# Design and Evaluation of a Shaping and Pruning Machine for Dwarf and Densely Planted Jujube Trees
###### Abstract  
A shaping and pruning machine for jujube trees was developed in this study to address the difficulties of high intensity and low efficiency of artificial pruning for dwarf and densely planted jujube trees in Xinjiang. The key components of the machine were designed according to the growth information and pruning technical requirements of jujube trees. Additionally, the structural and working parameters of components or parts were determined. Then, utilizing the forward speed of the machine, cutter rotation speed, and cutter diameter as influencing variables, and the missed pruning rate and stubble breakage rate as evaluation indexes, a quadratic regression orthogonal test with three factors and three levels was constructed. Meanwhile, analyses of variance and response surface were conducted to establish mathematical regression models of influencing factors and evaluation indexes, and the influence of significant factors on response indexes was analyzed. The test results were optimized, and the optimal parameter combination was obtained as follows: the rotation speed of the cutter was 2300 r/ min, the diameter of the cutter was 250 mm, and the forward speed was 0.3 m/s. Then, field validation tests were conducted according to the optimal parameter combination. The results showed that the average values of the missed pruning rate and stubble breakage rate for the machine were 5.46% and 5.01%, respectively. The results indicated that the operation of the shaping and pruning machine met technical requirements for pruning jujube trees. This research contributes to rapid shaping and pruning operations in large-scale orchards of dwarf and densely planted jujube trees, which is conducive to promoting the whole mechanization management of jujube gardens in Xinjiang. agricultural machinery; jujube; shaping and pruning machine; test +
Footnote †: journal: Applied sciences  
simple auxiliary pruning tools. Commonly used auxiliary tools include manual, electric, pneumatic and hydraulic scissors [15; 16]. Among them, manual scissors have the shortcomings of labor intensity, low work efficiency and easily caused occupational diseases; Electric, pneumatic and hydraulic scissors need to be equipped with a power source, whose weight makes them unsuitable for manpower to operate for long periods [17; 18; 19]. Mechanical pruning mainly uses a pruning machine to conduct shaping and pruning on a large scale and in orchards with standardized planting patterns [20]. At present, the common pruning machines for fruit trees are composed of a pruning device, frame, power system and other key components [21; 22]. The design of a pruning machine involves the design of key components of the pruning device, including the design and selection of the structure and working parameters of the tool. According to the working mode, the commonly used pruning devices include reciprocating moving cutters and disc cutters [23; 24; 25]. Recently, many studies have been conducted on mechanized pruning equipment for horticultural plants or orchards at home and abroad [26; 27; 28]. In 1955, [PERSON] et al. in America developed a saw-disc pruning machine to reduce the cost of pruning citrus trees by hand [29]. Its pruning device was composed of 12 sets of disc cutters, which could achieve unilateral pruning of fruit trees with a pruning efficiency of 0.4 \(\mathrm{hm^{2}/h}\). However, this machine could prune one side of the trees, but could not complete the shaping and pruning of a single plant; the pruning form was single, and the adaptability was poor. Based on the growth characteristics of fruit trees such as grapes, apples and pears, [PERSON] et al. introduced the curtain pruning machine to cut upright growing branches, which improved the efficiency of pruning [30]. [PERSON] et al. in Italy designed a pruning machine for olive trees, which was mainly composed of a pruning device and crushing and recycling mechanism for residual branches.