What's wrong with my Mango seedlings? (Pics inside)
I'm trying to grow some Mangoes from seed, since NO ONE has ever tried to in my region, and there are zero production of mangoes in my country --Algeria-- hence I can't find any expert and I'm still a newbie in the field.
I'm growing all of my seedlings in my Balcony, which I covered up to 2 meters height, which means there's only partial shade that can reach them except for about 40 mins daily where the sunlight can get through directly to them.
I've had a problem with some kind of green flies or mosquitoes or whatever they were, and I applied a pesticide and got rid of them, but right after that I suffered from a lot of spider mites, which killed 2 citrus grafted trees and almost 90+ citrus seedlings grown from seeds as well. No pesticides seem to work so far for these latter, and only after I applied some water mixed with sulphur powder, they seemed to decrease dramatically. (The Sulphur trick was suggested by an old farmer. There are a lot of spider where I live though)
I also over-watered the mix of sand and potting soil for the first time of the transplantation and kept watering regularly, even though I didn't see the soil being dried and it was always moist, and I'm not sure if this is a symptom of root rot, and if it's the case, should I transplant them to something drier?
I also wanna know if the curling of the other leaves is caused by a spider mites' infection as well? Could it be the case? What do you think guys?
By the way, the other seedlings do have some blackening spots as well at their ends, and I'm worried if they'll follow the same route. I've noticed like a scratch on one big leaf of a healthy seedling and it looks somehow transparent, as if something was suckling all the water out of it and soon gonna pierce it, though I couldn't spot any mites on board :/
Do you think it's a good idea to remove the blackening leaves?