Who wants to volunteer to grow a fig-leaf gourd accession for GRIN?

Hello, all. I need some advice. My plants are growing, albeit slowly. I had planted 2 seeds per hole thinking that there would be some loss. But all the seeds germinated and so there are two plants very close to each other in most spots. Some plants seem a little more yellow than others. The soil is a sandy loam and has not been amended. Our highs have ranged from the low 70’s to the upper 80’s, with light showers from time to time. I’ve been watering about once a week. In another post, @ThomasPicard mentioned that they like water:

Should I give more water? Some fertilizer? Should I thin to 1 plant per spot? In this instance, I assume that we are trying to get seeds without much selection pressure. Thanks for your help!