Ravenea g. Andringitra problems ?

[Darold Petty]

  I was fortunate to obtain 3 seedlings from 50 seeds, but am having difficulty with the plants.  Please refer to LJG's excellent thread for background about this palm.

One of my three seedlings died almost immediately after potting up.  The two survivors grow at an acceptable rate, but the older foliage suffers the damage shown, and the small plants are not really increasing the surface area available for photosynthesis.  I am careful not to overwater these palms, and have used chlorothalonil with every irrigation.

  What is the cause of this damage, and how can I prevent this damage ?

Thanks for your observations and advice !

[joe_OC]

Have you checked on the underside of frond?  The concentrated dark sports remind me of insect damage like mealybugs?

[Darold Petty]

I can't detect any bugs.  I'm thinking this problem is a bacterium or fungus.

[Tomas]

Do you use the chlorothalonil for watering? It is a non systemic fungicide for leaf coverage, so it wouldn't be of much use. It has also a good persistence, so no need to use it so often. In the italian label fo chlorothalonil I can read "not more than two, three applications", could yours be the damage from too frequent application?

Tomas

[Tomas]

BTW, I acquired ten seeds and they started to rot immediately after sowing

 

[Darold Petty]

Thank you, Tomas.  That is a very good observation.  I was not aware of these facts, and  I had started to use chlorothalonil based just on the recommendation of a friend.

  A quick search for 'systemic fungicide' yielded propiconazole as the most common product.  Has anyone used this chemical on seedling palms? Thanks !

  Has anyone used a chemical called 'Physan20' ?

[LJG]

Darold, I got your PM, but sorry I am not sure I can add much to this. I too have had tough luck with these too I lost most mine to collar rot. I have one plant left that I saved from the rot. I don't get the browning leaves like you do, however. Do you have peat in your mixes? I try to limit it.

One thing you might want to try is potting them into those larger, deep cactus pots early. Mine grew quickly when potted up. Once you take them out of the pot yours are in, you will see why. These form fat, deep roots. Once they start to grow and fatten up, watch for collar rot. Im not sure why, but as the old leaf bases split off as the base expands, fungus loves to hit that spot. It's very frustrating. 

Nice work on your germination rates. I think I recall Jeff saying that out of like 2000 seed, he only got a few handful of plants. The seed was either really old, or picked green, I can't remember which. 

-------------

Chlorothalonil is the active ingredient in Daconil and can be found at Home Depot. I use that all the time for leaf spot fungus. Works great. I don't think I have ever used propiconazole. From experience I have found the two best systemics to be Cleary 3336F (Thiophanate-methyl) and Subdue. They each treat totally different fungus. 

[Phoenikakias]

3 hours ago, LJG said:

Darold, I got your PM, but sorry I am not sure I can add much to this. I too have had tough luck with these too I lost most mine to collar rot. I have one plant left that I saved from the rot. I don't get the browning leaves like you do, however. Do you have peat in your mixes? I try to limit it.

One thing you might want to try is potting them into those larger, deep cactus pots early. Mine grew quickly when potted up. Once you take them out of the pot yours are in, you will see why. These form fat, deep roots. Once they start to grow and fatten up, watch for collar rot. Im not sure why, but as the old leaf bases split off as the base expands, fungus loves to hit that spot. It's very frustrating. 

Nice work on your germination rates. I think I recall Jeff saying that out of like 2000 seed, he only got a few handful of plants. The seed was either really old, or picked green, I can't remember which. 

-------------

Chlorothalonil is the active ingredient in Daconil and can be found at Home Depot. I use that all the time for leaf spot fungus. Works great. I don't think I have ever used propiconazole. From experience I have found the two best systemics to be Cleary 3336F (Thiophanate-methyl) and Subdue. They each treat totally different fungus. 

Do you apply both combined or at different times?

[Tyrone]

Sorry to see that Darold. I have no idea what's going on with them. They're not happy. Mine have been an absolutely easy grow. I've got 4 doing fine with no rot. I water mine about once a week with seaweed and fish and they seem to love it.

[Darold Petty]

Thanks to Len and the others.  I have learned about the fungicides and their different properties. I did not know that the application method is important. I will be more careful about the foliar versus root drench issue.

  Tyrone, my friend 'Tassie Troy' in Hobart is a big proponent of seaweed.  His garden is perfect, and is truly remarkable for his latitude.  I have now started to use liquid kelp extract with the seedling irrigation.

 Lastly, I believe that the cause of this poor germination and rotting is the result of the seeds being harvested too immature.  This is especially tempting when the seed location is difficult and costly to access. (We are here, it is now or never!)

