Summary
Low pollen loads were found from all the sites in the South African Pollen Monitoring network (SAPNET) this week. Ragweed (Ambrosia spp.) was detected from the air of Durban, Pretoria and Kimberley in low numbers, indicating that the sources were distant, as ragweed pollen is small and light and can travel long distances. Moulds/fungal spores were low during this hot period and high temperatures possibly inhibited grass pollen release.
Cape Town
Grass counts remained low at this site. Low tree counts included gum (Myrtaceae), peppertree (Schinus spp.) maple (Acer spp.),and pine (Pinaceae). Weeds detected were knotweed (Persicaria spp.), goosefoot (Chenopodiaceae), bulrush (Typhaceae), buckwheat (Polygonaceae), ferns (Polypodiaceae) and nettles (Urticaeae). Moulds were low during this hot period with little rain.
Calvinia
The spore trap is being repaired. Findings from previous sampling are shown and are similar to those of Cape Town. Tree pollen typically detected in late summer are karee (Searsia/Rhus spp.). Weeds previously found in late January are the daisy family (Asteraceae), the pea family (Fabaceae) and the mustard or cabbage family (Brassicaceae). Moulds are usually low in hot, dry weather.
Johannesburg
Grass pollen was low. Low tree levels included acacia (Acacia spp.), birch (Betulaceae), Australian pine (Casuarina spp), bushwillow (Combretaceae), olive (Oleaceae), yellowwood(Podocarpaceae), and poplar (Populaceae). Low weeds were detected and these were pigweed (Amaranthaceae), the daisy family (Asteraceae), the carnation family (Caryophyllaceae), sedge (Cyperaceae), lily (Liliaceae), fern (Polypodiaceae), bulrush (Typhaceae) and the carrot, celery and parsley family (Apiaceae). Moulds were very low.
Pretoria
No grass pollen was detected at this site during this sampling period. Trees were birch (Betulaceae), cypress (Cupressaceae), Cape Holly (Ilex spp.) ash (Fraxinus spp.) and mulberry (Moraceae). Weeds were ragweed (Ambrosia spp.) mugwort (Artemisia spp.), aloe (Asphodelaceae) and mint (Lamiaceae). Moulds were low.
Bloemfontein
Grasses were moderate. Tree counts were low and included bushwillow (Combretaceae), mulberry (Moraceae), olive (Oleaceae), gum (Myrtaceae), pine (Pinaceae), poplar (Populaceae), karee (Searsia/Rhus spp.) and elm (Ulmaceae). Low weed levels included the daisy family (Asteraceae), goosefoot (Chenopodiaceae), pigmyweeds (Crassulaceae), sedge (Cyperaceae) and plantain (Plantaginaceae). Moulds were low.
Kimberley
Tree, grass and weed pollen levels were low. Only peppertree (Schinus spp) was detected for trees. Weeds were ragweed (Ambrosia spp.), goosefoot (Chenopodiaceae) and ferns (Polypodiaceae). Moulds were low but approached the significant threshold as spikes occurred for the allergenic spore Cladosporium as well as for ascospores.
Durban
Tree, grass and weed pollen levels were low. Trees detected were mulberry (Moraceae), gum (Myrtaceae) and karee (Searsia/Rhus spp.). Weeds included sedge (Cyperaceae), ferns (Polypodiaceae), ragweed (Ambrosia spp.), the daisy family (Asteraceae), bulrush (Typhaceae) and nettles (Urticaceae). Moulds were low but were close to the significant threshold with spikes for the allergenic mould Cladosporium.
Gqeberha
Tree, grass and weed pollen counts were low. Trees identified included Australian pine (Casuarina spp.) and in the weed pollen category only pigweeds (Amaranthus spp) were detected. Moulds were low.
Potchefstroom: There are no findings but repairs to the spore trap are going well.
