I think there something different happening with jackfruit this year. I also noticed this on my neighbors tree that all the flowers are on the tips of small branches, not the main trunk. That tree is fruiting for the first time, so i thought may be it is a different variety but after couple of weeks our jackfruit trees also bloomed and they also had flowers on the top/slim branches, not on the main trunk. In the past this never happened with our trees, they always had flowers/fruits on the main trunk only, not even on big branches, just on main trunk. But this year it is completely opposite, nothing on main trunk and all on the tips of small branches. And, the quantity of flowers is not normal, they are too much all over the tree.
Also one more interesting thing is: normally there are 2 flowers on one branch tip, but this time there are 3 flowers on each branch tip. One is smooth and still not opened, two are hairy/dotted green and the interesting thing happened is one of the hairy/dotted flower turned black in few days time and the 2 other are still green.
Do you guys think may be it has something to do with the weather or something wrong going on in the atmosphere?