From what I’ve read and what I’ve observed, chempedak (Artocarpus integer) has a high mortality rate when grown from seed. I suspect that they die due to the stem growing faster than what the roots can support and the nutrients in the seed running out before the root system can compensate. Some people have had more success when grafting it onto jackfruit (Artocarpus heterophyllus) or chempejack (Artocarpus integer × heterophyllus) rootstock, but those grafts often don’t take. Has anyone discovered any ways to more reliably keep the seedlings alive?
Thanks for the tips. Seed germination is not an issue, just die-off, mainly from root-rot it appears. Mostly clay soil around here, so drainage is never perfect once the trees are in the ground, though of course I amend the soil with organic material as much as I can. I heard from someone else that ash and lime (CaO) can reduce the incidence of whatever fungal rot damages the roots, so for anyone reading who also has this issue, let’s all try that. Couldn’t hurt.