Effects of physical, mechanical and hormonal treatments of seed-tubers on bud dormancy and plant productivity

The aim of this study was to develop a technique easy to apply in order to induce seed-tuber dormancy breakage. Over a two-year study, more than seven dormancy-breaking treatments were tested through evaluating different temperature effects alone or combined with gibberellins application, cutting in half of seed-tubers, and early haulm killing. Three varieties per year were considered: Spunta and Monalisa (medium and long dormancy) in both years, Europa during the first year and Arinda during the second year (both characterized by a short dormancy period). We found firstly that Europa and Arinda promptly responded to thermal treatments, and secondly to the same thermal treatments in combination with the application of gibberellins. Although not easily applicable, especially when a large volume of seed-tubers has to be handled (seed-tuber producers), the cutting in half of the seed-tubers also had a satisfactory result. Notwithstanding that treatments did not perfectly overlap between the two experiments, results were qualitatively similar. Therefore, these findings allow us to conclude that treatment with post-harvest storage at 20 ◦C, followed by a treatment with gibberellic acid at 38 days from harvesting, is the most efficient in releasing dormancy, in ensuring a good vegetative growth and productive performance at field-level irrespective of the variety.