greenhouse-tomatoes: Questions.

I have a couple of questions that requires expert input.

I’ve always heard that, when pruning lower leaves, one should remove no more then three leaves at a time to reduce stress on the plant.

My question about this is; who says? Some of these lower leaves, although still green, look like they are adding stress to the plant. I would like to remove leaves up to the first cluster with tomatoes on it. This may require the removal of 6 to 8 leaves. Has anyone tried this procedure and if so, what were the results? What negative affects should I expect by doing this?

Next question has to do with temperature. I believe 64 degrees F is the magic low number. I have a hydronic heating system so the heat is pretty uniform throughout the greenhouse. In the past I’ve gone as low as 55 degrees F with no negative effect on fruit set but the hot water pipes are within inches of the root ball/buckets. I’ve recently learned that lettuce can be better controlled by monitoring nutrient temperatures and not so much ambient temps. Given that lettuce is all leaf, I realize that this practice can not be strictly applied to tomatoes. I’m wondering to what extent it can be applied. In other words, if we heat the solution and or the root ball to a suitable temp, how low can the ambient temps go? Then, what is a suitable root temp? Another question is why 64 degrees? Is it for the benefit of the flower, stem, or leaves?

Perhaps the researcher that came up with that number was basing it on what he thought was a comfortable temp for him to be working in the greenhouse!!

Any input would be great.

Michael Pierce

M & R Hydroponic Farms