Summary
Grass pollen is increasing in some summer rainfall regions of South Africa. Increased grass levels were seen in Johannesburg, Pretoria and Kimberley. Tree and weed pollen levels are generally low. Moulds are increasing in response to higher humidity and cooler temperatures in some areas.
Cape Town
Tree and weed pollen concentrations were low at this site and no grass pollen was detected. Trees detected were gum (Myrtaceae), pine (Pinaceae), cypress (Cupressaceae) and elm (Ulmaceae). Small spikes were detected for elm. Weeds were knotweed (Persicaria spp.), goosefoot (Chenopodiaceae), sedge (Cyperaceae), the daisy family (Asteraceae) and rush (Juncaceae). Moulds were low but a strong increase in ascospores following rain.
Calvinia
Very low pollen concentrations were detected in the atmosphere during this sampling period for grasses, trees and weeds. Trees identified were waxberry (Morella spp.) and bushwillow (Combretaceae). Weeds were goosefoot. Moulds were extremely low.
Johannesburg
Grass concentrations in the atmosphere were moderate at this sampling site. Tree pollen was low and included Australian pine (Casuarina spp.) Cape Holly (Ilex spp.), pine (Pinaceae), gum (Myrtaceae) and elm (Ulmaceae). Weeds were pigweed (Amaranthaceae), mugwort (Artemisia spp.), the daisy family (Asteraceae), fern (Polypodiaceae), sedge (Cyperaceae), bulrush(Typhaceae) and the carnation family (Caryophyllaceae) Moulds were low.
Pretoria
Grasses were moderate. Low tree concentrations in the atmosphere included acacia (Acacia spp.), birch (Betulaceae), hackberry (Celtis spp.), cypress (Cupressaceae), mulberry (Moraceae), pine (Pinaceae), poplar (Populaceae), oak (Quercus spp.) and karee (Rhus/Searsia spp.). Weeds were the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae), sedge (Cyperaceae), erica (Ericaceae), fern (Polypodiaceae) and protea (Proteaceae). Moulds were low.
Bloemfontein
Low concentrations were detected for tree, grass and weed pollen. Trees were birch (Betulaceae), false olive (Buddleja), mulberry (Moraceae), gum (Myrtaceae), olive (Oleaceae), pine (Pinaceae), plane (Platanaceae) poplar (Populaceae) and karee (Rhus/ Searsia spp.). Weeds were the daisy family (Asteraceae), erica (Ericaceae), pigmy weeds (Crassulaceae), plantain (Plantaginaceae) and sedge (Cyperaceae). Moulds were very low.
Kimberley
The pollen strip failed to reach the laboratory for processing so last weeks findings are repeated. Kimberley: Grasses increased to moderate levels during this sampling period. Low tree concentrations included elm (Ulmaceae), peppertree (Schinus spp.), waxberry (Morella spp.), walnut (Juglanaceae), poplar (Populaceae) and olive (Oleaceae). Weed concentrations were low and included the daisy family (Asteraceae), goosefoot (Chenopodiaceae) and spurges (Euphorbiaceae). Moulds were low.
Durban
Grass concentrations were high on days without rain. Grasses were low but small spikes on some days were noted. Low tree pollen concentrations included cypress (Cupressaceae), mulberry (Moracreae), waxberry (Morella spp.), gum (Myrtaceae), elm (Oleaceae), walnut (Juglandaceae) and poplar (Populace). Weeds were the daisy family (Asteraceae), nettles (Urticaceae), mallows (Malvaceae), buckwheat (Polygonaceae), mezereum (Thymelaeaceae) and ferns (Polypodiaceae). Moulds were high.
Gqeberha
Very low pollen concentrations were observed at this site. Trees detected were only cypress (Cupressaceae) and weed pollen included only protea (Proteaceae). Moulds were low.
Potchefstroom
Grass concentrations in the air were moderate. Trees and weeds were low. Trees detected included Australian pine (Casuarina spp.), bushwillow (Combretaceae), cypress (Cupressaceae), waxberry (Morella spp.), gum (Myrtaceae), spruce (Picea spp.), and pine (Pinaceae). Weeds were pigweeds, (Amaranthaceae), the daisy family (Asteraceae), sedge (Asteraceae), Pellitory-of-the-wall (Parietaria spp.), knotweed (Persicaria spp.), plantain (Plantaginaceae) and nettle (Urticaceae. Moulds were low but were close to moderate levels.
