Needed Help with the Pine

[Ali Raza]

Hello Everyone. I am training my pine tree for bonsai. Some of the old needles on the pine began to appear yellow in color. Some of them started to turn brown from the base. The new growth on the pine is growing pretty well. This problem is present only in lower branches of the pine. I was checking on the internet and came across dothistroma needle blight. I was wondering if some one can identify whether it is dositherma or any other problem and what will the possibly solution. I am little confused and worried right now. Some of the pictures are attached herewith.

 

[Adair M]

What kind of pine? How old are the “old” needles?

I didn’t see anything concerning. Old needles do dry up, turn yellow and brown, then fall off.

 

[Ali Raza]

What kind of pine? How old are the “old” needles?

I didn’t see anything concerning. Old needles do dry up, turn yellow and brown, then fall off.

Adair M it is Afghan Pine almost 9 year old. Needles are more than year old.

 

[Shibui]

Pine needles (and most other evergreen leaves) are only efficient for a few years. Each spring new needles grow. After 2 or 3 years the tree sheds those older leaves because they can't keep converting sun and water into plant food. The newer leaves have taken over the job of harvesting sunlight and so the cycle continues year after year.
It is hard to guess whether the older needles on your tree are 2 or 3 years old because we don't know how or when you pruned it.
Dothostroma usually shows up as orange or brown bands across the needles. There are a couple in the last photo that might be affected but there are other possibilities.
Nutrient deficiency: lack of Nitrogen can cause older leaves to die sooner than normal. N can be moved in the plant so in emergency trees can move available N to new shoots to help grow fresh leaves while older leaves die. Have you been feeding this tree? I think this may be one of your recent collected trees? Lack of roots can cause some older leaves to die in order for the tree to balance roots against leaves.

The new shoots look very healthy so probably nothing to worry about. If you are concerned about fungal infection you could spray fungicide. I think copper sprays are effective against dothostroma and will not hurt the tree even if it is not infected.

 

[Ali Raza]

Pine needles (and most other evergreen leaves) are only efficient for a few years. Each spring new needles grow. After 2 or 3 years the tree sheds those older leaves because they can't keep converting sun and water into plant food. The newer leaves have taken over the job of harvesting sunlight and so the cycle continues year after year.
It is hard to guess whether the older needles on your tree are 2 or 3 years old because we don't know how or when you pruned it.
Dothostroma usually shows up as orange or brown bands across the needles. There are a couple in the last photo that might be affected but there are other possibilities.
Nutrient deficiency: lack of Nitrogen can cause older leaves to die sooner than normal. N can be moved in the plant so in emergency trees can move available N to new shoots to help grow fresh leaves while older leaves die. Have you been feeding this tree? I think this may be one of your recent collected trees? Lack of roots can cause some older leaves to die in order for the tree to balance roots against leaves.

The new shoots look very healthy so probably nothing to worry about. If you are concerned about fungal infection you could spray fungicide. I think copper sprays are effective against dothostroma and will not hurt the tree even if it is not infected.

Bundle of Thanks Mr. Shibui. This is Afghan pine collected from the wild last year. It was growing in very hard clay. I potted in well draining pumice and did little root pruning. It was fed with organic fertilizer and liquid fertilizer after 10 days. But old needles were turning yellow, crispy and fall when you just hold them. The new growth is growing well. I was little confused about the old needle thought that it might be some kind of viral or fungal attack.

What about sulphur based fungicide spray ?

 

[clem]

hello, i advise you to remove the "Brown" suspect needles. And just to watch out if some other needles turn Brown in the coming weeks. The 3 first pics are not alarming IMO but the last pic show needles that seem to have had fungus attack. So it is better to remove them. If it is something serious, the disease will progress during the coming weeks.

Do you have some jin liquid (lime sulfur solution) ?

 

[Ali Raza]

hello, i advise you to remove the "Brown" suspect needles. And just to watch out if some other needles turn Brown in the coming weeks. The 3 first pics are not alarming IMO but the last pic show needles that seem to have had fungus attack. So it is better to remove them. If it is something serious, the disease will progress during the coming weeks.

Do you have some jin liquid (lime sulfur solution) ?

I do have sulphur based fungicide powder. What you say if mix that in water and spray on the needles ?

 

[clem]

I think you can do it, but protect the soil. As long as the green needles stay green, it isn't a problem, imo. Remove the Brown needles

I've already had fungus attack in spring (May) when températures get warmer and the progression was very fast : in one week or less new needles were attacked and getting Brown (like burned)..

 

[Shibui]

Sulphur based insecticide powder won't hurt the tree but may not be effective against fungus. Insect is different to fungus. Real fungicide would be better but the condition does not seem to be severe at the moment. Often it will disappear without any treatment or just by removing affected needles as Clem suggests.
If it gets worse definitely use an approved fungicide treatment.