The aim of this study was to determine morphometric differences of fruits and seeds between 19 selected American persimmon (Diospyros virginiana L.) genotypes. The genotypes of American persimmon have been growing more than 15 years in Forest-Steppe of Ukraine in the M.M. Gryshko National Botanical Garden of NAS of Ukraine. They are well adapted to the climatic and soil conditions. The fruits were collected at the period of their full maturity (October).

<p>The control of plant pollen season patterns is especially important in the expectation of climate change, as the timing of potential varying pollen seasons affects the human population. An ever-increasing number of people suffer from hay fever symptoms with varying severity during the pollen season. This paper presents data on the seasonal variations of pollen concentration and the factors which are the likely causes of these variations in Vinnytsya, a city in Central Ukraine, in order to establish the apparent pattern of this variation and so improve the efficiency of hay fever control in Ukraine.</p><p>Pollen counts were obtained by gravimetric and volumetric methods employing a Hirst-type volumetric spore trap.</p><p>Alder (<em>Alnus</em>) and birch (<em>Betula</em>) peaks of pollen release occurred approximately 1 month earlier than was observed at the end of the twentieth century. This was due to the seasonal heat accumulation related to the appropriate temperature regimen registered in January and February prior to the growing season. Other trees – including poplar (<em>Populus</em>), maple (<em>Acer</em>), walnut (<em>Juglans</em>), common hazel (<em>Corylus</em>) – did not show distinct changes in pollen season pattern over the past decades.</p><p>Mean daily temperature seems to be the leading factor promoting early season onset and a seasonal pollen peak shift of the grass and herb flora such as ragweed (<em>Ambrosia</em>). The shift of the ragweed seasonal pollen maximum towards later in the season correlated with higher temperatures during September. Our study has shown that droughts may also significantly decrease the ragweed pollen concentration.</p>

The paper provides a simulation of the occurrence of <em>Ambrosia</em> pollen in Ukraine both in terms of a determination of the regions with high pollen concentrations and the time when the high pollen load occurs. Simulation was performed using the SILAM system and the following pollen mapping using the Grid Analysis and Display System. Simulation results were compared with the aerobiological data available from six monitoring stations in Ukraine. A decrease in the concentrations of <em>Ambrosia</em> pollen, the duration of the <em>Ambrosia</em> season, and patient exposure to the <em>Ambrosia</em> pollen were apparent from SE to NW of Ukraine. A close correlation between the modeled and actually registered pollen concentration values and ragweed pollen release periods was observed in all the cities for which the <em>Ambrosia</em> pollen monitoring data had been collected. Further investigations are required to provide accurate forecasts for other types of airborne allergens.

No abstract

No abstract