GROWTH REGULATORS ON POLLEN GERMINATION IN OLIVE

The research aimed at evaluating the effects, in vitro and in vivo, of a biostimulant and some growth regulators on pollen set ability in the four main olive cultivars diffused in Tuscany (‘Frantoio’, ‘Moraiolo’, ‘Leccino’ and ‘Pendolino’). Germination and pollen tube development were studied using: boric acid at concentrations of 50 and 100 pm, gibberellic acid, GA₃ at 25 and 50 ppm, Paclobutrazol, PP333 at 100 ppm and the biostimulant Siapton 10L at 500 and 1 000 ppm. Germination proved satisfactory for all four cultivars, though appreciably slower than in other species. Siapton 10L had favourable effect only on in vivo pollen tube elongation.