MSU research articles

[Sun rm.N.E.]

I found this website with MSU research articles interesting. Some of the articles also have good pictures

http://www.hrt.msu.edu/faculty/Runkl...m#Publications

Just an example of an abstract:

Container Opacity and Media Components Influence Rooting of Potted Phalaenopsis and Doritaenopsis Orchids

M.G. Blanchard and E.S. Runkle
Department of Horticulture
Michigan State University
East Lansing, MI, 48824
USA

Keywords: chunky peat, coconut, fir bark, translucent pot, vegetative growth

Abstract
Two experiments were performed to determine the effects of container opacity and different media components on rooting and vegetative growth of several clones of Phalaenopsis and one clone of Doritaenopsis hybrid orchids. Doritaenopsis White Moon and Phalaenopsis Sharon Bay were grown in 12 cm translucent or opaque pots containing a bark-based media. After 30 weeks at 29°C, plants in opaque pots had formed >7 roots outside of each container,whereas <2 roots per pot had developed outside the translucent containers. In a second experiment, Phalaenopsis Brother Showpiece, Brother Wild Thing, and Pink Twilight were grown in opaque 12 cm plastic pots containing different ratio of medium-grade Douglas fir bark, medium-grade coconut coir, long-fibered sphagnum moss, coarse perlite, chunky peat, and fine-grade charcoal. Plants were grown for 33 weeks at
29°C with a maximum light intensity of 300 µmol m−2 s−1. In general, plants grown in a medium consisting of 1:1 (by volume) chunky peat: perlite or 2:1:1 perlite:chunky peat:coconut coir had fewer aerial roots than plants grown in a bark-based or 1:1 perlite:charcoal media. In addition, plants grown in the chunky peat: perlite mix or chunky peat:charcoal mix had the greatest increase in leaf span compared to the
other medias.
These studies provide scientific evidence for the advantages of translucent pots, and also indicate that chunky peat can be used as an alternative to a bark-based media.

Sorry, I don't know how the smilies got in there

[Dorothy]

So what this is saying is it's best to pot your phals (doritis or dtps) in translucent pots
and the better medium for those growing conditions are either
chunky peat: perlite mix (1:1 ratio)
or
chunky peat:charcoal mix (what is the ratio for this?)


About smilies -
You needed to put a space between the : and p otherwise you get this >>

[Ray]

I have to wonder about their conclusions.

If you read the "Results and Discussion" of that paper, it starts by stating that there was no growth difference in the vegetative part of the plants between the pots.

If we are to believe the conclusion that translucent pots are better than opaque because the plant doesn't need to grow aerial roots through which to photosynthesize, we might have expected more of the energy to go into plant growth....but it apparently didn't.

[Sun rm.N.E.]

Ray

Thanks for your reply.
i was wondering if you have any observations on this based on your experience?
I have seen comments about whether orchid roots of various species grow better exposed to light or not but have not found much research.

[Ross]

My experience seems to duplicate this (after all, MSU is not far from me). When I grow Phals (or other orchids whose roots are known to photosynthesize) in clear/milky pots, they grow gangbusters and with no surface roots. When I grow Phals (and others) in solid colored pots, there are surface roots. Not conclusive, but certainly worthy, of further study.

[Sun rm.N.E.]

Ross

Thanks. After many years of not growing them I got 2 new Phals. and I would rather have their roots in the pot instead of in the air where they will probably not like my low humidity in the winter.

[Ross]

Originally Posted by Sun rm.N.E.

Ross

Thanks. After many years of not growing them I got 2 new Phals. and I would rather have their roots in the pot instead of in the air where they will probably not like my low humidity in the winter.

If you are in North east, then you heat with fossil fuels so humidity is less in winter than, perhaps, in summer. If this is the case, 'clear' pots offer the ability to monitor the amount of moisture in the medium prior to watering. I rely on this for mine, including Paphs and other species.

[Grandma M]

I went to the article "Orchid Grower" 4th section. It had a bit of useful information for phal growers on cooling. (Table 1 and 2)
Marilyn

[Sun rm.N.E.]

Thanks Ross. I find your experience very helpful in this and other posts. A little tweaking here and there can make a difference when conditions are less than optimal.

[Sun rm.N.E.]

Marylin

You picked up on some useful information.
I also thought they had good pictures on cold injury in Phals in the article: Growing the Best Phal.