Simulation and Quantitative Analysis of Branching Patterns of the Plum Tree

Abstract

Background and Aims: Pruning fruit tree is undoubtedly a critical cultural practice which leads to sustainable production along with profitability of the trees. Several limitations of classic approaches pertaining to studying pruning techniques based mostly on fruit yields and quality evaluations have kept us from thoroughly understanding the growth habits of branches under field conditions. A simulation model of branching patterns of the plum tree (Prunus salicina cv. Sanhua) introduced in this paper enables both non-professionals and professionals to better understand and predict pruning effects on branching pattern and fruiting habit of the trees. The visual comparison of branching and fruiting characteristic of the prunedparent shootprovides immediate feedback on different pruning intensities at the level of shoots.

Methods: Semi-Markov chains were built with diverse initial probabilities, transition probabilities and occupancy distributions to describe the number of occurrence of girl shoots along the pruned parent shoot. Branching structures were reconstructed using AmapSim computer software with different shoot types, considering topological and geometrical functions.

Key Results: The results demonstrated different branching zones in the pruned parent shoot were found in the same order. Moderate heading back and slight heading back parent shoots differed in short shoot position. Of all pruning intensities, the branching zone in severe heading back parent shoots was shorter than the sylleptic branching zone. The three-dimensional reconstruction images of pruned parent shoots displayed illustrative examples to elucidate proper pruning technique among three pruning intensities.

Conclusions: Severe heading back parent shoot had a strong branching capability. In comparison with moderate heading back, slight heading back parent shoot had a higher proportion of fruiting zones, therefore the latter is usually considered balancing vegetative and reproductive growth in the conventional pruning of plum trees.

The stochastic model could serve as a feasibility groundwork against which quantitative differences in branching structures of prune parent shoot under different pruning systems can be compared.