Been growing greenhouse tomatoes for about 30 years (in the UK), usually grow Shirley from seed, always in growbags. I've seen most tomato diseases over the years either on my own plants or been given material to diagnose. This year is different though. The plants started in pots as usual, looked OK and then first the leaf edges and then whole leaves turn white and die. Initial thought was nitrogen deficiency so I gave a high nitrate feed. The plants certainly took up the nitrogen and have grown but the necrosis continues on the fully expanded leaves. A few Gardener's Delight started the same way are not showing any issues now - although one or two might have had a little issue early on.
Photos attached. Comments welcome.