Mango Pests, Diseases, and Nutritional Problems

[onur]

HiThe tips of the branches of my mango tree (pina colada) are getting dark and the panicles are drying. What does it stem from?Thanks

Looks like Powdery Mildew (PM), definitely some sort of mold or fungus. Not sure how susceptible PC is to PM, some varieties fight it off and hold onto their flowers/fruit better than others. It can lay waste to an entire tree's flowers/tiny fruit, but it seems like most the time some amount of fruit hangs on. You can spray sulfur/potassium carbonate as a preventative/treatment or try trimming it out. I've been trimming this year, it's definitely working in controlling spread, but it's time consuming (I'll probably spray next season).

I had sprayed neem oil already. I will spray sulfur after a week. Probably, pollinators will keep away for a while... Thank you.

[JakeFruit]

HiThe tips of the branches of my mango tree (pina colada) are getting dark and the panicles are drying. What does it stem from?Thanks

Looks like Powdery Mildew (PM), definitely some sort of mold or fungus. Not sure how susceptible PC is to PM, some varieties fight it off and hold onto their flowers/fruit better than others. It can lay waste to an entire tree's flowers/tiny fruit, but it seems like most the time some amount of fruit hangs on. You can spray sulfur/potassium carbonate as a preventative/treatment or try trimming it out. I've been trimming this year, it's definitely working in controlling spread, but it's time consuming (I'll probably spray next season).

I had sprayed neem oil already. I will spray sulfur after a week. Probably, pollinators will keep away for a while... Thank you.

If I recall correctly, sulfur is only useful as a preventative; once the PM sets in, you need potassium carbonate or some other chemical to fight the PM. Do some quick research before you use the sulfur, it might not do anything against the PM situation you are facing.

[fliptop]

This is on some Sugarloaf fruitlets. Not all, thank goodness gracious. What is it and should anything be done? Thanks!

[leanne.rodrigues17]

Hi Har,

I’m going a mango plant from seed. Started growing it in July of 2022. This past month, the leaves at the top have started gaining these black spots on the edges and have slowly moved downward.
I thought it was anthracnose so I started spraying it with a copper fungicide weekly….it still seems to be spreading.
What am I doing wrong?? Any idea what this is? I’ve already lost 3 leaves and it feels like I’m about to lose another!!!

[DuaneC59]

4 weeks ago I began applying weekly copper to the new buds on this PPK.  We had several days of temps down to 35 degrees followed by heavy rain. In the last 2 weeks most of the buds that I sprayed have turned brown but the PPK has the leaf changes shown here and the dead flowers.  I thought most of the copper had been washed off by the rain which was heavy for Southern California. I see similar bud damage on most of the trees that I sprayed except  Sein ta Lone and a few others. The copper was pretty dilute - only 3ml of concentrate per quart.  I am in California, Zone 9b/10a.  Any thoughts?

Thanks.

[Guanabanus]

Duane,
Which copper product did you use, and how much does the label say to use per gallon?

[Guanabanus]

Fliptop,
Probably a deficiency of Boron.

[Guanabanus]

Leanne,
Is the potting soil quite black and wet, or actually compost?

[Guanabanus]

tropical tree for me,
Scale insect infestation.  I don't know specific pest identification or product availability in Laos.

Neem oil sprays, with several repetitions about a week apart, in cool evenings or very early mornings.  Follow label instructions of your product.

[fliptop]

Thank you, Har!

[DuaneC59]

Duane,
Which copper product did you use, and how much does the label say to use per gallon?

Thanks Guanabanus,
It was BONIDE brand 0.5 to 2 fl ounces per gallon. My solution was very dilute (~12 ml per gallon). I was applying it weekly to closed buds.

[Guanabanus]

Duane,
Yes, that small amount of Copper Soap should be safe, at it is under the minimum recommended rate.

However, you previously said that amount per quart, rather than per gallon, which would almost be the maximum labelled rate.

