Summary
Grass pollen is increasing in several summer rainfall regions. Tree pollen was moderate in Bloemfontein and spikes were seen for elm in Potchefstroom. In Durban, ragweed is appearing and moulds are high.
Cape Town
Pollen in the atmosphere was sparse in all three categories. Trees included acacia (Acacia-type), gum (Myrtaceae) and waxberry (Morella). Weeds were the daisy family (Asteraceae) and goosefoot (Chenopodiaceae). Moulds were very low. The strong SE wind is dispersing bioaerosols quickly but on calm days with a little moisture, small spikes were seen for some mould genera.
Johannesburg
This site is not operational. The figures given are means of the same time period for the previous four years. Tree pollen seen at this time include yellowwood (Podocarpaceae) and elm (Ulmaceae). Weeds are the carnation family (Caryophyllaceae), plantain (Plantaginaceae), mallows (Malvaceae) and goosefoot (Chenopdiaceae). Moulds would be low.
Pretoria
Pollen was low in the categories: Trees, grasses and weeds. Tree pollen included acacia (Acacia-type), palm (Arecaceae) and elm (Oleaceae). Weeds were goosefoot (Chenopodiaceae), nettles (Urticaceae), knotweed (Persicaria) and plantain (Plantaginacea). Moulds were low, with small spikes appearing for Cladosporium, the allergenic fungal spore/mould.
Bloemfontein
Pollen increased to significant concentrations in all three categories during this sampling week. Trees identified were acacia (Acacia-type), birch (Betulaceae), olive (Oleaceae), African stinkwood (Celtis Africana), bushwillow (Combretaceae), mulberry (Moraceae), poplar (Populaceae), karee (Rhus/Searsia), olive (Oleaceae) and elm (Ulmaceae). Dominant trees were mulberry, olive, poplar and elm. Weeds were lily (Liliaceae), sedges (Cyperaceae), Mallows (Malvaciaea), pigmyweeds (Crassulaceae), the daisy family (Asteraceae), mugwort (Artemisia) sorrel (Rumex) and caltrops (Zygophyllaceous). Sedges were the dominant weeds. Moulds were low.
Kimberley
Grasses increased to moderate concentrations. Tree pollen identified was Australian pine (Casuarina). Weeds were spurges (Euphorbia), the daisy family (Asteraceae), mugwort (Artemisia), sedges (Cyperaceae), goosefoot (Chenopodiaceae) and sorrel (Rumex). Moulds were extremely low.
Durban
No tree pollen was detected and grass and weed pollen was low. Weeds identified were ragweed (Ambrosia). Sedges (Cyperaceae), nettle (Urticaceae) and ferns (Polypodiaceae). Moulds were high with strong, consistent peaks for ascospores, basidiospores (includes mushrooms) and the allergenic mould Cladosporium, during this wet and humid period with heavy rain.
Gqeberha
Grasses are increasing. Trees were low and included olive (Oleaceae), pine (Pinaceae) and karee (Rhus/Searsia). Weeds were pigweeds (Amaranthaceae), the daisy family (Asteraceae), the carnation family (Caryophyllaceae), reeds (Restionaceae), plantain (Plantaginaceae) and goosefoot (Chenopdiaceae). Moulds were low.
Potchefstroom
Grasses are increasing at this site. Trees were not significant and included elm (Ulmaceae), gum (Myrtaceae), birch (Betulaceae) and plane (Platanaceae), Weeds were maize (Zea mays), plantain (Plantaginaceae) and bulrush (Typhaceae), Moulds were low. Spikes for elm have been seen at this site since December.
George
Tree, grass and weed pollen concentrations were negligible. Trees were palm (Arecaceae), pine (Pinaceae), acacia (Acacia-type) and elm (Ulmaceae. Weeds were knotweed (Persicaria), erica (Ericaceae), goosefoot (Chenopodiaceae), plantain (Plantaginaceae), sedges (Cyperaceae) and citrus (Rutaceae). Moulds were low with large spikes for ascospores, which appear after rain.
