When I visited Kanchanaburi, I stayed in Pang Tru at my friend's parents' house. Her parents were rice farmers, and on the second morning, I was invited to join one of their employees when he was going to deliver sacks of rice. At this time (mid-July), most of the rice was dry enough to be put in sacks and sold to a rice mill or some shops.
On the right side of the picture, you can see a machine used for harvesting, but many farmers still harvest by hand. I also saw this when we were driving around among the rice fields.