Color variance in palm leaves - explanation

[byuind]

Looking at a couple of my P Elegans, I noticed that the newer leaves have started to come out a lighter green. My first thought was “hey, maybe needs more iron?” 
 

but I pumped the brakes on that because I wanted to make sure that I fully understand the variance in color. I’ve noticed lighter leaves on several of my trees the last month or so (newly emerged). Do you see variance based on time of year? Or is it always a chemical imbalance?

 

sorry if the pictures aren’t totally clear- there is a significant color difference between the newer leaves and some of the older ones 

 

[SeanK]

Good Question.

Certainly, leaves that develop under low light are a darker green. Perhaps, the excess of chlorophyll leads to sun sensitivity. Not all chlorophyll is created equal. It show up in a variety of colors, as witnessed on sugar maples in autumn.

We need an expert explanation.

[sonoranfans]

15 hours ago, SeanK said:

Good Question.

Certainly, leaves that develop under low light are a darker green. Perhaps, the excess of chlorophyll leads to sun sensitivity. Not all chlorophyll is created equal. It show up in a variety of colors, as witnessed on sugar maples in autumn.

We need an expert explanation.

sugar maples are not red or orange or yellow due to chlorophyll but rather the lack of chlorophyll coupled with remaining carotenes, xanthins and anthocyanins which remain in the leaf after the tree produces the colorless breakdown products of chlorophyll.  Chlorophylls have two main types, chlorophyll A and chlorophyll B which are slightly different greens with differing blue content(shift).  Generally when leaves yellow its because the chlorophyll is either not in the leaf or doesnt have Mg to give the chlorophyll molecule its green color.  Yellows are carotenes and reds are anthycyanins.  Xanthins can be orange or yellow.  Palms do not enter senesence annually, they just remove the chlorophyll from leaves, and some break down to colorless, leaving behind the colorful, fixed xanthins, anthocyanins and carotenes.  Since Fe(Iron) is key in the synthesis of chlorophyll a deficiency negatively impacts synthesis in (the newest leaves) and causes general yellowing.  Complexing of magnesium with chlorophyll produces the green color so if Mg is unavailable you wont get a green pigment.  SO to be simple, Mg unavailable, no green Mg complex, If Fe is unavailable no chlorophyll is produced.  

[SeanK]

4 hours ago, sonoranfans said:

sugar maples are not red or orange or yellow due to chlorophyll but rather the lack of chlorophyll coupled with remaining carotenes, xanthins and anthocyanins which remain in the leaf after the tree produces the colorless breakdown products of chlorophyll.  Chlorophylls have two main types, chlorophyll A and chlorophyll B which are slightly different greens with differing blue content(shift).  Generally when leaves yellow its because the chlorophyll is either not in the leaf or doesnt have Mg to give the chlorophyll molecule its green color.  Yellows are carotenes and reds are anthycyanins.  Xanthins can be orange or yellow.  Palms do not enter senesence annually, they just remove the chlorophyll from leaves, and some break down to colorless, leaving behind the colorful, fixed xanthins, anthocyanins and carotenes.  Since Fe(Iron) is key in the synthesis of chlorophyll a deficiency negatively impacts synthesis in (the newest leaves) and causes general yellowing.  Complexing of magnesium with chlorophyll produces the green color so if Mg is unavailable you wont get a green pigment.  SO to be simple, Mg unavailable, no green Mg complex, If Fe is unavailable no chlorophyll is produced.  

Thanks. Good explanation.

[byuind]

So basically supply more Fe and Mg is what I’m taking from this…

 

on it

[flplantguy]

Plants will use more minerals during hotter weather also so this appears more now when whatever early summer fertilizer has started to wear off.  We used to sell a minor element package for this that southern ag made.  They may still have it.

[sonoranfans]

14 hours ago, byuind said:

So basically supply more Fe and Mg is what I’m taking from this…

 

on it

if the pH is alkaline, iron will have limited bioavailability you may get better results if the iron is chelated in alkaline soils.  If you use a good palm fertilizer the proper ratios of these elements will be presented when you spread the fertilizer.  Dont make it more complicated than it has to be, as adding individual nutrients can lead to ratios that can cause them to compete and that could cause a deficiency in one of them.  No need to reinvent the wheel.  Florikan and palm gain are two good ones.  Florida has high phos(P) soils so the P number in NPK is going to ideally be 1/4 of the N number and 1/6th of the K number.  So 8-2-12 are the NPK ratios.  If your soil P levels are too high it can inhibit uptake of N, Zn Fe and Co.  Ag schools have identified the best ratios for different states.  Florida needs a lower P and a higher K than some other states like CA TX.  CA/Mg ratios are important as if one is too high it can limit uptake of the other.  Fe is also ratioed for best results.  Adding a little extra Fe does not lead to uptake issues of other nutrients.