Decreasing the concentration of IBA or combination with ethylene inhibitors improve bud retention in semi-hardwood cuttings of hazelnut cultivar ‘Tonda Gentile delle Langhe’

The effect of two concentrations (500 and 1000 mg L−1) of indole-3-butyric acid (IBA) and the combination of IBA treatments (1000 mg L−1) with two ethylene inhibitors, 1-MCP (1-Methylcyclopropene) and AgNO3, on adventitious root formation and bud retention of semi-hardwood cuttings were investigated in hazelnut (Corylus avellana L.) cultivar ‘Tonda Gentile delle Langhe’.The IBA 500 mg L−1 treatment promoted percentages of rooting (70.0%) similar to IBA 1000 mg L−1 treatment but reduced bud abscission resulting in 56.3% of rooted cuttings with at least one bud retained. The use of 1-MCP and AgNO3 in combination with IBA 1000 mg L−1 treatment reduced bud abscission without modifying the rooting response.

► Buds abscission is a limiting factor to propagation of hazelnut stem cuttings. ► The effects of IBA and inhibitors of ethylene on root formation and bud retention of semi-hardwood cuttings were investigated in hazelnut. ► The application of exogenous auxin promoted rooting in hazelnut cuttings but affected bud retention. ► In ‘Tonda Gentile delle Langhe’ the use of IBA 500 mg L−1 promoted rooting and reduced bud abscission in comparison with higher IBA concentrations. ► The use of 1-MCP and AgNO3, in combination with IBA 1000 mg L−1 reduced IBA-induced bud abscission without modifying the rooting aptitude.