Weekly Report

20 January 2023

City
Overall Risk
Tree Pollen
Grass Pollen
Weed Pollen
Mould Spores

Pollen trigger alerts during this sampling period:

Grass pollen is increasing in some of the summer rainfall areas and was moderate in Johannesburg, Pretoria, Bloemfontein and Kimberley. Tree pollen was moderate in Bloemfontein. Weed pollen was moderate in Johannesburg and Bloemfontein. Significant trees were olive (Oleaceae) and elm (Ulmaceae) and significant weeds were plantain species (Plantaginaceae) and sedges (Cyperaceae). Fungal spores/moulds were low at all pollen sampling sites throughout South Africa.

Cape Town

Moderate tree and weed concentrations, with low grass values, were recorded. The trees present were birch (Betulaceae), cypress (Cupressaceae), the pea family (Fabaceae), mulberry (Moraceae), olive (Oleaceae), pine (Pinaceae), and elevated levels of karee (Rhus/Searsia sp.) and gum (Myrtaceae). Weeds included the daisy family (Asteraceae), sedges (Cyperaceae), goosefoot (Chenopodiaceae), erica (Ericaceae), fern (Polypodiaceae), plantain (Plantaginaceae), protea (Proteaceae), bulrush (Typhaceae) and nettles (Urticaceae). Moulds were very low.

Calvinia:

No findings due to spore trap malfunction. The most recent report and figures from the same time period last year are shown. Tree, grass and weed pollen was scanty during this sampling period. Trees detected included bushwillow Combretaceae) and weeds were goosefoot (Chenopodiaceae), ragweed (Ambrosia spp.), knotweed (Persicaria spp.) and mezereum (Thymelaeaceae). Moulds were very low. Tree pollen that may be seen in January includes waxberry (Morella spp.). In the category of weeds the daisy family (Asteraceae) and the pea family (Fabaceae) appear at this time of year.

Johannesburg

Grass concentrations were moderate and low levels of maize (Zea mays) are noted. Low tree levels included birch (Betulaceae), hackberry (Celtis spp.), gum (Myrtaceae), poplar (Populaceae), karee (Rhus/Searsia), bushwillow (Combretaceae) and olive (Oleaceae). Moderate weed pollen included goosefoot the daisy family the carnation family (Caryophyllacea), sedges (Cyperaceae), ferns (Polypodiaceae) and bulrush (Typhaceae). Moulds were low.

Pretoria

Grasses were moderate. Low tree levels included birch (Betulaceae), chestnut (Hippocastanaceae), cypress (Cupressaceae), Cape holly (Ilex), jacaranda (Fabaceae), mulberry (Moraceae), gum (Myrtaceae), karee (Rhus/Searsia spp.) and olive (Oleaceae). Weeds included the daisy family (Asteraceae), sedges (Cyperaceae), spurges (Euphorbiaceae), the carnation family (Caryophyllaceae), gentians (Geranaceae) and ferns (Polypodiaceae. Moulds were low.

Bloemfontein

Grass pollen concentrations were moderate. Tree levels were also moderate and the types detected were acacia (Acacia spp.), false olive (Buddleja), ash (Fraxinus spp.,) gum (Myrtaceae), olive (Oleaceae),  yellowwood (Podocarpaceae),  karee (Rhus/Searsia spp.) and elm (Ulmaceae). Weeds were pigmyweeds (Crassulaceae), sedges (Cyperaceae) and plantain (Plantaginaceae). Moulds were low.

Kimberley

Grasses were moderate. Low tree pollen levels included only Australian oak (Casuarina spp.). Weeds were goosefoot (Chenopodiaceae), the daisy family (Asteraceae) and mezereum (Thymelaeaceae.  Moulds were low.

Durban

Tree, grass and weed pollen was low during this sampling period. Trees detected included monkey puzzle (Araucariaceae), peppertree (Schinus spp.), gum (Myrtaceae) the sumac family (Anacardiaceae), olive (Oleaceae), waxberry (Morella spp.) and mulberry (Moraceae). Weeds were the daisy family (Asteraceae), sedges (Cyperaceae), nettles  (Urticaceae), knotweed (Persicaria spp.) ragweed (Ambrosia spp.), goosefoot (Chenopodiaceae) mezereum (Thymelaeaceae) and bulrush (Typhaceae). Moulds were low, during a week with high temperatures and no rain.

Gqeberha

Low pollen concentrations in all the categories: trees grasses and weeds were low. Trees detected included included Australian pine (Casuarina spp.), gum (Myrtaceae) and cedar (Pinaceae). Weeds were the carnation family (Caryophyllaceae) only. Moulds were low

Potchefstroom:

No findings due to spore trap malfunction.