June fall
The Junifall (also: Junifruchtfall ) describes the fall of part of the fruit mainly from pome trees. Apple and pear trees in particular drop some of their fruit in the period from the end of May to the beginning of July, first three to four and then again about six to eight weeks after flowering. Both fruit fall periods can merge into one another. It is a natural process, brought about by competition for limited assimilates . In the case of cherries, the fruit fall is known as rubella .
root cause
The main reason for the fruit fall is a lack of or insufficient fertilization . The phenomenon occurs more intensely in years with cool and damp weather at the time of flowering. A cork layer forms at the base of the stalk of the affected fruit because the fruit is not adequately supplied with nutrients, the so-called abscission zone. The cause of corking is the plant hormone auxin , which the seeds of the fruit do not produce in sufficient quantities. For detachment ( abscission ), rows of small cells are created across the axis of the fruit stalk. By dissolving the cell walls it comes to a separation from the wood.
Importance for fruit growers
The June fall is not a problem for the producers of fruit , as it usually does not affect the harvest volume. On the contrary, the tree separates from over-developed fruit systems. Only 4–5% of the flowers produce fruits. There is also no need to thin out the fruits by hand ( cleaning , no longer common today), mechanically or with the help of plant treatment agents . In years without an increased fall in June, the artificial removal of fruits ensures that the remaining fruits are of sufficient quality. Without fall in June or thinning, the trees would produce too many small fruits that are not marketable. In the following year, this could even lead to a severe reduction in flowering and, as a result, the amount of fruit. This process is called alternation .
Importance for hobby gardeners
In the private use of fruit trees, clearing leads to improved fruit quality if it is done before the fall of June. One or two fruits are left on an inflorescence. The number of fruits can be related to the number of leaves: 10 to 15 leaves, counted in June, are enough for an apple. In shady areas of the tree, all fruit attachments should be removed. It is cleaned out a few weeks after flowering by hand or with scissors. This results in fewer fruits that are larger and have a higher quality overall.
literature
- Robert Schumacher: The fertility of the fruit trees. Ulmer 1989, 3rd edition, ISBN 3-8001-5274-6
- ↑ The fertility of the fruit trees. P. 89.
- ↑ The fertility of the fruit trees. P. 203.
- ↑ The fertility of the fruit trees. P. 87.
- ↑ The fertility of the fruit trees. P. 85.
- ↑ The fertility of the fruit trees. P. 144.
- ↑ The fertility of the fruit trees. P. 60.
Individual evidence
- ^ A b State Association for Fruit Growing, Garden and Landscape Baden-Württemberg eV (LOGL): Working calendar June 2005. In: Obst & Garten 6/2005. ( Fruit & Garden online , accessed February 24, 2011)
- ↑ a b Press release from the North Rhine-Westphalia Chamber of Agriculture from June 23, 2010: Now the apples are falling. ( Online ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , Accessed on February 24, 2011)
- ↑ Weihenstephan Information Service : Is the June fruit fall in apples predictable? ( Online ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. , Accessed on February 24, 2011)
- ↑ Organic farming in the Federal Agency for Agriculture and Food (BLE): fruit curtain regulation. ( Online ( Memento of the original from March 3, 2013 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this note. , Viewed on February 24, 2011)
