Forming oval crowns for mechanical plum harvesting.
In large orchards, plums intended for preserves can be shaken off mechanically. The plum harvester has a grapple frame that collects fruit, which covers the trunk in height 80 cm from the ground. Hence, the lower branches should grow at a distance of approx 1 m from the ground, so that you can freely place the frame under the crown. The branches should grow in a row or diagonal to that line, so that you can easily grab them with a vibrator. This arrangement of branches gives the crown of an oval shape. The crown should consist of 6-8 branches (Lynx.).
Lynx. Plums for mechanical harvesting must have a trunk of a meter and only 6-8 branches in the crown.
The greater number of limbs makes it difficult to operate the vibrator.
Shaping plums for mechanical harvesting is not difficult. The trees in the orchard have to be cut in height 120 cm from the ground. If they have branches, remove them. The branches are rarely above 1 m - hence only the guide remains after the cut. In the course of summer, a few shoots will emerge from the upper buds, giving a crown at the desired height 1 m from the ground. If the shoots have grown a lot, then in the spring of the next year we will thin them, leaving only these, that follow the order of the row. 3–4 shoots should be left. If little shoots have grown, that is, 2-4 you have to leave them all: direct to the row by bending and tying them with strings. The guide should be shortened to 0,5 m above the side shoots.
In the third year, we form the second tier of boughs consisting of 2 to 4 shoots, allowing the handler to continue, free growth (Lynx.).
Lynx. When forming the crown for the mechanical harvesting of fruit, we leave only after 3-4 shoots in two whorls.
The formed crowns should be cut in a similar way to almost natural crowns. After finishing shaping, try to keep the oval shape of the crowns by cutting the branches from the inter-row side. The bases of the branches should be free of small twigs, so that you can grasp them freely with a vibrator.