Bearing Habit of Sapindus mukorossi and the Relationship between the Shoot Characteristics of the Parent and Bearing Shoots and Yield

Abstract

(1) Research Highlights: Sapindus mukorossi Gaertn has substantial economic and medicinal value as a high-quality raw material for energy, traditional Chinese medicine, and landscaping. However, few studies have focused on the bearing habit and shoot characteristics of S. mukorossi. (2) Background and Objectives: We aimed to investigate the bearing habit of “Yuanhua,” a selective breeding variety of S. mukorossi, and to identify the relationships among shoot characteristics, fruiting, and yield. (3) Materials and Methods: Ten healthy S. mukorossi trees were randomly selected to investigate the number of current-year shoots and bearing shoots. Eight-hundred-fifty current-year shoots of “Yuanhua” S. mukorossi were selected to investigate the number and position of the bearing and vegetative shoots. A total of 210 parent shoots and 145 bearing shoots of “Yuanhua” S. mukorossi were selected to investigate the characteristics. A generalized linear mixed model and a zero-inflated model were used for the analysis. (4) Results: (i) “Yuanhua” S. mukorossi has two types of current-year new shoots. After the new shoots produce leaves, if the growth points at the top continue to produce inflorescences that grow, bloom, and bear fruits, the new shoots are classified as bearing shoots. When the top growth points do not grow and do not produce inflorescences, the new shoots are termed vegetative shoots. The bearing shoots and vegetative shoots sprouted on the S. mukorossi parent shoots and developed into parent shoots in the following year, either developing from the bearing shoots or the vegetative shoots. (ii) The yield was affected by parent shoot characteristics. The type, length, diameter, and slenderness of parent shoots had significant effects on the number of current-year bearing shoots; the top diameter of the parent shoots and the number of current-year vegetative shoots had significant effects on parent shoot yield. (iii) The type of parent shoots, the length, and the top diameter of the current-year bearing shoots had significant effects on the single yield of a bearing shoot. (5) Conclusions: Selecting parent shoots with more bearing shoots and more fruit production according to the type, length, and thickness is a more efficient method for production management.