I saw an interesting segment on a show called "How It's Made" on television last night. The segment was about how they grow commercial hothouse tomatoes.
They germinate and grow the hybrid seedlings in coir blocks about the size of a brick. The producing plants are replaced yearly with new seedlings in the fresh coir blocks. Each seedling has a string hanging from above which it grows up. The top tip of the seedlings produce blooms and grow up the string about eight inches per week. When the plants are about eight feet tall, they have blooms at the top of the vine and ripe fruit five feet below on the same vine.
When the vine's reach eight feet in height, they start lowering the string eight inches per week and simply coil the vine at the bottom as the top grows. At the end of one year, each vine is about thirty feet long with most of the vine coiled on the floor below. Those vines are then removed and replaced with new vines.
All the temps, humidity, light, and nutrients are computer monitored and adjusted as required to maintain the optimum growing and production conditions.
The tomatoes were the cluster type with five or six fruit on each cluster. Each fruit was perfect in appearance. I would suspect they taste like high quality cardboard, but they sure are pretty.
Another interesting thing that I almost forgot is the fact that they maintain many bumblebee nests in the growth/production areas to keep the blooms pollinated.
Ted