Root growth of Taxodium mucronatum Ten. planted in an urban area

Introduction: The ahuehuete (Taxodium mucronatum Ten.), National Tree of Mexico, is frequently found in urban green areas, in conditions of restricted humidity and compacted soils. These characteristics negatively affect growth and survival. Objective: To evaluate root growth of young ahuehuete trees by the effect of the frequency of irrigation and loosening of the soil surrounding the planting strain. Materials and methods: 24 trees 2 m high were planted in an urban area. The experiment was established as a completely random design with factorial arrangement: a) irrigation frequency (frequent [once weekly] and spaced [once every two weeks]) and b) treatment of the soil surrounding the plantation strain (soil with and without loosening). The growth of the root system was monitored for 12 months through digital photographs, obtained from rhizotrons installed on a side wall of each plantation strain. Results and discussion: The original compaction of the site did not present restrictive levels for growth; therefore, the surrounding loosening did not significantly improve (P > 0.1) short-term root growth. Root length (267.75 to 453.28 cm) showed no statistically significant differences for the irrigation and soil factors and their interaction; however, the number of roots was affected by the interaction of the factors (P ≤ 0.1). Trees with frequent irrigation and soil without loosening developed a higher number of roots (190.5). Conclusion: The interaction of irrigation frequency and soil condition influences the number of roots, but not the length.