On the 12th August in the news they provided a link to a sneak peek. In that it mentioned the following...
Event resources: "Pumpkins" can be used to obtain several items during the Event
Pumpkins spawn on the island can be obtained through the following adventures as reward:
Roaring Bull, Mother love, Mad Mary, Gunpowder, Surprise Attack, Bandit nest
Do you know if they will drop in loot from SA and BN?