Doesn't appear to be disease on lower leaves. Is it getting worse or staying the same? Likely mechanical damage or brief water shortage.

New growth looks fine.

Been like that for two weeks, rainy season here, groundi is damp but hot during the day, 30celcius.

Should i remove the affected leaves, more water or leave it?

If it rains/pours every other day, I would not water it. I would mulch the base of the tree instead. I'd not remove the affected leaves (not yet).

When did you plant it? If it's not too long, you may want to shade it to lessen the heat intensity for a few weeks.

Just curious, what variety is that mango tree? What province are you in the north?

Mango is one of the easiest trees to grow in Thailand.

I'd like to add that if you post in the Tropicals forum on this Gardenweb, you are likely to get more answers. Questions about mango trees are posted fairly often.

Thanks, im near udon thani, sorry, i dont know the variety. I planted it about 9 weeks ago. It is at the end of the rainy season so it is raining oncë each 5 or 6 days now.

Thanks, im near udon thani, sorry, i dont know the variety. I planted it about 9 weeks ago. It is at the end of the rainy season so it is raining oncë each 5 or 6 days now.

You are way up there in the northeast. If your mango tree is in full sun all day, I feel that you should protect this little tree by mulching about 3-4 " thick and about 3 ft in diameter at the base of the tree.

E-san is known for hot and dry weather, giving it some shade in the afternoon (1 - 3 pm) for couple more months is not a bad idea. Water it (if no rain) deeply once a week should be fine if your tree is mulched. Otherwise, you may need to water it more often.

I don't think you tree looks sick. It probably is still adjusting to a new home and from being in the heat. General speaking, soil in the Northeast is not the best andt the heat is also harsh. Baby it a bit does not hurt.

Check GardenWeb forums' main page. Go down to the bottom third, look for a Column labeled "By Name of Plant" and go down that column to Tropicals. That's where you want to post your tropical fruit/tree questions.

Hopefully, you planted a sweet variety or the one that is eaten green and not sour. I don't think there is a name of the latter in English.

Good luck

Several forums for tropicals.

This one = tropical fruits
http://forums.gardenweb.com/forums/tropicalfruits/

Here is a link that might be useful: tropical fruit forum