Your Sago Palm is actually not a palm tree at all but a member of the Cycad family, a tropical plant that needs shade from the hot afternoon sun. It looks like your plant got a bit too much sun or heat. This slow growing plant likes a slow release plant food at the start of cool weather and likes extra water when the temperatures are hot. You can also grow it as a houseplant. I think your plant will survive as the sunburn is minor. Keep growing, Marianne Binetti