Re: Dioon edule leaf collapse
Posted by Tom Broome on 6/11/2011, 2:27 pm, in reply to "Dioon edule leaf collapse"
: One of my 15 gallon Dioon edule
: recently pushed a beautiful flush of
: sixteen leaves. A day after
: admiring its perfectly symmetrical
: crown of leaves, I noticed that the
: leaves were leaning slightly in one
: direction. Upon inspection, it
: appeared that the petiole / caudex
: connections were soft and unable to
: hold the leaves up firmly. I am
: assuming that I may have a root rot
: problem and the plant is unable to
: take up enough water to keep the
: leaves turgid in the heat of the day
: (95-100 degrees). The leaves appear
: normal in the early morning. Two
: days ago I applied a Subdue
: fungicide drench. Can you recommend
: anything else that I should be doing
: to prevent total plant failure?
: Should I consider removing leaves?
How often are you watering the plant? I have seen this many times when it gets as hot as it is right now and the plant doesn't get watered but a couple of times a week, or less. There are signs that tell you that water is the problem. Since the leaves look decent in the morning, the plant is keeping up with what it needs until it gets so hot that it can't pump enough water into the leaves. You may think there could be rot, but unless you have seen some on the stem, I would say the most likely chance is just that you would need to water it more often when it is as hot and dry as it is.
Dioon edule usually doesn't have this problem all the time, but there are quite a few cycad species, like Encephalartos whitelockii and E. bubalinus that will have theor new leaves just drop before they even have a chance to harden up. I tie the leaves together and support them with a stick, or in the case of a huge whitelockii, I use a 1/2 inch metal conduit. In these cases, once they harden up for a month or so, they will hold their leaves erect and I can take down the support. I'd try something like this because those leaves can pull away at the apex and harm the plant.