Top Tom Tip
Many years ago my old friend and presenter of Gardeners' World, the late Arthur Billitt gave me this tip. Prior to presenting Gardeners' World he worked as a research aggri chemist for Boots.
He said they had conducted trials on tomatoes and it was found that the size of the bottom truss was influenced by when the seedlings were potted-on. Tomatoes should be potted-on immediately the first pair of seed leaves have straightened out and for each day's delay in doing this reduced the size of the bottom truss.
Plant them deep with the seed leaves resting on the compost.