Hi All,

My meyer lemon is starting to get some yellow spots on the leaves and I'm wondering what could be behind it.




Can anyone help and tell me what's going wrong? It also has a few spots on other parts of the tree where the leaves look like they're being eaten by caterpillars or something similar ... round clean cut sections taken out of the leaves.[/img]

I would say the yellow leaf marks result from using a nitrogen fertilizer high in urea. If the leaf cuts are a pattern with perfect clean circular cuts , then it is probably leaf cutter bees. - Millet (500-)

Thanks Millet.

I'm using the miracle gro "Water Soluble Azalea, Camellia, Rhododendron Plant Food"

http://www.scotts.com/smg/catalog/productTemplate.jsp?proId=prod70346&itemId=cat70044

So is the fix to this problem just to get a more appropriate fertilizer?

I can't tell from the picture what the percentage of Urea is in your fertilizer. Look at the package to determine how much Urea your fertilizer contains contains. The best form of nitrogen for Citrus is Nitrate (N03) - (Millet 500-)

Here's the specs:

Total Nitrogen (N) 30%
3.0% ammoniacal nitrogen
27.0% urea nitrogen
Available Phosphate (P2O5) 10%
Available Potash (K2O) 10%
Boron (B) 0.02%
Copper (Cu) (Soluble) 0.07%
Iron (Fe) 0.325%
0.325% chelated iron
Manganese (Mn) 0.05%
0.05% chelated manganese
Molybdenum (Mo) 0.0005%
Zinc (Zn) (Soluble) 0.07%
Nitrogen from ammonium phosphate and urea; phosphate from ammonium and potassium phosphates; potash from potassium phosphate and muriate of potash; boron from boric acid, chelated copper from copper EDTA; chelated iron from iron EDTA; chelated manganese from manganese EDTA, molybdenum from sodium molybdate; chelated zinc from zinc EDTA.
Potential acidity equivalent to 1200 lbs calcium carbonate per ton.
Chlorine (Cl) Max 7.0%

This is too high in ureea , I belive is for acid lover plants only , and maybe only from time to time for citrus trees

Scotts also have the Universol Green 23-6-10

this is the data I have









GUARANTEED ANALYSIS

23% TOTAL NITROGEN (N)
11,9% Nitrate nitrogen
11,1% Ammonical nitrogen
6% PHOSPHORUS PENTOXIDE (P2O5)
Soluble in neutral ammonium citrate and in
water, 6% water-soluble
10% POTASSIUM OXIDE (K2O)
10% Water-soluble
2,7% Magnesium oxide (MgO)
9% Sulphur trioxide (SO3)
0,01% Boron (B)
0,01% Copper (Cu) chelated by EDTA
0,06% Iron (Fe) chelated by EDTA
0,04% Manganese (Mn) chelated by EDTA
0,001% Molybdenum (Mo)
0,01% Zinc (Zn) chelated by EDTA

Dave, your fertilizer's percentage is quite high in urea. Also chlorine is 7 percent of the formula. Urea is OK to use on citrus if the manufacture insures to use only a highly purified form of urea that is certain to be free of biuret. Citrus is more sensitive than most crops to biuret, an impurity present in urea fertilizer created by excessive heating of chemical reactants during urea manufacture. Toxicity can result from both soil or foliar spray applications of urea with an elevated biuret concentration. The leaf symptoms of biuret toxicity appear as an irregular, butter yellow chlorosis that starts at the leaf tip. Young leaves are more vulnerable than old one, and the affected leaves never re-green. - Millet (500-)

Thanks for sorting this out guys. Is there anything to do about it other than switching to a different fertilizer?

Try to fine a high nitrogen fertilizer using Ammonium Nitrate (NO3-) as the nitrogen source. I use 25-5-15 w/TM which is 100 percent NO3. - Millet (500-)

How does this one look? It looks like the nitrogen is only 40% ammonium. I didn't see anything closer to what you describe searching google.

http://powersearch.amleo.com/help-desk/items/j/j25515/J25515%20Label.pdf


Jack's Pro Water Soluble Fertilizer 25-5-15 High Performance 25lb Bag

Guaranteed analysis: total nitrogen, 25 percent, phosphate 5%, and potash 15%; nitrogen contents are 10.75% ammonialcal, 14.25% nitrate
Minor minerals are as follows: Magnesium 0.1000%, Sulfur 0.1300%, Boron 0.0250%, Copper 0.0125%, Iron 0.1250%, Manganese 0.0630%, Molybdenum 0.0125%, Zinc 0.0630%

Nevermind. I searched some of the other fertilizer threads and it sounds like that one is good to go. I'm going to order a bag. 25lbs ought to last me a lifetime.

In my estimation Jack's 25-5-15 is the absolutely best citrus fertilizer for containerized citrus. I normally purchase it in 50-lb. lots (2 X 25-lb. bags) at a time. Jack's 25-5-15 has the perfect 5-1-3 ratio. (Millet 499-) -- *Down another 100 days!!

Well Millet what about us , those who don't live in US , so there are other options , so except Jack's , what other product can be used ?

danero, actually any high nitrogen, low phosphorous, non biuret fertilizer, with good levels of potassium should do OK. - Millet (499-)