PRELIMINARY RESULTS OF SUPPLEMENTARY POLLINATION ON HAZELNUT IN SOUTH CHILE

Hazelnuts (Corylus avellana L.) are wind pollinated crops, monoecious, mostly dichogamus and self-incompatible, as an exception some cultivars are partially self-compatible. For this reason, hazelnuts trees require compatible and good pollinizer cultivars (2-3) with large amounts of catkins which produce abundant and viable pollen and shed its pollen on different pollen shedding dates and at the peak of female flowering to obtain sufficient yield. The flowering of the pistilate flowers occurs in winter in June through July in the ‘Chilean Barcelona’ cultivar in Araucania, southern Chile and its stigmatic surface remains receptive for up to about 3 months. However, the overlap of pollen and stigma receptivity can change from year to year and depending principally per climate conditions and some pollinizers produce a high percentage of non-viable pollen. On the other hand, hazelnut pollination can fail in winter by weather conditions because pollen grain is not well captured by the stigma surface due mainly to excess of rainfall, high environmental humidity, low temperatures, and absence of wind during the pollination process. The aim of this study was to determine if supplementary or artificial pollination can increase yield of nuts. In field experiments in hazelnut orchards in Araucanía region, we found that treated trees of seven-year-old ‘Chilean Barcelona’ cultivar produce a 37.3% higher yield than those which only received drifting pollen from nearby pollinizer cultivars. Preliminary results showed that supplementary or artificial pollination can significantly improve yield in hazelnut, mainly with adverse climate conditions as excess of rain, high humidity and cold during the pollen shed and receptivity of stigmatic surface. We conclude that supplementary pollination of hazelnut could improve natural wind pollination and may result not only in higher crops, but also in better quality of nuts.