this particular carica seedling grew normally until it was around 5” tall, and then it started to languish. i assumed it wasn’t getting enough water, and i tried to remedy this, kinda. honestly it wasn’t a very big priority.
two days ago i learned the real reason that the seedling had been struggling…
those nodules are filled with the tiny worms of root knot nematodes (rkn). it might not be a coincidence that the pot originally had a gummy worm tree (cecropia) in it from costa rica.
back in 2022, when i visited costa rica for the 1st time, i collected small samples of epiphytic mosses from various trees. i thoroughly dried the moss before bringing it home and putting it in pots in zip lock bags. needless to say i was bit surprised when a couple cecropias popped up in the moss and grew crazy fast. sadly the one i kept didn’t survive its 1st winter outside here in sylmar (san fernando valley / los angeles). but i left the pot alone because it had other plants happily growing in it… a nephrolepis fern and pepperomia also from costa rica, as well as a canna.
a couple days ago i decided that i needed the 7 gallon pot for higher priority plants, which is when i discovered rkn on the roots of the carica seedling.
whenever you bring a plant into your garden, unless its in a sterile flask/jar/bag, then its guaranteed you're also bringing in other organisms. for example, one tablespoon of garden soil can have around 100,000 different species of microorganisms. hitchhiking organisms, as a whole, are going to do more good than harm. they will add to your garden’s biodiversity, which will make it more resilient. the less biodiverse your garden is, the greater the potential damage by pests and pathogens, which is the fatal flaw of monocultures. the lesson of the potato famine has not been adequately learned.
ficus carica cultivars aren't equally susceptible to rkn, and the same is even more true of carica hybrids. in order to illustrate this i put the rkn carica seedling back into the same 7 gallon pot, with the same medium, and surrounded it with 4 of my carica hybrids…
i tried to strategically arrange the carica’s roots to facilitate rkn exposure to my hybrids. then i added the rest of the soil…
left: ficus ulmifolia x carica, a couple small ficus racemosa x carica, and a guava
top: ficus opposita x carica (oppcar), a rooted cutting from my first to fruit
right: ficus fraseri x carica, and ficus ulmifolia
bottom: ficus racemosa x carica
center: ficus carica with rkn
there was just enough left over soil for a 3 gallon pot…
left: ficus oppcar, a rooted cutting from my first to fruit
right: ficus carica
bottom: ficus palmata hybrid
i wanted to give this particular oppcar the chance to redeem itself, since i recently learned that its susceptible to black fig fly. but for all i know it also inherited susceptibility to rkn from its carica father. the proof is in the pudding.
yesterday i started two more rkn experiments using a couple of infested ficus caricas. around a year ago i received two boxes filled mainly with cuttings of numerous different varieties of carica freely given to me by a generous older collector in the san diego area. also included in one of the boxes were a couple of bare root caricas, which had numerous nodules of rkn on their roots. i guessed that perhaps the collector’s eyesight was quite poor. in any case, i decided to use the rkn caricas to test ficus cocculifolia’s resistance to rkn. i chose this ficus species because its graft compatible with carica. i put a small rooted cutting of cocculifolia and the larger rkn carica into a 5 gallon pot. the carica barely grew, unlike the cocculifolia. here’s a pic i took yesterday…
i unpotted the cocculifolia and carica. here’s a side by side pic of their roots…
the cocculifolia roots had no noticeable nodules. so this ficus has set the standard in terms of rkn resistance and carica graft compatibility.
i split the rkn soil from the 5 gallon pot that the 2 ficus had been in between a 7 gallon pot and a 5 gallon pot and mixed it with some really nice medium. in the center of the 7 gallon pot i put the larger rkn carica and surrounded it with seedlings…
left: ficus palmata hybrid
top: ficus oppcar
right: ficus ulmifolia x carica, jaboticaba, acacia pendula
bottom: ficus racemosa x carica (x2)
in the center of the 5 gallon pot i put the smaller rkn carica and a couple seedlings…
left: ficus oppcar
right: ficus ulmifolia x carica, jaboticaba
in theory, rkn should have no problem colonizing the 4 experimental pots. the medium i used is very chunky and airy so it should suit the rkn’s need for elbow room.
one tragic problem with this experiment is the use of unique seedlings. if a seedling gets killed by rkn then it will never realize its potential. for all we know it might have produced the best tasting fig that’s resistant to the black fig fly. so its always preferable to experiment with rooted cuttings. i was regrettably impatient.
several of the seedlings were basically bonsais though. i want to pot them all up to see which ones grow and fruit fastest in my conditions. unfortunately the logistics are quite challenging. moving plants from here in sylmar california to my 10 acre experimental grove in sebring florida is one thing, but having the time to plant them all is another thing entirely. i have one worker in florida but his hands are nearly full dealing with just the weedy vines.
therefore, i need to sell seedlings. i asked fighunter downhunter if it was ok to use this forum to do so and he gave me permission.
the first thing i’m planning to auction here are my ficus palmata hybrid seedlings. ficus ‘iraqi’, which is a natural cross between palmata and carica, is the global standard in terms of rkn tolerance. tolerance or resistance? a tolerant plant will develop root nodules but is vigorous enough to outgrow them. a resistant plant won’t develop nodules. i don’t get the impression that pure palmata is resistant to rkn, so i’m not sure why any of its hybrids with carica would be.
ideally someone would stick a rooted ficus iraqi cutting in the same pot as a carica with rkn. personally i don’t have iraqi. coincidentally, yesterday “grow in the flo” in florida (orlando) posted a youtube video of his iraqi growing in the ground. seems like its growing quite well, same with his other palmata hybrid in the ground, alma.
“grow in the flo” regularly posts in this private florida fig group on fb started by roy boone. joining his group is a really good idea if you’re in florida and interested in figs. he recently shared in his group a video of his iraqi, cherry cordial and yellow long neck in the ground. cherry cordial is in theory a palmata hybrid as well, and he was happy enough with its performance to plant a second one.
what blows my mind is the production of iraqi in thailand. check out this public fb group for fig growers in thailand. here are the search results for iraqi. most of the posts are from the same vendors but still, lookit this post. that’s a huge amount of air-layers!
the global demand for a better rootstock for carica in the subtropics and tropics is hard to comprehend. who is going to meet this supply? currently a vanishingly small percentage of fig producers in thailand know that its possible and desirable to cross ficus carica with other species. but once they all finally get the memo, then i’m confident they are going to do some great things with figs.
recruiting talent to the cause of fig breeding is our most important mission. right? the more talent we throw at rkn the sooner we'll defeat it.
