Tung husk and carbonized rice husk
mixes as substrates for Dendranthema
morifolium Tzevelev ‘golden polaris’
rooting under plastic coverage.
The Chinese tung tree (Aleurites fordii Hemsl)
is cultivated on small farms in the State of Rio Grande
do Sul, Brazil, for the tung oil industry. Tung oil,
also known as wood oil, is used mainly as an ingredient
for paints and varnishes. Tung husk (CT) are a
by-products of this industrial process. The high content
of long-lasting fibers suggests that CT could be
appropriate to be mixed in substrates for potted
plants. CT shows high water retention in micropores
and, to correct this characteristic, should be mixed
to materials with good drainage. The present study
was conducted to evaluate CT and carbonized rice
husk (CAC) mixes as substrates for chrysanthemum
rooting under plastic coverage. Five blends were
evaluated: 1CT, 3CT:1CAC, 1CT:1CAC, 1CT:3CAC
and 1CAC, plus CACV (CAC: superfine vermiculite
6:1 v:v) as a reference material. To characterize
these mixes, salinity, pH, bulk density and water retention
curves were measured. Both CAC and CACV
showed similar efficiency as a rooting media, with
excellent results for this species. Chrysanthemums
rooted in the presence of CT showed a different morphological
development, with more numerous and
darker roots but shorter in length, indicating the presence
of composts that interfered on the rizogenesis.
These differences cannot be considered as negative.
Within the blends containing tung husks, 1CT:3CAC,
followed by 1CT showed the best results. This was
related to their higher easy available water content.