Here are my take home points, there is a lot there but for now this much to digest
Jackfruit propagation is still in its infancy, with most production based on seedling trees. In the Philippines, Malaysia, Thailand and Vietnam significant improvements have been made by the selection of clones and propagation via grafting. Common grafting techniques are approach, bud, chip, epicotyl and wedge grafting. In most cases grafting occurs on its own rootstock, thereby minimising compatibility issues. In this study we have examined the potential to use other species as rootstock, with two aims in mind. Firstly, the potential for disease resistance, with particular reference to Phytophthora palmivora and secondly the potential to decrease canopy vigour and improve fruit set.
Rootstock combination for grafting:The rootstock species markedly influenced the growth and performance of the jackfruit scion. The Kamansi (A. camansi) stock was incompatible and did not survive in the nursery and hence was not able to be included in the field planting. At one year after planting, jackfruit on its own scion was 154 cm high, followed by jackfruit on tipolo (A. blancoi) at 101 cm and jackfruit on marang (A. odoratissimus) at 74 cm.
There was a strong incompatibility between jackfruit and Tipolo (A. blancoi), less so with jackfruit on marang and excellent compatibility with Jackfruit on jackfruit. At four years after grafting the growth performance, yield and susceptibility to Phytophthora was influenced by the treatments. The jackfruit marang combination was shorter and had a smaller trunk size, with smaller canopy size with better production compared to jackfruit on its own stock.
Fruit production, although variable appears to be higher in the jackfruit-marang combination. The marang rootstock trees obtained zero infection after 4 years from field planting as compared with jackfruit rootstock (2 out of 4) which is already infected with canker on the collar, at the base of the tree near the soil line.
Comparison of Amber and Rajang varieties: Extensive sensory profiling work has been completed on both Australian grown jackfruit ‘Rajang’ and ‘Amber’ varieties.
‘Rajang’ Elicits a mid-strength aroma intensity with distinct notes of jammy and overripe banana, ‘Rajang’ has a sweet aroma with hints of orange lolly. A strong flavour is characterised by an overripe banana attribute and milder notes of artificial sweetness and orange lolly. ‘Rajang’ has medium firmness with a slight rubbery and fibrous texture, however, it is also juicy. The artificial sweet flavour lingers into the aftertaste which also has slight notes of green banana.
‘Amber’ Overall a milder fruit, ‘Amber’ has a mid-strength aroma intensity with slight hints of jammy and musty, overripe banana is the dominant aroma characteristic detected at low-medium intensity. Flavour intensity is medium to high, however, only low levels of the attributes orange lolly and artificial sweet were detected. ‘Amber’ is a very firm fruit, fibrous and rubbery, but like ‘Rajang’ it is still juicy. Despite the mild flavour, the aftertaste of ‘Amber’ is of medium intensity with a distinct green banana attribute.