Caring for Neps with Damaged Roots?

[Stranger]

So long story short I recently received a robcantleyi x hamata with a relatively fragile root system that I suspect was damaged during the whole unpackaging/potting process. It's been about a week and the growth tip is visibly progressing but the bottom most leaf is now yellow. Probably due to transplant shock but I'm slightly paranoid about this. What signs are generally seen that indicate root damage/loss (similar to root rot I'd guess?), and what steps can I follow to take special care of this plant, up to and including use of PGRs?

At the moment temperature is a bit higher than I'd like to see, greenhouse is currently ~30-35 C during the day and ~20-22 C during the night. Humidity is 60% at minimum though, typically closer to 70 or 80%. Soil is orchid bark, perlite and chopped sphagnum in about a 2:1:1 ratio and drains reasonably well. As for light all I can say is that it's under 50% shadecloth which my other neps seem to like.

 

[Bio]

The plant will probably be just fine; Nepenthes are tough plants. However, the temperature is too high during the day. If you can lower the day temperature, the plant should grow just fine.

 

[theplantman]

what steps can I follow to take special care of this plant, up to and including use of PGRs?

PGRs are a bad idea for any purpose other than controlling the size and finished appearance of a nursery crop. They mess with plant hormones and for the most part would not produce additional root growth. There is one PGR that *may* have the unintended side effect of increasing drought tolerance, but at the cost of limiting heat tolerance (it forces stomatal closure). Plus, the concentrates generally run in hundreds of dollars.

And IME they are the easiest way to completely damage your plants, if not outright kill them. PGR damage is one of the worst types of damage because the hormones reside inside the plant, so you can't wash them out like you can with overfertilization or other problems. Once you've applied too much, your plant will remain dwarfed or otherwise affected for months.

Examples of the trouble you can get into with PGRs:
http://www.ces.ncsu.edu/depts/hort/floriculture/Rx/PGR Overdose Guide.pdf

Overall, the best course of action with a stressed plant is not panic and overreact. Maintain average soil moisture, good light, and high humidity. If you notice wilting, reduce transpiration by (1) reducing light and temperature or (2) clip off pieces of leaf until the plant no longer wilts. This balances the shoot ratio to the root ratio. (3) Light foliar feeding will reduce transplant shock by providing the raw materials for root hair production. If your plant is nutritionally limited, it can't recover from transplant shock as well as a healthy plant.

 

[theplantman]

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[Whimgrinder]

So long story short I recently received a robcantleyi x hamata with a relatively fragile root system that I suspect was damaged during the whole unpackaging/potting process. It's been about a week and the growth tip is visibly progressing but the bottom most leaf is now yellow. Probably due to transplant shock but I'm slightly paranoid about this. What signs are generally seen that indicate root damage/loss (similar to root rot I'd guess?), and what steps can I follow to take special care of this plant, up to and including use of PGRs?

At the moment temperature is a bit higher than I'd like to see, greenhouse is currently ~30-35 C during the day and ~20-22 C during the night. Humidity is 60% at minimum though, typically closer to 70 or 80%. Soil is orchid bark, perlite and chopped sphagnum in
about a 2:1:1 ratio and drains reasonably well. As for light all I can say is that it's under 50% shadecloth which my other neps seem to like.

I am only going to address the temperatures in your greenhouse at this point: nights of 20-22C and days above 30C are FAR too hot for highland type Nepenthes. That plant will not last long in those temperatures. You will disrupt the plant's metabolism completely and it will gradually (or not so gradually) decline and die. Temps should be closer to 12C at night to a maximum of 27C in the daytime, and for short periods only, if possible. (try to limit daytime highs to 26C or less, as much as possible)

The plant you have is bred from species native to an upper elevation rainforest where humidity is always high and a day that gets much warmer than 75F is regarded as "hot".

 

[Dexenthes]

If some of the roots were truly disturbed or broken during shipping then the best thing to do is to leave the plant be and let it do its thing.

The less you move the plant, or fuss with it, the quicker the plant will resume growing and establishing new roots. Though your temps are not ideal for a highlander by any means, the heat tolerance of this specific cross is not well known as of yet. It could very well withstand intermediate temperatures or lowland temperatures for short periods of time, but to see the best growth and health for your plant it would be best to aim towards the temperatures that others have suggested.

 

[Stranger]

Thanks for the advice guys! Temp definitely isn't the best, I moved to a different greenhouse recently and this is its first summer. Evidently my ventilation was inadequate. Better cooling/ventilation was ordered a couple of days ago, so hopefully that issue will be fixed in the next week or so.

Theplantman, will definitely stay away from the PGRs, thanks for the link as well! I mentioned PGRs because elsewhere it was recommended that a low dose of IAA or similar auxins might be beneficial, like what's sometimes used in tissue culture. Out of curiosity, what do you think the effects would have be here if I'd taken that advice?