USE OF ALTERNATIVE SUBSTRATES FOR BROCCOLI SEEDLING PRODUCTION UNDER GREENHOUSE CONDITIONS

Abstract

In this study, the effect of two alternative growing substrates (corncob and Azolla anabaena) on some vegetative parameters (days to emergence, stem diameter, plant height and root volume) in seedlings of broccoli hybrid Coronado were evaluated. Both materials were ground and used according to the following treatments: 100% corncob (T1), 100% Azolla (T2), 50% corncob + Azolla 50% (T3), corncob 75% + Azolla 25% (T4), 25% corncob + Azolla 75% (T5) and then compared to a commercial substrate (BM2) (T6). Substrates were uniformly mixed, deposited in germination trays and watered at field capacity. Additionally, physic-chemical characteristics were determined in the different substrates used for broccoli seedling production. Stem diameter, height plant and root volume showed to be statistically higher in seedlings grown in commercial substrate (0.18 cm, 5.27 cm and 0.61 cm3, respectively) followed by those seedlings grown in 100% Azolla (0.17 cm, 4.92 cm and 0.49 cm3, respectively) (p< 0.001). Seedlings growing in substrates with higher corncob proportion showed lower values in these vegetative parameters. Based on our results, Azolla showed potential to be used as a seed substrate for production of broccoli seedlings, thus decreasing the use of peat and consequently the production costs in nurseries.