Localized yellowing, curling, rust spots, dying!

Hi guys - here are some pics of my leaves and plants. They seem to be doing something similar to nutrient burn, but it doesn't affect all the leaves, or even a group of leaves. Not just young ones, not just old ones.

About half a week back I sprayed some pesticide on it to get rid of spider mites - sprayed permethrin twice over 2 days. The spider mites seem to have gone, but now this! It's affecting the whole group that I sprayed, and only some locations of the plant. Could residual chemical on the leaves be causing this, or something more fundamental?

Sounds like you could use a good flushing. But it could've been an over application of that permethrin. The way the leaves are dying doesn't look like a typical die-off...at any rate, a flush with warm water can help get rid of a possible buildup and maybe straighten out any ph problems which will also help the plant metabolize impuritys, such as the pesticide.

Warm water...wait a half hour, repeat.

^Agreed, that's what I was going to suggest. There's some kind of problem with your medium, and rather than guessing what it is, it'd be easier to flush, and give it a fresh start.

Can you please be a little more descriptive on the flushing part. I think my plants are suffering from the same thing and thing they might need it too.

Basically, what you are doing, is rinsing all the built up nutes and waste from the soil. It takes about 3x the pots volume, to accomplish this. For example....if your pot is 5 gallons, you'd have to pour 15 gallons of water(PH properly) through the soil, washing all the waste out the drainage holes at the bottom. At first, the runoff will come out quite dirty, and will be practially clear, by the time you are finished. This gives you a nice clean growing medium to start with, and the plant will thank you for it.

P.S. The key, is to make sure you flush the entire medium, evenly. If your soil is pretty dry, it works best if you give it a really heavy watering, wait a 1/2 hour or so, for every to get evenly damp, and the waste dissolved and loose, then come back and flush. If you just go and pour in a pile of water, hastily, most of it will run down along the edges of the pot, and will leave you lots of 'uncleansed' areas, so to speak.

Hey guys thanks for the advice. I flushed yesterday (flush, wait 30 mins, flush again). Water was yellow at first then turned clear eventually...the topsoil was foaming as well so I just flooded the pot and let it overflow/run off. They're back on my balcony now (under shade since it looks like it might rain here in Bangkok today). Will report back over the next few days. Thanks again!

Another question - slightly related - about trimming leaves. For the leaves that are damaged, should I prune? If yes, do I cut the whole leaf, just the affected blades, or the affected parts of each blade?

Thanks guys!

As long as they have good dark green parts then they are producing sugars. Keep them until they die.

Flushing is absolutely the way to go but don't forget to check your water. Hard water with high TDS (total disolved solids) is often the real problem and the deficiency you see is the secondary problem. The real kicker is that if you don't check the water and it is hard or somehow not good for your plant, your flush will compound the problem and you'll be left scratching you head. This was one of my 1st grow mistakes. I've learned that PH and H2O are the first things to check when problems surface.

Good Luck