  I have direct experience with this as well.  When I went to the Ecuador location of the red G. undata I collected about 50 seeds of a small, interesting Prestoea.  The seeds were full sized, but the epicarp had not yet changed from green to the mature color.  Only 1 of these seeds germinated.

[BS Man about Palms]

9 hours ago, LJG said:

Darold, I got your PM, but sorry I am not sure I can add much to this. I too have had tough luck with these too I lost most mine to collar rot. I have one plant left that I saved from the rot. I don't get the browning leaves like you do, however. Do you have peat in your mixes? I try to limit it.

One thing you might want to try is potting them into those larger, deep cactus pots early. Mine grew quickly when potted up. Once you take them out of the pot yours are in, you will see why. These form fat, deep roots. Once they start to grow and fatten up, watch for collar rot. Im not sure why, but as the old leaf bases split off as the base expands, fungus loves to hit that spot. It's very frustrating. 

Nice work on your germination rates. I think I recall Jeff saying that out of like 2000 seed, he only got a few handful of plants. The seed was either really old, or picked green, I can't remember which. 

-------------

Chlorothalonil is the active ingredient in Daconil and can be found at Home Depot. I use that all the time for leaf spot fungus. Works great. I don't think I have ever used propiconazole. From experience I have found the two best systemics to be Cleary 3336F (Thiophanate-methyl) and Subdue. They each treat totally different fungus. 

Len, have you tried that Chlorothalonil on that Gomez-ponapae for the spots? I would like to try something.

[Josue Diaz]

I hope you find a solution to your problem Darold. It would be such a loss of either of those died. 

I'm looking forward to seeing yours and others of this species mature and set seed in California. I'll be the first on the lists for seed when they do. 

[LJG]

2 minutes ago, BS Man about Palms said:

Len, have you tried that Chlorothalonil on that Gomez-ponapae for the spots? I would like to try something.

I did years ago on the Princeps actually. I also did on my Kentiopsis oliviformis. Didn’t see much help. Later I read in some article (maybe written by Hodel?) that in a study they found lack of Iron and other nutrient intake in winter leads to the fungus leaf spotting. I used SulPoMag and chelated iron in fall now and it helped with the KO. Same with my Foxtails. Well, either that or maturity of palm did it  The iron and SulPoMag trick never worked on the Princeps. So I got rid of it. 

[LJG]

6 hours ago, Phoenikakias said:

Do you apply both combined or at different times?

Depends. If it is in the greenhouse, I’ll sometimes  use both as cocktail. Outside I just use Clearys. I know that mixing different fungicides or pesticides can cause a reaction to make them inert, but I didn’t read any warning on these two and I haven’t noticed any issues with mixing. 

[Phoenikakias]

14 hours ago, LJG said:

I did years ago on the Princeps actually. I also did on my Kentiopsis oliviformis. Didn’t see much help. Later I read in some article (maybe written by Hodel?) that in a study they found lack of Iron and other nutrient intake in winter leads to the fungus leaf spotting. I used SulPoMag and chelated iron in fall now and it helped with the KO. Same with my Foxtails. Well, either that or maturity of palm did it  The iron and SulPoMag trick never worked on the Princeps. So I got rid of it. 

I have heard something similar with the lack of ... zinc!

[Phoenikakias]

On 12/3/2018, 9:55:52, LJG said:

Darold, I got your PM, but sorry I am not sure I can add much to this. I too have had tough luck with these too I lost most mine to collar rot. I have one plant left that I saved from the rot. I don't get the browning leaves like you do, however. Do you have peat in your mixes? I try to limit it.

One thing you might want to try is potting them into those larger, deep cactus pots early. Mine grew quickly when potted up. Once you take them out of the pot yours are in, you will see why. These form fat, deep roots. Once they start to grow and fatten up, watch for collar rot. Im not sure why, but as the old leaf bases split off as the base expands, fungus loves to hit that spot. It's very frustrating. 

Nice work on your germination rates. I think I recall Jeff saying that out of like 2000 seed, he only got a few handful of plants. The seed was either really old, or picked green, I can't remember which. 

-------------

Chlorothalonil is the active ingredient in Daconil and can be found at Home Depot. I use that all the time for leaf spot fungus. Works great. I don't think I have ever used propiconazole. From experience I have found the two best systemics to be Cleary 3336F (Thiophanate-methyl) and Subdue. They each treat totally different fungus. 

What is the active ingredient in Subdue? I have googled it up, but it looks like that under this market insecticides are being sold worldwide with various active ingredients. Anyway I have applied, based on present information, a cocktail of thiophanate methyl and metalaxyl on a seriously ill palm seedling with encouraging results, as it has pushed some fresh green after the dead part of the central leaf.