In the context of the harvest due to the different maturity and size to improve the fruit quality a coordinated multiple picking of the plantations is done. The apples are placed directly from the tree in the large harvest boxes, as it is harvested mainly without a ladder due to the currently dominant tree height. In general, the bulk bins are placed on low trailers, which are coupled together to a plucking train. To conserve the soil, wide-base tires are on the tractor.
The optimum harvest times for different varieties of apple orchards are determined by the Fruit Growing Research Group. At representative sites in the region the so-called starch-iodine test is performed and the sugar content and fruit firmness is determined.
With the iodine test there is the possibility to determine the state of the ripening process. All you have to do is cut an apple and dip the pulp into the iodine solution. After a few minutes, the result can be read.
Wherever the pulp contains starch (sugar in the preliminary stage), it changes color. The darker the discoloration the more immature the apples. One can distinguish between different intensity values. When one speaks of the strength value of 1, the flesh is discolored completely dark and no fructose is incurred. At starch level 3, for example, clear bright spots in the flesh can be seen. Here is fructose has already occurred. A very ripe and therefore the best for the end user to enjoy the apple is the starch value 6. At this stage the apple no longer has starch anymore, but just fructose.
The degree of the sugar concentration in the apple can be detected with the refractormeter. For this juice is pressed out of an apple and a few drops of the juice are sprinkled on the prism of the refractometer. Then the prism flap is closed. By looking into the refractometer, the practitioner can read the sugar content of the fruit pulp on the scale with a white / blue border.
Especially the end of the ideal harvest date may be determined by the penetrometer. The penetrometer measures the resistance of the flesh per unit area. To perform a measurement, a piece of the skin (the higher firmness could distort the measurement) is removed and the stamp of the penetrometer is pressed at this point into the fruit. The value at which the stamp is entering the fruit, can be read directly on the indicator scale. The display is usually calibrated in kilograms per square centimeter.
Depending on the degree of maturity the planning for the early sale or storage in refrigeration and CA / ULO storage facilities is to be decided.