Summary
Pollen concentrations were low at all sites except Potchefstroom where the weed concentration increased. The dominant weed was ragweed. Moulds were significant in Durban. An interesting tree pollen found in Durban, Bloemfontein and Gqeberha in low concentrations was marula.
Cape Town
4-year means are given but the Cape Town spore trap is now running and counts will be available from next week. Pollen and mould concentrations are low in this autumn period and tree pollen typically detected is Australian pine (Morella), forest elder (Nuxia), elm (Ulmaceae), ash (Fraxinus) and gum (Myrtaceae). Weeds are the daisy family (Asteraceae) and ferns (Polypodiaceae). Moulds are low.
Johannesburg: 4-year means are given. Pollen and mould concentrations are usually low at this time of year. Trees are cypress (Cupressaceae), bushwillow (Combretaceae), mulberry (Moraceae), gum (Myrtaceae), pine (Pinaceae) and poplar (Populaceae). Weeds are the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae), the daisy family (Asteraceae), mallows (Malvaceae), slangbos (Stoebe-type), ferns (Polypodiaceae), heather (Ericaceae) and spurges (Euphorbiaceae). Moulds are low.
Pretoria
Extremely low pollen concentrations were found during this sampling week. Trees were birch (Betulus), forest elder (Nuxia) and elm (Ulmaceae). No weeds were detected and moulds were low with some significant spikes for the allergenic mould Cladosporium.
Bloemfontein
Pollen concentrations in all three categories were low. Trees detected included the sumac family (Anacardiaceae), lindens (Tiliaceae), marula (Sclerocarya), ash (Fraxinus) and poplar (Populaceae). Weeds were pigmyweeds (Crassulaceae), iris (Iridaceae), mint) Lamiaceae) and erica (Ericaceae). moulds were low.
Kimberley
Tree, grass and weed pollen concentrations were low. Trees detected included waxberry (Morella), bushwillow (Combretaceae) and elm (Ulmaceae). Weeds were bulrush (Typhaceae) and mugwort (Artemisia). Moulds were low with small spikes for the allergenic mould Cladosporium.
Durban
Tree, grass and weed pollen concentrations were low as rain removed pollen grains from the air. Trees included bushwillow (Combretaceae), marula (Sclerocarya), poplar (Populaceae), birch (Betulaceae) and gum (Myrtcaeae). Weeds were ragweed (Ambrosia), knotweed (Persicaria), the carnation family (Caryophyllaceae) and the daisy family (Asteraceae), Moulds were moderate with strong spikes for ascospore following rain.
Gqeberha
No grass was detected at this site. Low tree concentrations included Australian pine (Casuarina) and marula (Sclerocarya). No weed pollen was seen and moulds were low.
Potchefstroom
Tree and grass pollen was low, but moderate weed concentrations were seen. Trees identified included bushwillow (Combretaceae), pine (Pinaceae) and karee (Rhus/Searsia). Weeds were ragweed (Ambrosia), the dominant weed, mugwort (Artemisia) and the daisy family (Asteraceae). Moulds were low.
George
Few pollen grains were detected during this wet and rainy sampling week. Trees included alder (Alnus), waxberry (Morella) and forest elder (Nuxia) and mulberry (Moraceae). Weeds were ferns (Polypodiaceae), buttercup (Ranunculaceae) and goosefoot (Chenopodiaceae). Moulds were low but increases in ascospores are noted after rain.
Reference Range
Grass: Low: 0-5 Moderate: 6-20 High: 21-200
Trees: Low: 0-15 Moderate: 16-90 High: 91-1500
Weeds: Low: 0-10 Moderate: 10-50 High: 51-500
Moulds: Low: 0-900 Moderate: 900-2500 High 2500-25000
Unit: per cubic metre
