BENEFICIAL EFFECT OF COCONUT FIBER AND PEAT ON THE PHYSICAL QUALITY OF NURSERY SUBSTRATES

During the production of nursery plants in summer, when the plants are well developed, the water requirements can be very high, requiring very frequent watering. The main challenge in developing high-performance substrates offering more available water is usually the establishment of optimal amounts of air and water in the substrate. The purpose of this study was to evaluate the impact of coconut fiber and peat on the physical quality of nursery substrates. The performance of five organic substrates for Rudbeckia Goldsturm production was evaluated by adding different proportions of coconut fiber and peat. The substrate composed of bark and 10% additional peat moss resulted in a 12% increase in easily available water (EAW) compared to other substrates. EAW improvement did not affect the number of waterings; however, it had a beneficial impact on the growth and development of Rudbeckia. The associated parameters were growth index (11%), shoot dry weight (17%) and root dry weight (8%). Inversely, increasing rate of applying coconut fiber up to 30% brought about a 47% improvement in relative gas diffusivity compared to the control with no important impact on EAW.