Pollen Concentration Data of Xanthium spp. Between 2014 and 2019 in Hungary

The species of Xanthium italicum and X. spinosum belong to the same subgenus group as ragweed (Ambrosiinae), they are both invasive, allergenic weeds. Pollen concentrations of Xanthium spp. Were analyzed in air samples collected with a 7-day Hirst-type (Burkard) pollen trap placed in the Northern Great Plain region (Jász-Nagykun-Szolnok county, Hajdú-Bihar county, Szabolcs-Szatmár-Bereg county) during the 6-year period 2014–2019 at the three county capitals (Szolnok, Debrecen, Nyíregyháza), in Hungary. The pollen season was defined as the day on which the sum of the daily average pollen concentration reaches 1% of the total amount, and the end of the season was defined when it reaches 99%. The highest annual total pollen count was detected in 2018 in Jász-Nagykun-Szolnok county (116 pollen), and the lowest in 2018 in Szabolcs-Szatmár-Bereg county (12). The highest amount of pollen grains was counted on August 24th (16 pollen/m3) in Debrecen, in 2015. The lowest daily value was recorded on August 25th (4 pollen/m3) in Nyíregyháza, in 2019. The results show that Xanthium spp. Species have relatively low pollen concentrations, which is striking compared to the closely related common ragweed: the highest daily pollen count of A. artemisiifolia in the same region (658) is more than 40 times that of Xanthium spp.; while the 6-year average of its total pollen count (12,863) is almost 263 times higher. Among the possible explanations, pollen production and the number of individuals are important. Pollen monitoring provides information on the size of Xanthium spp. Stands.