesto lime sulphur for blossom thinning and looking at different combinations of thinning measures. Only the results of testing foliar fertilizers (carried out by KoGa Ahrweiler and OVB/OON Jork) and combinations of thinning measures (carried out by LVWO Weinsberg) are described in this article. Over three years only a small increase in yield was evaluated for the fertilizers Aminosol PS and Wuxal Ascofol (site Ahrweiler, apple variety 'Elstar'). In Jork (apple variety 'Holsteiner Cox') yield could only be judged in 2005 and 2006. Wuxal Ascofol showed some advantage in comparison to the control. At pear variety 'Conference' no clear tendencies could be seen, the control had the highest yield. In 2005 the fruit-setting of 'Conference' was very low becauseof bad conditions during blossom. All combinations, which consisted of two thinning measures, balanced the crop loading of 'Elstar' (organic orchard near LVWO Weinsberg) in a way, that in spring 2007 the setting of blossom clusters was clearly higher than in the control, so alternate bearing could be reduced. The best effects had thinning strategies, that included blossom thinning (2 x 30 I/ha lime sulphur). Less time was necessary for thinning by hand, when additional pruning was done (169 h/ha thinning by hand - only by hand 255 h/ha) or when blossom spraying was performed (101 h/ha left for thinning by hand).