John's Tomatoes

A friend of mine called me saying there was someting wrong with his tomatoes, he said "they have brown spots all over them and are dying" He brought them over and I suspected some kind of fungal disease. The main problem was the sprinkler system he'd set up to water them. Watering them in the evening via a sprinkler and leaving them all night wet make it easy for fungi to get a hold.
The best way to water tomatoes is via the roots straight into the ground - and if you already have a sprinkler set up it's best to water in the morning so they can dry out during the day.
I saw book suggesting to cut the bottom out of a soft drink bottle and invert it into the ground and filling it with water allowing water to slowly trickel into the soil, might be worth a try if your soil doesn't hold much water. It also helps to leave some room between plants to allow some air flow. As it heats up in the tropics you can squeeze another month out of tomatoes by sheltering them from the high sun. Something rigged high will allow the morning and afternoon sun in and provide shelter in the heat of the day.