Diseased Rhapis?

[bdaalex]

I’ve had this potted Rhapis for a few years and it’s been doing well. It sits 10’ from another Rhapis that is still healthy and dark green. Both are in a north facing covered porch and get the same water. 
 

this one is yellowing, to a mottled or in some areas, variegated effect. Also, a small new shoots has leaves that are almost white.  It had spider mites a year ago but I cleaned it and trimmed off the worst leaves. The changes have been since then and I see no sign of pests. 
 

It has granule fertilizer on top of the soil, but I have not used water soluable or amended the soil. 
 

help?

 

 

[Merlyn]

White new shoots is a classic sign of iron deficiency.  It's usually caused by soil that stays too wet and mucky.  The spottiness/variegation look could be a combination of nitrogen and/or potassium deficiency, it's hard to say.  But I think the major issue is probably wet soil causing root rot and/or iron uptake problems.  Here's my notes on nutrient deficiencies:

• Nitrogen - Older fronds turn light green uniformly, new fronds remain dark green until deficiency is really severe
• Potassium - Older fronds get translucent yellow/orange or dead spots on leaves, especially at the tips. Caryota and Arenga get random splotched dead spots in leaves. Sometimes tips are curled or frizzled. Always starts at tips of oldest leaves, moving inwards
• Magnesium -Yellow linear bands on oldest leaves first, transitions to solid green at the base of each leaf. Never causes leaf tip necrosis
• Iron - Many times caused by overly mucky soil and root rot. Starts with new spear leaves with yellow-green or even white, possibly with spots of green.
• Manganese - Lengthwise necrotic streaks in leaves with dead and curled leaf tips. Similar to bands showing Magnesium deficiency
• Boron - Bent or necrotic or distorted leaf tips, distorted or bent spear, bands of dead spots on new fans, spears that won't fully open
• Water - Underwatering brown at the edges first, later followed by yellowing of the whole leaf. Overwatering can be drooping fronds turning yellowish and losing color
• Dolomitic Lime or Azomite - Magnesium Carbonate – reduces acidity/raises pH – slower release and adds Magnesium, helps avoid Potassium deficiencies in Cuban Copernicias. 5Lb per palm on full-size Copernicias and a bit less on Kentiopsis Oliviformis
• Garden Lime - Calcium Carbonate – fast release but works well. 5Lb per palm on full-size Copernicias and a bit less on Kentiopsis Oliviformis

I don't do any indoor palms, so I can't recommend a specific watering regimen.  In the "Palms in Pots" section of the forum there are a lot of threads on people's preferred soil mixes.  Generally you want something that drains quickly and is around 50-75% inorganic.  That might sound weird, but you are better off watering more frequently and having the soil drain and dry out quicker.  Soil that stays wet all the time can quickly rot roots.  As an example, my outdoor palms in pots are in a soil mix that's equal parts generic topsoil, perlite, Turface MVP and Sakrete Paver Base (crushed limestone gravel).  That makes it about 25% organics.  If the plant is a water-lover then I mix it with a bit more organics, and for things like agaves and aloes I use very little organics.  The perlite and Turface holds a reasonable amount of water, but gives it good aeration to avoid root rot.