Fresh market demands high quality fruit and, therefore, citrus growers and researchers are constantly looking for solutions to avoid seed presence. Current horticultural techniques have low effectiveness or high cost. The objective of this study is to evaluate the inhibition effect of seven products on the in vivo pollen tube growth in Nadorcott mandarin, which is a high-value seedy variety. To achieve this main objective, three inorganic fertilizers (ammonium nitrate, potassium nitrate, sulfur), and four saccharides (saccharose, methyl cellulose, callose, chitosan) were applied to Nadorcott stigmas 24 h before and after hand pollination. Pollen tubes were counted 1, 3, and 5 days after treatment in longitudinal blue violet autofluorescence-stained sections. Of the seven evaluated products, only sulfur had a strong inhibitory effect. Elemental sulfur (S₈) inhibited pollen tube growth by 94-100%. This strong effect was observed regardless of sulfur being applied 24 h before or after pollination, and on fixed flowers 1, 3 or 5 days after applications. Saccharose treatment seemed to have the opposite effect: stimulated pollen tube growth, but the difference with the positive control was small and non-significant. The sulfur effect could be useful for designing agronomic applications capable of preventing seed presence in Nadorcott mandarin.

新鲜市场需要高质量的水果，因此柑橘种植者和研究人员一直在寻找避免种子存在的解决方案。当前的园艺技术效率低或成本高。本研究的目的是评估七种产品对体内Nadorcott柑橘花粉管生长，这是一种高价值的种子品种。为了实现这一主要目标，在人工授粉前后 24 小时，将三种无机肥料（硝酸铵、硝酸钾、硫磺）和四种糖类（蔗糖、甲基纤维素、胼胝质、壳聚糖）施用于 Nadorcott 柱头。处理后 1、3 和 5 天，在纵向蓝紫色自发荧光染色切片中对花粉管进行计数。在七种评价产品中，只有硫具有很强的抑制作用。元素硫 (S ₈) 抑制了 94-100% 的花粉管生长。无论是在授粉前或授粉后 24 小时施用硫磺，还是在施用后 1、3 或 5 天对固定花施用硫磺，都观察到这种强烈效果。蔗糖处理似乎具有相反的效果：刺激花粉管生长，但与阳性对照的差异很小且不显着。硫效应可用于设计能够防止 Nadorcott 柑橘种子存在的农艺应用。