Pritchardia seedling yellowing

[John in Andalucia]

This is my treasured P. martii that I grew from seed, sent to me by Wai`anae Steve last Christmas, and on the right is how it looks today.

I had a thought in the back of my mind when I noticed the tip of the oldest leaf, because the yellow colour looked quite intense. But I just thought it was dying back. Now several weeks later and it has spread, even to the tip of the emerging leaf. The yellowing is punctuated by translucent spots. Can anyone help on this? Should I isolate it from my other greenhouse palms? Will it die if left unattended? Thanks, everyone.

[paulgila]

have you checked it for mites?

[MattyB]

I was thinking the same thing. Maybe mites. Pritchardia are especially suseptible to mites in the greenhouse. Yours looks like it could use some fertilizer too. Overall, that plant looks like it's doing fine. Keep it watered and fertilized and it should continue to grow well. Pritchardia do the yellow splotches sometimes for various reasons.

[BS Man about Palms]

Make it a 3 vote for mites...

[mike in kurtistown]

Also, at a young seedling stage, Pritchardias can show some leaf yellowing from too much full-sun exposure. They survive it, but look better under light shadecloth.

[John in Andalucia]

Thanks for the "A-Team" response. Incidentally, I have a lot of Veitchia arecina coming up, and the problem I have there is 'white spider mites'. Is it the same culprit? I'm using an insecticide for citrus trees on them. Will it do the job for both? Light spray or a good drench? I'm new to infestations. Mike, the bench down one side of my greenhouse is under heavy shade cloth, and that's where I keep it.

[paulgila]

i have never noticed mite spray for specific trees so one would think it would work. make sure & spray both sides of the leaves,a good drench shouldn't hurt the plant.

[DoomsDave]

It looks okay to me.

One problem pritchies face is lethal yellowing, though I rather doubt you have it in Spain.

Hmm. Any more of them? I hope Steve sent you more than just one seed!

That is a great species, if my memory serves, dwarf habit. Also, I'd put it outside as soon as you can. Hawaiian Pritchies take Mediterranean conditions very well, unless you're prone to frosts, in which case I'd wait till spring.

[John in Andalucia]

Thank you amigos. I had two seeds from Steve, the other one I germinated, but it went bad. That's a pretty rare palm over here, you know.

I will follow your advice, Dave. Growing so many tropical species under cover, I tend to consider many of them the same. The palms I keep outdoors are the Phoenix, Livistona, Syagrus, Parajubea, etc. My most exotic outdoor palms to date are Bismarckia and Chambeyronia, but yes, the Loulou's will follow!

[Rusty on Pine Is.]

Thanks for the "A-Team" response. Incidentally, I have a lot of Veitchia arecina coming up, and the problem I have there is 'white spider mites'. Is it the same culprit? I'm using an insecticide for citrus trees on them. Will it do the job for both? Light spray or a good drench? I'm new to infestations. Mike, the bench down one side of my greenhouse is under heavy shade cloth, and that's where I keep it.

John, if the pesticide you are using has mites on the label, you should be good to go.......although you should be alternating sprays with another miticide from a different chemical class to avoid resistance....one application seldom if ever works.....and a good ovicide will really help.

Rusty

[Kostas]

Buy a good biocontrol insect and you should be good for all the rest of the year and maybe for the years to come too and without being exposed to chemical and harmfull pesticids

Till then,you could wash them from the mites and increase aeration along with humidity.This should keep them laying low or even vanish with regural washes

Btw,regardless of the mites,your Pritchardia is very beautyfull!!! I love the long drooping leafs!

[BS Man about Palms]

Also, if you don't have a fan in your greenhouse you should put one in. Mites don't like the air movement. "Still" greenhouses can get hit bad....

[John in Andalucia]

That's some good advice, peeps. I have a fan set up, though I admit, the air circulation below bench height is not the best. I'll get onto it today and let some more air in to the greenhouse, and get zapping. Maybe a second mite spray as Rusty suggests. Thanks Kostas, for your advice. Biocontrol is something that would suit my environment, most definitely.

