Poinsettia (Euphorbia pulcherrima)cultvation in biodegradable pots: mechanical and agronomical behaviour of pots and plant traits.

Poinsettia is a typical example of winter ornamental pot-plant because of its strong demand concentrated in the Christmas period. In Italy about 20 million of Poinsettia plastic pots are produced per year becoming a waste at the end of their utilization. A solution of this environmental problem could be the use of biodegradable and compostable pots instead of traditional ones. Nevertheless, it is necessary to verify if these materials, although having biodegradability properties, are able to ensure comparative levels of technical use as traditional plastic materials. In this paper, three different kinds of biodegradable pots (biodegradable polyester, plain, or variously added with compostable materials) plus a traditional one (polypropylene, PP), used in a cultivation of Poinsettia (cv. Premium red), carried out in a heated greenhouse located in Southern Italy (40° 38’ 27’’ N; 14° 55’ 21’’ E; 50 m a.s.l.), were studied regarding over time mechanical behaviour of pots and agronomical response of plants. Results have showed that plain biodegradable polyesters pots have a good mechanical resistance and a fixed colour over time. On the contrary, pots made of biodegradable polyesters variously added of compostable materials don’t seem appropriate for Poinsettia cultivation. The study needs more observations to better fix the obtained results before communicating them to the interested growers.