Hi, 

Can you provide us with some more information. What are they planted in? (peat-based potting mix, coir-based, fine pine bark...?) 

The pH or the acidity level of the mix might be interfering with nutrient absorption or, depending on how recently you started applying fertilizer, maybe the nutrients haven't been absorbed yet?

Daily watering sounds excessive for this weather (maybe once the plants were older and the weather consistently hot it would be more appropriate). It has been dry but the night time temperatures have been fairly low still. Make sure you are feeling the soil a few inches down into the pot to determine if they really need watering first. Does the potting mix dry to at least a couple inches down between waterings? Do the containers have drain holes or trays underneath that is holding the water?

The plants are possibly too crowded for pots that size (if those are winter squash in the third photo, probably only one of those would be suitable for a container that size). This is not an immediate issue as the plants aren't competing with each other just yet, just a longer-term issue that might reduce yields or make the foliage more disease-prone once it becomes crowded. 

For now make sure the the soil is being monitored for water needs first and you can pick off the browning or dead foliage. Just keep watching for other ailing symptoms and feel free to respond with additional photos along with some more information. 

Emily