Measurement and analyses of growth and stress parameters of Viburnum odoratissimum (Ker-gawl) grown in a multi-pot box system

Abstract

Two colors (white and black) of a recently introduced irrigation-plant production system [multi-pot box system (MPBS)] for container-grown nurseries were researched and results were compared with those obtained from the sprinkler-irrigated conventional (control) system (CS). Experiments were carried out in summer and fall of 2001 in Gainesville, Fla. Plant growth [growth index (GI), growth rate (GR), and dry matter] and stress parameters [stomatal resistance (rs), crop water stress index (CWSI), plant water potential (PWP), and substrate temperature (ST)] were measured and analyzed for Viburnum odoratissimum (Ker-gawl). In both seasons, plants grown in the white MPBS had significantly higher GI and GR as compared to the plants in the black MPBS and CS. In summer, plants in the white MPBS reached marketable size about 17 days and 86 days earlier than those in the black MPBS and CS, respectively. In fall, they reached marketable size about 25 and 115 days earlier than those plants in the black MPBS and CS, respectively. Plants in the white and black MPBSs showed exponential growth rate in summer with plants in the white MPBS having significantly higher growth rate (greater slope) than the other two treatments. In both seasons, plants in the white MPBS produced the highest amount of dry matter. In general, plants in the white MPBS had lower r s values to vapor transport compared to the other two treatments, and the black MPBS treatment had lower rs values than the CS in both seasons. The CWSI values of the plants in both white and black MPBSs were significantly lower than the CS. In both seasons, ST in the black MPBS and CS exceeded the critical value of 40°C several times. The ST of >40°C is often reported to significantly reduce the plant growth and cause root death and/or injury for container-grown plants. Overall, the white MPBS provided a better environment for root development and plant growth under these experimental conditions. Results strongly suggest that there is a potential opportunity of using MPBS for irrigation and production of nursery plants. These important findings suggest that, in practice, producing nursery plants in a shorter period of time by using white MPBS will result in significant savings of energy, water, chemicals, and other inputs and thereby reducing the costs and increasing profits.