Productive response of two seed propagated artichoke cultivars to gibberellic acid, chlormequat and paclobutrazol applications.

Abstract

Plants of ‘Imperial Star’ and ‘Prelude’, planted on 30th July 2002, were sprayed three times, every two weeks, with gibberellic acid (GA3), chlormequat (CCC) and paclobutrazol (PBZ) at 30, 795 and 300 mg L-1respectively, starting on 13th September, applying a total of 375 L ha-1. Untreated plants served as controls. At the end of December 2002, plants of ‘Imperial Star’ had produced with all treatments, particularly with GA3, but ‘Prelude’ plants had only produced when treated with GA3. By the end of February 2003, plants of both cultivars treated with GA3 yielded the same, similar to ‘Imperial Star’ plants treated with CCC. With the exception of GA3-treated plants, ‘Imperial Star’ produced significantly higher yields than ‘Prelude’. By the end of the experiment (end of May 2003) ‘Imperial Star’ plants also yielded more than ‘Prelude’ while GA3-treated plants of ‘Imperial Star’ produced significantly less than those of other treatments included controls. With all treatments, ‘Prelude’ gave similar yields. Average head weight was slightly higher in ‘Imperial Star’ than in ‘Prelude’, and it was similar among treatments except in plants treated with GA3. In this case, the GA3-treated plants yielded a lower head weight at the end of February and May 2003. Unmarketable production was higher in the cultivar ‘Imperial Star’ and slightly higher, albeit not significantly, in GA3-treated plants.