My Pinus Pinea, the first plant I tried to train as a bonsai, is not really healthy.
Since 4/5 week I noted that some needles near the buds (the tree is still in his jouvenile foliage habit) were dry, and as time goes by the situation is becoming worse.
The pre-bonsai is in the same substrate from three years, my intentions were to repot it the next year because the soil seem in good state. Its position is in full sun, and I gave it water only when the soil is dry to the touch.
Sorry for my bad english, I'm from Italy.
Now I post some photo

Welcome, I don't think there is much wrong. It looks to me like old needles are brown. I don't know the species, but most pines will lose old needles like that. I wonder if it needs some shade in the middle of the day, though. I would be adding fertiliser every 2 or 3 weeks. Use one with low nitrogen.
Geoff.

I changed the position to a more shaded one yesterday and I also bought a specific fertiliser, but a great number of the dry needls are ON the new buds produced this spring

you look at the end of the shoot in pic 3 (last picture) than you can see that it has been pruned, so it could be a bit of dieback.

jaimin

Have you been pruning? It could be die back but difficult to tell from the pictures.

The last pruning I did on this tree was in March, and some of the ill foliage didn't exist at all that time. Now I've used a sistemic antifungal treatement.
Thanks for your interest
Mirko

Ok, Mirko, I am not sure that will help, I think it will grow out. I don't think there is any problem and as the shoots grow it will go.
Some pines when pruned will show brown tips, and this may be one of them.

All I know is that Pine is probably the worst plant to start with. I tried to bonsai a Mugo pine and it did the exact same thing. It browned all the needles until it died. I don't believe pine likes to be pruned during the warmer months so it would probably be wise to prune when the plant begins to go dormant. Also, you will have less chance of disease if you prune in the late winter or early spring.

Pinus mugho is one of the more difficult species. However the plant in question is very small and only a seedling. Once a bit bigger it may well be better. It needs to be left to grow and not pruned for 2 or 3 years then work can start, and the best place to grow on is in the ground

Pinus Pinea is relatively simple to train, because in his youvenile habitus it don't produce candles, the needles are very short and it's more prone to produce buds on the old wood than other Pinus. If you look carefully the fourth shot, you could see the die back along the stem, bat also that the retroceded bud born after the pruning is partially ill. I think it could be a fungal desease, the last years this pine was really vigorous and with only a very little die back on the pruned branches. Now the plant is in a more protected position and treated with tebuconazol trifloxystrobin.

I'll wait for the evolution of the desease (I cross my fingers), if someone has others ideas thanks for the help!