I've had a chili bush I grew from seed for about a year now, and it's finally growing into something resembling an actual bush (rather than just a seedling) and it was going great until the last few weeks.
The new leaves are starting to kind of crinkle, and the most recent new shoots look as though they're dying entirely.
In spite of this it's bravely trying to grow a pepper on it!
But yeah - couldn't see any pests (other than the stupid things that ate the leaves further down the plant a month or so ago which are no longer affecting it) so am I looking at bacteria, fungus, virus, or deficiency here? Or something else?!
Location: Brisbane, Australia. It's late Summer here. Soil is clay, although clay breaker has been used occasionally on it, and the grass nearby has been fertilised recently.
Here's some pics in case it helps:
EDIT: Accepting diagnosis answers is tougher than I envisaged!
So, since originally posting this, I refertilized (herb/veggie fertilizer) which seemed to only very slightly help. Then, we had a cyclone, which dumped 150+mm of rain onto the soil, which also helped a bit, then I cleared the grass in a 50cm diameter circle away from the base, added weed control sheeting, topped with a little new soil, and fertilized with some stuff that had higher calcium concentrations in it than most fertilizer. Result is:
Doesn't look completely better, but seems a lot less unhappy. So it's really hard to tell which of the three things it was that made the most difference, and I won't really know unless the plant starts to get worse again. As it is, it seems like the new shoots are much less curled (but not completely flat) so... yeah. Here's a pic of the whole bush showing the base etc:
EDIT: Latest pics after drenching in eco oil and pyrethrum a week or so ago.
As of last week, this is what the worst affected parts of the plant were starting to look like:
I finally tried absolutely drenching the plant in eco oil and pyrethrum (both sides of all the leaves, all trunk/stem surfaces... to the point it was dripping liberally off onto the ground underneath it.) A week or so later, it started to look like it was throwing out new leaves and these weren't affected, so I trimmed off the older damaged foliage etc, and this is now the result:
It... certainly is very suggestive that it might have been a pest that was not easily seen... will wait to make sure it's still on the right track, but all things going well I'd say this will finally get a resolution in a few weeks or so... capsid guy is looking good so far :)
EDIT: update after a year of trying to nail this persistent sucker.
So my latest update to this is that none of the above appears to have made a lasting difference. After a lot of reading up and experimenting over the year I'm almost certain now that this is a virus, and I suspect it is spread by midges or similar. Spraying with white oil and pyrethrum not just on the chili bush but also on surrounding grass, plants, vegetation, and weed reservoirs appears to dramatically slow the spread of the disease from reaching new plants, but you need to keep applying the spray every two to four weeks or it wears off and the bugs come back, and then a few weeks later so does the curl.
If you give it fertilizer and make it generally happy with water and light and warmth etc it seems to be able to outgrow small infections reasonably well, but once it starts to get too infected you have to basically kill it and burn the bush to prevent spreads. The bush in the images above is now sadly cut off to the ground and burnt, though the stump has started to sprout some leaves so we'll see if the below-ground portion is okay or not.
The Bhut Jolokia and Butch T chili plants I also grow are also possibly to be affected by the virus, but not as strongly.