Topworking mango trees.
Snyman J. C.
Author Affiliation: Tuinbouproefplaas, Instituut vir Tropiese & Subtropiese Gewasse, Posbus 295, Messina 0900, South Africa.
Yearbook - South African Mango Growers' Association 13 : 63-66
Abstract : A trial was conducted to establish whether (1) grafting directly onto pruned branches would be successful as opposed to grafting onto new vegetative growth; (2) whether pruned trees would benefit from painting with a sunburn protectant; and (3) whether partial topworking onto one-third or half of the tree would have any beneficial effect on yield. An orchard of 12-year-old cv. Haden trees, originally grafted on cv. Peach rootstocks, was used for the trial. Grafting directly onto the freshly-pruned wood resulted in an unacceptably low success rate of 22% and graft unions were weak. Grafting onto newly grown shoots resulted in a take of 88-96%. When trees were left without a breather branch (sap drawer), at the time of cut-back (i.e. all branches sawn off), and were painted with diluted or undiluted exterior PVA paint this resulted in 50% mortality and 33% of the remaining trees growing poorly. Of the similar trees which were painted with lime wash, 17% died and 33% produced very few or no new shoots. Trees with a breather branch retained at cut-back, receiving the same treatment were not adversely affected. None of the untreated control trees died but damage by sunscorch was clearly visible. Topworking one-third or half of a tree gave very poor graft success (as low as 16%).