Productivity is negatively related to shoot growth across five mango cultivars in the seasonally wet-dry tropics of northern Australia

Introduction: Mango productivity is low in seasonally wet-dry tropical areas where breeding programs require information on factors affecting productivity of mango cultivars. Specifically, our study tested a novel hypothesis that, among Australian- and Florida-bred cultivars, the greater growth of vegetatively vigorous cultivars would contribute to lower levels of fruit production in comparison with less vegetatively vigorous cultivars, in a wet-dry tropical environment.

Materials and methods: A field experiment was conducted on trees of the cultivars ‘Kensington Pride’ and ‘Strawberry’, both polyembryonic cultivars, and ‘Haden’, ‘Irwin’ and ‘Tommy Atkins’, all monoembryonic cultivars.

Results: Shoot growth was recorded over two years; in both years the polyembryonic cultivars produced more new shoot length than the monoembryonic cultivars; ‘Irwin’ was the least vigorous cultivar in both years. Across cultivars, there was a negative relationship between normalised (by flowering intensity and canopy area) fruit number or yield and vegetative vigour as represented by new shoot length.

Conclusion: The results supported the hypothesis that the greater shoot growth of vegetatively vigorous cultivars contributed to lower levels of fruit production in comparison with less vegetatively vigorous cultivars in a tropical environment. This is the first study which demonstrates that the extent of seasonal shoot growth had a fruit production cost for mango.