Thursday, April 23, 2009

Prizehead Lettuce

The three large plants in this ebb and flow system are prizehead lettuce. I am always on the lookout for seed varieties that I have not tried and came across this variety recently.

It was apparent to me shortly after the seeds germinated that this one was a winner. It came up rapidly and very quickly developed the first true leaves. The seedlings remained compact, and developed a decent root system in about two weeks.

A recent article I read made sense of a problem I have been having with lettuce that heads, and even some leaf lettuce. There is always a slight amount of tip burn on my heading lettuce. It is easy enough to trim off, however it was driving me up the wall trying to determine why this was happening.

Typically tip burn is a result of a lack of calcium, and I was supplying plenty of fresh nutrients. In an attempt to overcome this problem I decided to increase the TDS level to above the recommended level for lettuce. That, it turns out, was entirely the wrong thing to do.

The article I read was written by two university professors and it stated that tip burn is more prevalent in summer grown lettuce. The reason being: that summer grown lettuce grows so fast that the plant can not get calcium to the new growth fast enough to keep up with the rate of growth. The result of the rapid growth is tip burn from lack of calcium.

Apparently, my indoor conditions are causing the lettuce to grow too quickly. How about that? Damned if you do, and damned if you don't.

All of my growing has been moved to the greenhouse, and I have reduced the TDS level in the ebb and flow system containing this lettuce. So far, there is not a sign of tip burn on these plants. When I resume growing indoors in the fall I will try reducing the photoperiod to 13 hours, and reduce the TDS level to 560, which is the low end of the recommended range for lettuce.

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