Grass pollination in different cities of Argentina and Paraguay in 2018: a comparative study

The Poaceae constitutes a large family distributed elsewhere. This family is one of the best represented in South America, with 206 genders that includes 1523 species distributed in 10 different subfamilies. A comparison between pollination was made in 2018 in the following cities: Asunción (Paraguay), Latitude S 23°0'0", Córdoba (Argentina), S 31°24'48.6", Santa Rosa, La Pampa (Argentina), S 36°37'0.01", Bahía Blanca (Argentina) S 38°47'10.72” and Bariloche (Argentina) S 41°9'0". The goal of this study is to compare the length and peak of pollination of Poaceae in various cities in Argentina and Paraguay located in different latitudes. For pollen counts, a type Hirst suction pollen counter was used in Paraguay. In Argentina, an impact counter type Rotorod 40 was used. The counts were done daily and expressed in grains/ m3 of air. Five or more grains within 5 following days was defined as the start of the pollination period and end of the period determined when less than 5 grains for more than 5 days were determined. Poaceae pollination in Argentinean cities was determined between October and March. On the other hand, in Asuncion, Paraguay, two well differentiated periods were shown in September and February. Pollination started at different moments according to the city Latitude. This study shows that Poaceae pollination goes from last spring to fall. There is a significant difference in pollen counts between Asuncion, Paraguay and the cities studies in Argentina. This might be attributed to the different climate conditions between them, including temperature and humidity.