Weekly Report

16 April 2022

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Summary

Grass levels have decreased across the country, as moderate counts were only seen in Kimberley and Bloemfontein during this sampling period. Tree pollen was moderate in Cape Town and Durban, while moderate weed levels were detected in Cape Town and Bloemfontein. Moulds in Durban continue to be significant.

Cape Town

Grass counts were low, with tree and weed levels approaching significance. Tree pollen included birch (Betulaceae), waxberry (Myricaceae), gum (Myrtaceae), karee (Rhus/Searsia sp.), buckthorns (Rhamnaceae) and elm (Ulmaceae).  The weeds detected were the daisy family (Asteraceae), the carnation family (Caryophyllaceae), goosefoot (Chenopodiaceae), sedges (Cyperaceae), erica (Ericaceae), the iris family (Iridaceae), mallows (Malvaceae), plantain (Plantaginaceae), the rose family (Rosaceae), bulrush (Typhaceae), sorrel (Rumex sp.) and nettles (Urticaceae). Moulds were low.

Calvinia

Grass and weed pollen levels were very low and no tree pollen was detected during this sampling period. Weeds included only goosefoot (Chenopodiaceae). Moulds were very low.

Johannesburg

Pollen in all three categories were low. Pine (Pinaceae) and elm (Ulmaceae) were the only tree pollen types detected. Weeds included the daisy family (Asteraceae), sedges (Cyperaceae), erica (Ericaceae) and fern spores (Polypodiaceae). Moulds were low.

Pretoria

Grass, weed and tree pollen levels were low during this sampling period. Tree pollen included birch (Betulaceae), cypress (Cupressaceae), ash (Fraxinus sp.), mulberry (Moraceae) and plane (Platanus sp.). Weeds detected were the daisy family (Asteraceae), goosefoot (Chenopodiaceae), spurges (Euphorbiaceae) and ferns (Polypodiaceae). Moulds were also low.

Bloemfontein

No new data were available due to courier delays. The results from the previous sampling period is repeated. Significant grass and weed pollen counts were seen, with low tree and mould counts. The tree types detected were acacia (Acacia sp.), birch (Betulaceae), hackberry (Celtis sp.), waxberry (Morella sp.) and olive (Oleaceae). Weeds were dominated by sedges (Cyperaceae) and also included the daisy family (Asteraceae), goosefoot (Chenopodiaceae), pigmy weeds (Crassulaceae), plantain (Plantaginaceae) and fern spores (Pteridaceae).

Kimberley

Grasses ranged from low to high during this sampling period. Low tree pollen levels were detected and karee (Rhus/Searsia sp.) was the only tree taxon found. Weeds were similarly low and included the daisy family (Asteraceae), goosefoot (Chenopodiaceae), sedges (Cyperaceae) and plantain (Plantaginaceae). Moulds were generally low, but strong spikes for ascospores and the allergenic mould Cladosporium occurred after rain.

Durban

Moulds were high and peaks of ascospores and basidiospores were seen. Grass and weed pollen levels were low, with tree levels approaching significance. The tree pollen detected was birch (Betulaceae), Australian pine (Casuarina sp.), bushwillow (Combretaceae), ash (Fraxinus sp.), mulberry (Moraceae) and gum (Myrtaceae). Weed pollen included ragweed (Ambrosia sp.), the daisy family (Asteraceae), plantain (Plantaginaceae), ferns (Polypodiaceae), proteas (Proteaceae), the nightshade family (Solanaceae) and nettles (Urticaceae).

Gqeberha

All pollen categories as well as fungal spore counts were very low. Only Australian pine (Casuarina sp.) was detected in the trees category, and weeds included the carnation family (Caryophyllaceae), sedges (Cyperaceae) and slangbos (Stoebe-type).

 

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