The effect of fruit thinning and tree pruning on tree starch reserves and on fruit retention of "Sensation" mango trees.
Davie S. J., Stassen P. J. C.
Author Affiliation: Institute for Tropical and Subtropical Crops, Nelspruit, South Africa.
: 160-166
Abstract : Mango cv. Sensation trees set large numbers of fruits which remain on the tree to an advanced stage. If a tree with a large crop is left unmanaged, more fruits than necessary will be abscised, and yields will be reduced to levels which the tree can support. While excess fruits remain on the tree, carbohydrate stores are depleted, which reduces the size of the remaining fruits. Two methods of thinning fruit load were investigated prior to the expected time of natural abscission of 17-year-old trees at Nelspruit, South Africa. These methods were thinning by hand in November to numbers which the trees could naturally be expected to nurture to maturity (~50%) by removing the smallest fruits, or by pruning away all one-year-old growth of every other branch in November. The reserve carbohydrates in these trees were compared with those of controls, which were left to abscise naturally, and with trees where the complete fruit load was removed at the time the fruits on the test trees were thinned. Thinning fruits in November reduced further fruit fall and increased the size of the remaining fruits. Pruning back half of the branches was more advantageous than hand thinning. It is suggested that fruit thinning should have been carried out earlier to reduce the depletion of carbohydrate reserves.