I have a greenhouse filled with tomato plants, but with the dark and rainy weather we have had in Québec this spring the plants have a tendency to elongate rather than enlarge. I would be very happy if I could find a way to reduce their growth upward (without completely stalling them) and instead encourage fruiting. I have thought of growth hormones, and have found information on auxins encouraging fruiting, but not on their effects on overall growth. Some extra information on my plants: They are about 1.2m to 1.5m tall right now and have started developing their 3rd-4th cluster of flowers. They are grown in soil trenches and pots, not in bags or hydroponic systems. I would be grateful if anyone has thoughts to share on tomato cultivation or growth hormones, and could help me with my problem. Thank you :)
It sounds like a better investment might be lights, and a change in fertilization. If you've got flowers, you need to be feeding a lower N, higher PK ratio to the plants. Auxins are a possibility, and a lot of research has gone into them (and coayudivants the Gibberellins). This is a good starter article on it.
Thank you for pointing me to this article, it is very interesting :) I might try auxins next year, just as an experiment. For my problem this year, I've opted for taking the most problematic plants out of the greenhouse. The shock of the colder weather seems to have sufficed to reduce their elongation and instead they are enlarging and producing thicker stems.
Horizon, have you experimented with regulatable greenhouses? Tomato is also cultivated under plastic in Ecuador's highlands (for different reasons - they suffer sunburn here), but the greenhouses have sections of wall that can be rolled up to allow cooler temperatures in to the plants when they're looking leggy or need to cool down....
