Mechanical thinner of apricot fruitlet

The aim of this study is to test this new thinner machine on apricots fruitlets, identifying the suitable working speed that best combine the most thinning effect in absence of visible damage of the branches and the remaining fruits. The machine is composed by a rotor equipped with radial rods on a central axe mounted in a rear tree point linkage of a tractor. Trials were carried out in March-May 2016 in an apricot orchard sited in Cesena (FC). The experimental was designed to compared mechanical thinning at different working speed (1.11 and 0.83 m/s) and hand thinning on green fruits (2 ≤ Ø ≤ 2.5 cm). The thinning effect was evaluated counting fruits remained from 40 branches randomized choice in upper and down part of four plants replicates. After the mechanical thinning, it was performed a manual thinning of finishing, aimed to eliminate the fruits too close together on the branch and, in general, ensure a uniform fruit set on the tree. Time required for thinning was measured in the trees mechanical thinned and compared with those one thinned only Handily (control). The two different working speeds gave two different thinning intensity: at 0.83 m/s fallen fruits were the 44 % of the total while at 1.11 m/s the 47 %. The thinning effects depends on branches length and at 1.11 m/s in branches of length over 35 cm was recorded the highest fruit reduction (50.3 %) and the lowest (44.4 %) in branches of length of less than 15 cm. Different were the results obtains in the thesis at 0.83 m/s in fact the percentage of fruit reduction was included between the 47.5 % of branch with a length greater than 35 cm and the 41.3 % of branches with a length of less 15 cm. Mechanical thinning can produce a net economic impact on apricot cultivation and in some cases, can replace the manual thinning and reduce considerable the labor costs.