Hi John,
You should try next time to get deep black nursery pots, atleast 30cm deep. Avocados tap root grows very fast and if your location is prone to strong winds. will help the trees to establish much faster and be less prone to uprooting in high winds.
I have looked for deep platic bags, or 'sleeves', to plant avocado and mango, but they are not available in Fiji. In fact, I could not even find inexpensive plastic sleeves of this size on the internet. If anyone knows a source of plastic sleeves that are 12-16 inches deep (300-400 mm) but only 5 or 6 inches wide (15-150 mm), please let me know.
John so far as guatemalans go the ones that would go ok in your climate are the same types I grow.In order of success in a warm climate are shepard,reed,hazzard and wurtz with even sharwill struggling.Seedlings of reed seem to have good fruit on some of the progeny and keep their spherical shape.Hass cannot be grown on the coast here but on the adjacent tablelands where there is frost tonight hass is the second most popular commercial variety.Grafted trees would be so much better but getting them from overseas would not be easy.
Australia has the Sheppard and Reed varieties you suggest, so I may be able to get seeds from there next season. Getting a seedling plant into Fiji legally would be nearly impossible with our biosecurity department. The Fiji Department of Agriculture does nothing with avocado so I'll be looking for an overseas source. Thanks for the insight.
John, check out the drawing on this page: http://jhered.oxfordjournals.org/content/35/7/209.extract Seems like your seed looks more like drawing A than drawing B due to the multiple tap roots.
My seedling does look more like 'A', the poly drawing, but as Tim pointed out, there is no apparent splitting of the seed into sections like we see in mango.
My intention is to graft Hass (which I have now) and next year hopefully some more appropriate varieties from Australia, onto the local avocado rootstock (large green type) that is well-suited to my soil and climate.
John