[Morabeza]

So very many pesticides are erroneously marketed/labelled as miticides. This can be very frustrating when they prove inffective, possibly phytoxic and also prolonging a mite infestation. Varying species of mites are a problem in Hawai'i depending on humidity level, elevation, rainfall and temperatures. With PLENTY of natural air movement I have still had to battle mites, esp. on Pritchardia spp., including P. martii that I germinated myself. Once they are in check they are less troublesome

For control of mites wettable sulphur does a good job as long as it has direct contact with the insects. Re-application of wettable sulphur must be repeated at least every 5-7 days for about 3 weeks to rid infested plants of the mites. The advantage of wettable sulphur is that is is one of the more 'organic' choices, the downside is that every abaxial leaf surface needs to be sprayed in order for effective mite control. Depending on the brand and make-up of wettable sulfur a white or grey residue will stay on the treated leaves for a while. Also, sulphur is quite smelly!

If you have lots of money to spend and aren't married to a 100% organic approach there are some very effective 'new generation' miticides that work in a translaminar fashion and stay in the plant's vascular system for months (can be called 'systemic' miticides). I have used Pylon® and Avid® (names sold under in the US) quite effectively and painlessly (except for the pain of having to pay quite a lot for the products). While they don't leave a residue nor do they smell as foul as sulphur, there are other cautions to consider as there are with all agro-chemicals.

Best wishes!

[MattyB]

I'm experimenting with using Diatomaceous Earth right now. Add it to water in a spray bottle and spray everything. Sure, your plants all look like they've been flocked for Christmas but it seems to keep the mites off everything. I'm in the preliminary stages right now but so far it's working better than any insecticide I've used so far. Also, using the food grade stuff, it's completely harmless to us.

[paulgila]

i am using the "toxic" DE.

hack,hack.

[MattyB]

My Dad and I split a 10 pound bag. He's eating his. Seriously, 1 tablespoon a day in his coffee. It's supposed to be a good dietary suppliment. This is the food grade stuff people, don't be eating pool filter DE and say I told you to do it. And when I say people I mean PAUL!!!!!

[paulgila]

huh? were you talking to me?

[John in Andalucia]

I've found Diatomaceous Earth for sale on eBay, and it looks like it might be the way to go. I can't see it for sale in Spain, though. It would be better than using chemicals and probably cheaper. How is your Dad, Matty - are you being serious?

[John in Andalucia]

For anyone interested, I've found both a supplier and manufactuer in Spain for "tierra de diatomeas". Here's a link: http://www.tierradediatomeas.com/

I'm trying to read the page about how they mine it. Well done, Matt for bringing this up.

[peachy]

Pritchardias usually do well for me here, surviving even a black frost with only a tiny bit of cosmetic damage. P. hillebrandii sp blue dwarf grows like a weed, and the other species I have grow strongly too. However, earlier this year I bought a P. hillebrandii (full size species) and for a while he was great then he started going yellow and the leaves (fat straps) drooped badly. I really thought it was history but there is a new spear coming up so maybe (just maybe) it will pull through after all. Not sure if I have P.martii or not. I do if it is called P. gaudi chaudii here and though not madly fast growing, it is one tough little palm, unless the bloody grasshoppers get to it. Good luck with your baby

Peacy

[John in Andalucia]

Thanks Peachy. There appear to be a whole host of plants with the species name gaudichaudii, but I haven't a clue about the origins, or whether it has ever been used in conjunction with palm names, but P. gaudichaudii is a South American hermit crab - Propagurus gaudichaudii.

[peachy]

Well it certainly makes me very CRABBY when those rotten grasshoppers eat it.

Peachy

[John in Andalucia]

Well actually, you are right Peachy! Pritchardia gaudichaudii is a synonym of Pritchardia martii. I should have checked the World Checklist before doing a Google search. I wonder were the name comes from?