William C. Fonteno

Advancements in Root Growth Measurement Technologies and Observation Capabilities for Container-Grown Plants

The study, characterization, observation, and quantification of plant root growth and root systems (Rhizometrics) has been and remains an important area of research in all disciplines of plant science. In the horticultural industry, a large portion of the crops grown annually are grown in pot culture. Root growth is a critical component in overall plant performance during production in containers, and therefore it is important to understand the factors that influence and/or possible enhance it. Quantifying root growth has varied over the last several decades with each method of quantification changing in its reliability of measurement and variation among the results. Methods such as root drawings, pin boards, rhizotrons, and minirhizotrons initiated the aptitude to measure roots with field crops, and have been expanded to container-grown plants. However, many of the published research methods are monotonous and time-consuming. More recently, computer programs have increased in use as technology advances and measuring characteristics of root growth becomes easier. These programs are instrumental in analyzing various root growth characteristics, from root diameter and length of individual roots to branching angle and topological depth of the root architecture. This review delves into the expanding technologies involved with expertly measuring root growth of plants in containers, and the advantages and disadvantages that remain.

Physical analysis of rockwool slabs and effects of fiber orientation, irrigation frequency and propagation technique on chrysanthemum production 1

Abstract Chrysanthemum X morifolium ’Bright Yellow May Shoesmith’ was grown as a cut flower crop in rockwool slabs in various methods to test different cultural and rockwool options. Direct planting of unrooted and calloused cuttings led to deleterious water stresses in spite of a commercially prohibitive input of labor for syringing. Planting of partially rooted cuttings was successful in terms of flower production but required excessive labor. Satisfactory and equal results were obtained from 1) inserting cuttings rooted in rockwool cubes into the slab such that the cube top was either flush or 1.3 cm above the slab surface, 2) applying nutrients 1 or 3 times per day, and 3) a horizontal or verticle fiber orientation in the slab. Nutrient accumulation in plants of all treatments were in satisfactory ranges and did not account for observed differences in growth.