My tomatoes leaves are yellowing. It is on a drip system and is watered 2 times a day for 5 minutes but the water runs straight through... any suggestions
Certified GKH Gardening Expert
If it were just the yellowing, I would have less concern. I also see black and grey in there too. That's no good. There is a fungal infection present.
Do these plants have a chance to dry out between watering? Heat is fine, since they are tolerant of high temperatures, but letting water remain constantly wet will not be. This could be the cause ,especially, since there is a drip pan. This will hold extra water.
I would wait to water until the soil is pretty dry, almost all the way through. This can be measured by weighing the difference between a fully dry pot, and a fully saturated pot. When it gets close to the weight of the fully dry pot, then it would be a good idea to water. They can handle quite a bit of heat and dry.
You will want to, either, use a handful of DOLOMITIC LIME and WETTABLE SULFUR, or a pre-prepared spray fungicide such as at this link: https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm