Orientation Affects Growth and Harvest Yield of Ocimum basilicum ‘Cardinal’ L. Grown on a Novel, Inexpensive Vertical Structure

Abstract

Cardinal basil (Ocimum basilicum ‘Cardinal’ L.) was grown on a novel, inexpensive, A-frame vertical structure developed at Auburn University. The structures were built from treated lumber with cattle fencing on each of the two panel faces. One cattle fencing panel held 15, square pots [15.2 cm (6.5 in) wide × 16.5 cm (6 in) tall] with one plant per pot. One structure with two vertical panels facing opposite directions occupied 1.5 m2 (16 ft2) of horizontal greenhouse space, as did the traditional, horizontal greenhouse bench treatment used for comparison in this work. The objective of this research was to compare how structure orientation and season affected growth and biomass harvested for basil grown on vertical structures compared to a bench. The treatments were a north-south (N-S) oriented vertical structure, an east-west (E-W) oriented vertical structure, and a bench (control). All pots received drip irrigation. Basil plants were harvested to three remaining nodes per plant every 4 weeks for a total of two harvests per seasonal experiment, to mimic typical foliar harvests. Leaf number (LN), leaf fresh weight (LFW), and leaf dry weight (LDW) were recorded at each harvest. The two panel vertical structures produced the greatest LFW and LDW of basil on a greenhouse square foot basis. Regardless of orientation or season, both the N-S and E-W vertical structures produced a similar biomass of basil. The south orientation panel (0.75 m2 (8 ft2) horizontally) produced similar LFW, LDW, and LN compared to the bench [1.5 m2 (16 ft2)]. The east and west orientations produced similarly to the south orientation. The north orientation consistently produced the smallest basil biomass. The E-W oriented structure is recommended based on similar biomass produced and the implementation of similar cultural practices.