The effect of peat replacement in horticulture media by willow ( L.) biomass compost for cucumber transplant production.

This research evaluated the usefulness of horticultural substrates prepared on the basis of compost from chipped willow without additives and with the addition of nitrogen and decomposing mycelium of the cellulose-lignin fraction of wood in the cultivation of cucumber seedlings. The produced composts were mixed in different proportions: mixture 1 (W1) - the proportion of compost without additives and compost prepared with the addition of nitrogen and mycelium was in the ratio of 50:50, mixture 2 (W2) - the proportion of compost without additives and compost prepared with the addition of nitrogen and mycelium was in the ratio of 75:25. The starting mixtures were used to prepare horticultural substrates with different components (peat - P, vermicompost - V) and additives: basaltmeal - B, biochar from deciduous wood - C. The components were added in varying proportions. A total of 29 different substrates were subsequently tested in the study. Plant showed that the traits assessed varied to a greater extent under the effect of the test factors than at earlier growth stages. It was demonstrated that cucumber grown on substrates with 75% or 50% willow compost had a unit weight at the same statistical level as when grown on peat substrate (P). The plants with the highest unit weight (8.5- 10.4 g), belonged to the same homogeneous group and derived from sites W1P1B2, W2P1, W1P1B1, W2P2, W1P1C1, P, W1P1, W2B1, W2P2B2. High-quality cucumber transplant should characterise well develop, optimal height-to-stem thickness ratio, short hypocotyl, thick green leaves and cotyledons.