Can anybody help diagnose this problem i really think its ph but want some info before i buy a ph tester the only other thjng as i said is heat from greenhouse or now thinkinv that it could be spillage on leaves and the sun has magnified it through the leaves please can anyone help
Without knowing the pH of your feeds and run off we're only guessing. More times than not it's a pH issue, which is why we always start there. Eliminate the obvious first. If it's only the lower leaves they could have been touching the soil, which can cause that. That's why I asked for pictures of the whole plant, so we can see what the rest of the plant looks like, if it's healthy or not.