A very common problem in the wet tropics is bacterial wilt. This affects any plants in the Solanaceae family, tomatoes, capsicums and eggplant specifically. The almost wild cherry tomatoes seemed more resistant although last year even they did not do well, but that could also be because the dry season was very wet. I think we are overdue for a good dry season so I have planted a lot of vegetables in anticipation.
I started a new bed along the back fence in order to practice crop rotation and also imagined that if I grew them in pure compost, the problem would not occur. Wrong - I bought a six pack of "tropic" which is supposed to be resistant and they all keeled over, along with all the eggplant. There are a few cherry tomatoes that seem to be surviving. Funny though that I have an eggplant that has been growing for over two years in the front garden, and although it doesn't look that healthy it just keeps producing. I wonder if it has generated its own resistance (I have saved some seeds) or if there is no bacterial wilt in the front garden.
Gardening in the tropics is certainly an adventure. Next on my list is a way to find out how to stop the little green grasshoppers. Garlic chili spray seems to have slowed down the tiny green caterpillars that made lace of every green leaf in the vegetable garden, but the grasshoppers seem to like the taste!