Improved Medium for Organic Transplants E4
Ministry of Agriculture, Agricultural Research Organization, Division of Organic Agriculture, Newe Ya'ar Research Centre, P. 0. B. 90000 Haifa, 31900 Israel
|Transplants for organic vegetable production are
commonly produced in Israel in »speedling« trays. The commercial growth medium consists
of mixtures of peat moss and vermiculite. The young plants frequently exhibit non-uniform
quality. Growers experience unacceptable mortality rates both just after transplanting and
during later stages, due to susceptibility to soil-borne diseases and to low root to shoot
Substituting part of the peat moss with compost, based on the coarse fraction of separated cattle manure, caused a significant improvement of the seedlings in the nursery. Improved parameters included growth rate, chlorophyll content and root to shoot ratio. This resulted from increased availability of nutritional elements and from the effect of rooting promoters, occurring in the compost.
Once planted in the field, transplants of lettuce, cabbage and processing tomatoes exhibited lower mortality rates due to dumping-off diseases. When tested on the basis of survived plants only, plants grown from compost-containing media yielded higher yields as compared to the commercial controls.