Agronomic treatments to avoid seed presence in ‘Nadorcott’ mandarin I. Effect on in vivo pollen tube growth

•Sulfur applied on Nadorcott mandarin stigma inhibited 94-100% pollen tube growth.•The effect of sulfur on the stigma was high 24 hours before and after pollination.•Sulfur strong effect can be useful to reduce seeds in mandarin.•Saccharose application on the mandarin stigma increased the number of pollen tubes.