The automatic sapling grafting methods and grafting robot technologies are not comprehensively studied despite the fact that they are urgently required in practice. For this reason, a sapling grafting robot is developed to implement automatic grafting for saplings. The developed grafting robot includes clipping mechanism, moving mechanism, cutting mechanism, binding mechanism, and Arduino MCU based control system, which is capable of clipping, moving, positioning, cutting, grafting, and binding saplings. Experiments show that the stock cutting efficiency is 98.4%, the scion cutting efficiency is 98.9%, the grafting efficiency is 87.3%, and the binding efficiency is 68.9%. 1. Introduction Sapling grafting is an ancient technology that can assist breeding of good plant species, enhance their ability of anti-illness, improve the fruit quality, and strengthen their adaptabilities to harsh environments. The earliest literatures about manual citrus sapling grafting techniques appeared around 3000 years ago in China. Japan is the first country in the world that developed vegetable grafting robots. The first commercial model of a grafting robot (GR800 series, Iseki & Co. Ltd., Matsuyama, Japan) became available for cucurbits back in 1993 [1–3]. Since then, semiautomated or fully automated vegetable grafting robots have been invented by several agricultural machine companies, and several commercial models became available in East Asia, Europe, and more recently the U.S. [4–9]. However, grafting robots for saplings have not been comprehensively studied. A semiautomatic grape grafting robot was developed by CFCL in France to improve the grape production. Till present, the sapling grafting works are still following traditional manual methods in China, which are labour intensive but less productive. Besides, the grafted saplings often exhibit low survival rates and are less adaptive to the seasonal planting characteristics, which made it difficult to achieve industrialized sapling breeding production. Some similar literatures about sapling grafting robot could be found in China in the following areas. (1) Sapling Force Characteristics Experiments. Li et al. studied peach saplings and carried out experiments on peach force characteristics such as the cutting resistance force in vertical, traverse, and inclined cutting manners and also studied the variations of compressive injury forces [10]. Zhao et al. investigated poplar saplings based on a stick-to-stick grafting manner and studied the varying relationships between cutting resistance force and cutting depth, as
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