Role of planting density on the growth efficiency of Juniperus virginiana L. under open-air hydroponic conditions of the Ararat Valley

Abstract

Juniperus virginiana (J. virginiana) is an evergreen coniferous tree, which has wide usage not only in green construction, but also in folk medicine as a source of valuable bioactive substances. The high demand for the tree forces the development of new methods for plant cultivation. Hydroponics is considered to be one of the most popular methods. As the soilless growing perspectiveness of J. virginiana in Armenia has previously been confirmed by our experiments, the optimization of growing conditions, which bests suits for the enhancement of the growth efficiency and accelerated production of viable trees remains an actual issue. Optimization of the planting density (PD) is one of them. Taking into account the abovementioned in the frame of this study the role of PD on the growth efficiency of J․ virginiana has been studied in open-air hydroponic conditions of the Ararat Valley for the first time. The saplings of the tree were planted in volcanic red slag with three different PDs: 10, 12 and 14 plants per square meter. According to the biometrical measurements, no significant differences between the variants were observed at the end of the experimental period. In October an average height and stem diameter of the plants grown in various PDs were fluctuated between 71.7–76.5 cm and 13.9–14.5 mm, accordingly. Positive relationship between the plant height and stem diameter of J․ virginiana during the whole vegetation period has been observed. Our preliminary studies showed, that all the applied PDs are preferable for early years of hydroponic growing of J․ virginiana in open-air hydroponic conditions of the Ararat Valley.