Double Mastery Weekend! Until November 28th at 9:00 PM PST, all FarmVille players will receive double mastery experience for all crops they harvest. Here's a quick list of one day crops you can plant that will let you take part while you chase your holiday plans! (Trees are included in the Double Mastery bonus.)
You should go for the crops which take minimum time to grow so that you can actually harvest more crops. As I can see that the more crops you harvest the more double mastery you get.