Weekly Report

20 May 2022

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

An increase in tree pollen was seen in Cape Town, with an increase in weed pollen in Pretoria. Grass counts were moderate in Kimberley and likely similar in Bloemfontein (no new data available). High fungal spore counts were recorded for Cape Town and Durban.

Cape Town

High fungal spore counts were seen. Grass and weed pollen counts were low, with tree counts approaching significance. Tree pollen included the sumac family (Anacardiaceae), Australian pine (Casuarina sp.), cypress (Cupressaceae), waxberry (Morella sp.), gum (Myrtaceae) and forest elder (Nuxia sp.). The weeds detected were the daisy family (Asteraceae), erica (Ericaceae), fern spores (Polypodiaceae), sorrel (Rumex sp.) and nettles (Urticaceae).

Calvinia

Due to a technical fault at this site, no new data were available and the results from last week are repeated. Moderate grass counts with low tree, weed and mould levels were detected during this sampling period. Tree pollen included only the sumac family (Anacardiaceae) and bushwillow (Combretaceae). The daisy family (Asteraceae), goosefoot (Chenopodiaceae) and nettles (Urticaceae) were seen in the weeds category.

Johannesburg

Due to a technical fault at this site, no new data were available and the results from last week are repeated. Very low pollen and mould counts were seen. Tree pollen included olive (Oleaceae), lindens (Tiliaceae) and elm (Ulmaceae). The weeds detected were pigweed (Amaranthus sp.), the daisy family (Asteraceae) and erica (Ericaceae).

Pretoria

Grass, tree and fungal spore levels were low. Weeds approached significance due to increased daisy (Asteraceae) counts. Other weeds detected were the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae), erica (Ericaceae), sedges (Cyperaceae), spurges (Euphorbiaceae), fern spores (Polypodiaceae) and slangbos (Stoebe-type). Tree pollen included acacia (Acacia-type), bushwillow (Combretaceae), cypress (Cupressaceae), ash (Fraxinus sp.), mulberry (Moraceae), gum (Myrtaceae), plane (Platanus sp.), oak (Quercus sp.), willow (Salix sp.) and elm (Ulmaceae).

Bloemfontein

Due to a technical fault at this site, no new data were available and the results from last week are repeated. Moderate grass levels with low tree, weed and mould counts were seen. Tree pollen included the sumac family (Anacardiaceae), cypress (Cupressaceae), mulberry (Moraceae), gum (Myrtaceae) and pine (Pinaceae). The weeds detected were mugwort (Artemisia sp.), the daisy family (Asteraceae) and nettles (Urticaceae).

Kimberley

Tree, weed and grass pollen loads were light during this sampling period. Trees detected were karee (Rhus/Searsia sp.), the sumac family (Anacardiaceae) and cypress (Cupressaceae). Weeds included the daisy family (Asteraceae), goosefoot (Chenopodiaceae) and ferns (Polypodiaceae). Moulds were low, with small spikes for Cladosporium.

Durban

High spikes of ascospores were recorded in the fungal spore category towards the end of the week. Low grass, tree and weed pollen levels were seen. Trees included cypress (Cupressaceae), forest elder (Nuxia sp.), the sumac family (Anacardiaceae), gum (Myrtaceae), waxberry (Morella sp.) and mulberry (Moraceae). The weeds were ragweed (Ambrosia sp.), the daisy family (Asteraceae), goosefoot (Chenopodiaceae), fern spores (Polypodiaceae) and nettles (Urticaceae).

Gqeberha

Due to a technical fault at this site, no new data were available and the results from last week are repeated. All categories of pollen were low during this period. Waxberry (Morella sp.) was the only tree detected and slangbos (Stoebe-type) was the only weed identified. Mould loads were slight.