Pine litter as substrate for propagation of vegetable transplants in trays

The study evaluates the potential of pine litter for use as a substrate in the propagation of vegetable transplants in trays. Sub-optimum pH and electrical conductivity of pine litter were addressed by incorporating 10% feedlot manure by volume. The water holding capacities of pine litter and the pine litter-feedlot manure mixture were higher than the minimum required, but their air filled porosities were below optimum. The pine litter-feedlot manure mixture reduced the germination percentages of cabbage seedlings by 17% and lettuce seedlings by 13% relative to composted pine bark, but the germination percentage of tomato seedlings was similar in both substrates. There were no significant differences in the growth of vegetable transplants between the two substrates. In both substrates increasing nutrient availability by adding controlled-release fertilizer had similar positive effects on the growth transplants. Substrate-nutrient availability interactions were only observed in dry shoot mass of lettuce seedlings and dry root mass of tomato seedlings. Composting the pine-litter animal manure mixture could possibly improve the observed low germination percentage of vegetable transplants in pine litter.