Canopy management for improving productivity in litchi
Wider spacing, lack of scientific methods of training, pruning, canopy architecture and nutrient management are considered as major attributes assigning to low productivity in litchi. Under natural conditions, the plant grows vigorously and fruiting area gradually shifts to the upper peripheral region which makes it difficult for fruits to harvest. Besides producing less quality fruits, the shade cast by vigorous trees lowers the harnessing efficiency of solar radiation indispensable for photosynthesis. The litchi tree has the tendency to bear fruits on outer surface of the canopy receiving maximum solar light and economical yield is confined to two-third of the lower middle canopy. Fruiting in litchi with quality fruits can be obtained by opening of the centre portion of the tree and facilitating more light penetration inside the tree canopy. Fruit development in litchi is also sensitive to light conditions. Therefore, being a very crucial component of productivity, crown structure and canopy size in litchi is of paramount significance. Apart from the other secondary factors (related to site and cultural practices), canopy architecture management of a tree is dependent on its flushing behaviour, carbohydrate budgeting, plant spacing and planting system. Well-designed canopy architecture is vital to control tree growth pattern, tree shape and maintain high quality fruit production. Generally, space apportionment is maintained at 60:30:10% for skeleton, fruiting and aeration zone. A large canopy surface area well exposed to sunlight is desirable, since it increases light interception and trapping of solar energy. Well-formed canopies permit better aeration and sunlight exposure to foliage and fruits, improve the photosynthetic efficiency, fruit bud differentiation, ripening and fruit quality and reduce microclimate buildup for pests and disease. Light distribution within tree canopies depends on various inter-related factors. The intrinsic architectural pattern of the cultivar itself and planting system which includes both tree arrangement in the orchard and training of the tree canopy through different approaches plays a vital role in influencing light interception. Manipulations of tree architecture through the training system and pruning strategies also affect light interception which in turn influence photosynthesis and transpiration at the fruiting branch and whole tree level.
Nath, V., Marboh, E.S. and Gupta, A.K. (2020). Canopy management for improving productivity in litchi. Acta Hortic. 1293, 129-142
light interception, training system, high density planting