[Calusa]

Anyone know why this small mango would have fallen off the tree? Maha in the ground almost 3 years. Last week I saw some watery sap running down the fruit and this morning I found it on the ground. There is only a few small fruits on the tree at this time. Tree too young maybe?

[TheVeggieProfessor]

Hi all. This is on the new growth of my Glenn and Pickering. Any ideas?

[drymifolia]

I just noticed that my greenhouse mango seedling -- which looks otherwise healthy -- has some suspicious looking white splotches on the still-green stem just above ground level. Is this powdery mildew or some kind of pathogen I should be concerned about?

[Guanabanus]

Caloosa, probably
Someone, or the wind, partially twisted off the fruit.  Where the stem was half detached, sap flowed. 
Later, the stem deteriorated and was unable to hold.

[Guanabanus]

Veggie Professor,
Root inefficiency caused by dry, chilled soil, commonly causes episodic nutritional deficiencies of zinc, copper, calcium, sulfur, etc.
The small or misshapened leaves are very susceptible to infections.  I see mostly anthracnose--- grey-black --- and a few mango bacterial black spots--- coal-black.

Use mixed fertilizers with all the micronutrients, and use gypsum, and spray with copper and other micronutrients.  Avoid the 0-0-52 fad.

[Guanabanus]

drymifolia,
Hardening bark.

[MJ88]

I just got this mango tree today. It's an alphonso mango and I'm concerned it was shipped to me already having some fungus or a disease. As you can see in the pictures the main stem has black all over it where it should be green and some of the leaves have brown spots. The reason it looks wet is because I just sprayed it with some fungicide, just a Dr. Earth organic fungicide, nothing to major or toxic, I don't wanna do that until I know I need to. Any advice would be great, I'm new to mangoes. Please let me know if you think it's a fungus, I hope not, I just got it, it shouldn't already have a disease or fungus that would totally suck.

[MJ88]

For some reason this picture didn't post. You can really see the black stuff I'm talking about in this picture. It doesn't look like it should be there. I don't think that's normal. I've seen lots of pictures and videos of mangoes and they usually don't have black stuff growing on the young green trunk/stem.

[fliptop]

I am down to seven fruit on my seedling Coconut Cream. The one on the right has some pock marks and a couple black spots and maybe what looks like scab. The other six fruitlets are clean. Any idea what is affecting the one fruit? Should it be removed? Thanks!

[TheVeggieProfessor]

Veggie Professor,
Root inefficiency caused by dry, chilled soil, commonly causes episodic nutritional deficiencies of zinc, copper, calcium, sulfur, etc.
The small or misshapened leaves are very susceptible to infections.  I see mostly anthracnose--- grey-black --- and a few mango bacterial black spots--- coal-black.

Use mixed fertilizers with all the micronutrients, and use gypsum, and spray with copper and other micronutrients.  Avoid the 0-0-52 fad.

Thanks for your response Har. I'll get right on it!

[MJ88]

I noticed when transplanting some of the little roots on the bottom kd the plant and some on the surface of the soil are real dark brown almost black, but they don't feel mushy and/or come off easily when I pull on them. They seem to be still in there pretty firm. But my leaves have looked a little yellow and curling. I'm wondering if it could be root rot, the pictures of my plants are a couple posts up. From what I'm reading black roots mean rot, but they don't smell and aren't mushy, they just look like dark little feeder roots. If anyone has any thoughts on this, I could really use a second opinion, I don't really wanna take it out and sterilize the roots with peroxide and replant and all that if I can avoid it, I just transplanted to a new pit yesterday. Someone please get back to me, it would be greatly appreciated.

[Guanabanus]

MJ88,
The black mold-like fungus on the outside of mango new growth is largely harmless.  And not related to root conditions.

The root condtion sounds normal.  Did you cut the circling roots?

[Guanabanus]

Fliptop,
Spray with a Copper product.