Weekly Report

8 September 2023

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Tree pollen increased in Johannesburg, Bloemfontein, Pretoria and Potchefstroom. Rain diminished the pollen concentrations in Cape Town. The dominant trees are plane, mulberry, olive, ash, and African stinkwood. Grasses, weeds and moulds were low.

Cape Town

Several days with heavy rain affected the pollen catch. On sunshine days total tree counts reached 188. Cypress (Cupressaceae) is the dominant pollen in Cape Town but plane (Platanaceae), pine (Pinaceae), walnut (Juglandaceae), olive (Oleaceae) and gum (Myrtaceae) are releasing large amounts of pollen. Other flowering trees were the sumac family (Anacardiaceae), acacia (Acacia spp.), oak (Quercus spp.) and poplar (Populaceae). Weeds were erica (Ericaceae), goosefoot (Chenopodiaceae) and sedges (Cyperaceae). Grasses and moulds were low, inhibited by low temperatures.

Calvinia

This site is not operational.

Johannesburg

High tree concentrations were dominated by plane (Platanaceae), African stinkwood Celtis spp) and mulberry (Moraceae). Other flowering trees were palm (Arecaceae), cypress (Cupressaceae), bushwillow (Combretaceae), beech (Fagus spp.), ash (Fraxinus spp.), sweetgum (Liquidamber spp.) gum (Myrtaceae), pine (Pinaceae), yellowwood (Podocarpaceae), oak (Quercus spp.) karee (Rhus/Searsia), star apple (Sapotaceae), willow (Salicaceae) and elm (Ulmaceae). Weeds were pigweed (Amaranthaceae) and spurges (Euphorbiaceae). Grasses and moulds were low.

Pretoria

High tree pollen concentrations were dominated by mulberry (Moraceae), plane (Platanaceae) and birch (Betulaceae). Other flowering trees included African stinkwood (Celtis spp.), Australian pine (Casuarina spp.), cypress (Cupressaceae), ash (Fraxinus spp.), gum (Myrtaceae), pine (Pinaceae), poplar (Populaceae), oak and karee (Rhus/Searsia spp.). Grasses were very low, as were moulds and no weed pollen was detected.

Bloemfontein

Tree concentrations were high and the dominant tree here were mulberry (Moraceae), olive (Oleaceae), ash (Fraxinus spp) and plane (Platanaceae). Other contributing trees were birch (Betulaceae), African stinkwood (Celtis spp), cypress (Cupressaceae), gum (Myrtaceae), poplar ({Populaceae), pine (Pinaceae) and yellowwood (Podocarpaceae). Grasses and moulds were low. Weeds were moderate and included the daisy family (Asteraceae), pigmy weeds (Crassulaceae) and sedges (Cyperaceae).

Kimberley

The spore trap strip did not reach UCT in time for processing so last week’s findings are repeated: Low pollen and mould concentrations were recovered during this sampling week, but on one  spp.), cypress (Cupressaceae), pine (Pinaceae), bushwillow (Combretaceae) and mulberry (Moraceae). Weeds were goosefoot (Chenopodiaceae) and the daisy family (Asteraceae). Moulds were very low.

Durban

Low pollen concentrations in all three categories were detected this week. Trees included mulberry (Moraceae) and pine (Pinaceae) and weeds were the carnation family (Caryophyllaceae) and knotweed. Moulds were low.

Gqeberha

No findings were received from this site.

Potchefstroom

High tree pollen concentrations were dominated by plane (Platanaceae) and mulberry (Moraceae). Cypress (Cupressacae) is declining. Other flowering trees included African stinkwood (Celtis spp.), pine (pinaceae), oak (Quercus spp.) and birch (Betulus). Weeds were the daisy family (Asteraceae). Grasses and moulds were low.

George

Rain reduced the pollen catch at this sampling site but on warm days tree pollen increased to moderate levels and grasses approached the significant threshold. Tree pollen included the sumac family (Anacardiaceae), black walnut (Juglandaceae), cypress (Cupressaceae), pine (Pinaceae), yellowwood (Podocarpaceae), willow (Salicaceae), poplar (Populaceae), birch (betulaceae) and cedar (Cedrus spp.). Weeds were goosefoot (Chenopdiaceae), mallows (Malvaceae), sedges (Cyperaceae) and erica (Ericaceae). Fungal spores were low. The dominant trees are pine and yellowwood.