Challenges for developing high-density mango orchards

High-density planting has become a standard for modern orchards for most of the temperate fruits trees. This system requires technical expertise and aims at better utilization of resources (light, land, labor) and better efficiency of cultivation practices, leading to higher yield and profitability. Mango is a tropical fruit species with generally low average yield. Increasing planting density could be a lever to improve mango yield, but it is still at an experimental stage. The mango tree is naturally large and moving to medium or high planting density would be a challenge in order to control tree size while maintaining good tree production. The objective of this paper is to discuss this challenge based on the existing knowledge on mango tree growth and reproduction, and on some original results. The core of the system is the interactions between vegetative growth, which defines tree growth, and reproduction, which defines tree production. Vegetative growth can have positive or negative effects on reproduction, and reproduction has generally a negative effect on vegetative growth. Vegetative growth, reproduction and their interactions depend on the cultivar and the rootstock, suggesting that the plant material is a key factor in the success of increasing the planting density in mango orchards. Vegetative growth, reproduction and their interactions are also affected by environmental conditions and by cultivation practices, in particular pruning and training. As a whole, the results highlight the need for a holistic approach to design medium- or high-density mango orchards and to analyze the failures and successes of the experiments. This holistic approach should also consider the mango crop protection in order to develop agroecological orchards requiring less phytosanitary inputs.