Optimization of Offshoot Outgrowth in Globe Artichoke Using a Combination of Chemical and Mechanical Treatments

Abstract

The application of cytokinins is a good tool to promote axillary buds in many species, but plant decapitation or leaf cut-back are also suitable methods. This research aims to establish a strategy for artichoke cutting production using a combination of chemical and mechanical treatments. Two experiments were conducted in Tunisia to investigate the effect of 6-benzylamino purine (BAP) on shoot outgrowth in globe artichoke combined with the leaf cut-back at collar level one week after BAP treatment. The first trial was tested in a spring offshoot nursery and the second one in a field of micro-propagated mother plants grown for two years. Five treatments were tested in both experiments: BAP 0 ppm + no cut-back (T1), BAP 0, 100, 200, and 300 ppm + cut-back (T2, T3, T4, and T5 respectively). Regarding growth aspects, the highest number of offshoots was obtained in T4 for both trials with an increase of 49.2% and 37.8% compared to T2 nursery and field values, respectively. T4 also showed a faster rhythm of shoot emission and the biggest shoot size compared to the other treatments. Significant interactions between BAP treatments and offshoot size were recorded for morphological and weight parameters. Regarding the offshoot mineral composition, relevant differences were observed among BAP treatments; moreover, the higher BAP concentrations induced a significant decrease of NaCl plant uptake. Therefore, the combination of BAP 200 ppm and the leaf cut-back could be a potential method to enlarge the cutting production of globe artichoke also reducing some stressful conditions.