EVALUATION OF ALTERNATIVE POTTING MEDIA IN DIEFFENBACHIA AMOENA AND EUPHORBIA PULCHERRIMA

In 1986 25 different substrates have been tested on Dieffenbachia amoena cv. "Tropic Snow" and Euphorbia pulcherrima cv. "Diamond".

The main purpose of this work, which will continue in future, is to standardize substrates composition for potted plants, looking for possible alternatives to traditional ones (peat, leaf mould, sand).

Nine mould components were mixed together at different ratios: sphagnum peat moss, uncomposted bark, composted bark, argex, perlite, polystyrene, leaf mould, sand and hydrogel.

During the cultivation test, analyses to determine water release curve, according to the method experienced by De Boodt et al. (1974), have taken place.

Observations of plants have revealed that a ratio of 30 % peat is sufficient to assure a good water retention.

Best draining components were perlite and argex, used at a percentages not higher than 20 %, in respect of polystyrene and sand.

The uncomposted bark, because its higher C/N ratio, brought to stunted plants and very evident yellowings.

At the opposite, the composted bark, having a water retention worse than peat, gave excellent results, in particular on Dieffenbachia.

Symposium on Horticultural Substrates and their Analysis

G. D’Angelo, P. Titone

https://doi.org/10.17660/ActaHortic.1988.221.16