Effect of different vermiculite and pine bark media substrates mixtures on physical properties and spiral rooting of radish (Raphanus sativus L.) in float tray system

Soilless culture in the form of float tray system involves the use of media substrates which are blended to provide nourishment to the grown crop. This method is associated with many advantages such as enabling good root growth and improved germination rates. The experiment was carried out under green house conditions to evaluate the implications of substrate physical properties. Vermiculite and pine bark were mixed at 100%, 75%, 50%, 25% and 0% by volume. Farmers standard practice (50% pine bark+sand 50%) was included as a control. ln the experiment the treatments were laid out using Random Complete Design and were replicated three times to make eighteen treatments altogether. Water holding capacity increased with decreasing the percentage proportion of vermiculite (super fine). However, there was a positive correlation between percentage proportion of vermiculite and total porosity, air capacity against percentage proportion of vermiculite there is a negative correlation. Also bulk density was negatively correlated to percentage proportion of vermiculite. Germination decreased with increasing vermiculite at 3-4 days after sowing. A mix of between 0 to 50% seemed ideal for germination. Media substrate properties such as bulk density, total porosity, water holding capacity and air porosity were collected and subjected to Analysis of Variance using Genstat at P<0.05. However, farmers are advised to adopt blending technique of media substrate and float tray system which is environmentally friendly to the ecosystem which also saves water and nutrient management.