Artificial pollination on hazelnut in South Africa: Preliminary data and perspectives

Hazelnut cultivation is rapidly expanding in regions outside its native range. New hazelnut plantations in South Africa are facing adverse environmental conditions which threaten the pollination process and hamper nut yield. Artificial pollination can increase fruit yield and fill pollination gaps in some fruit crops, but its application on hazelnut is still not well explored. This study investigated biological factors and technical procedures in the first artificial pollination experiment on hazelnut in South Africa. A suspension media for artificial application composed of 10% sucrose, 0,1% agar and 0,02% boric acid was used. In addition, alternative low-cost suspension media containing other forms of sugar were also evaluated. Moreover, a novel and practical approach to assess pollen conditions in liquid solutions was designed. Pollen viability was tested in the different suspension media. This varied greatly among the examined cultivars. Wild hazelnut produced pollen with the highest viability, while ‘Tonda Gentile delle Langhe’ (TGL) and ‘Barcelona’ the lowest. Sterile grains were very abundant, especially in cultivated varieties (up to 65% in TGL). Preliminary data on nut yield were also collected. Altogether, this study indicated that artificial pollination is a promising approach for hazelnut cultivation in increasing the final yield. Further research is needed to develop integrated pollination strategies, especially in areas where the environmental conditions are adverse to the pollination process.