I can't think of anything that could be better to foliar feed a pumpkin plant with than seaweed/kelp and humic acid. The two work synergisticly together to provide a lot of benefits to the plant. Improved laterally branching, cell elongation, leaves that stay healthier longer and improve fruit set are just some of the value that comes from seaweed. Those values are improved further when humic acid is applied with the seaweed/kelp.
This evening I did a foliar application of RAW Kelp along with RAW Humic Acid.