Summary
Grasses in the summer rainfall areas are decreasing except for Kimberley, where grasses continue their upward trend. Weeds and trees are low at all sites.
Cape Town
Low grasses, trees and weeds were seen. Trees included waxberry (Morella) and elm (Ulmaceae). Weeds were goosefoot (Chenopodiaceae), the daisy family (Asteraceae) and nettles (Urticaceae). Moulds were low.
Johannesburg Central
Pollen concentrations decreased at this site. Grasses were low. Low trees included false olive (Buddleia), persimmon (Ebenaceae), olive (Oleaceae), gum (Myrtaceae), pine (Pinaceae) and cypress (Cupressaceae). Low weeds included pigweeds (Amaranthaceae), the daisy family (Asteraceae) and sedges (Cyperaceae). Moulds were low.
South of Johannesburg (Vanderbijlpark)
Grass concentrations were moderate. Low trees included only birch (Betulus). Weeds were pigweed (Amaranthaceae), the daisy family (Asteraceae) and sedges (Cyperaceae). Moulds were low.
Pretoria
Grasses are usually moderate at this time of the year. Low tree concentrations would include mulberry (Moraceae), bushwillow (Combretaceae), white stinkwood (Celtis), karee (Rhus/Searsia) and willow (Salicaceae). Weeds might be the daisy family (Asteraceae), goosefoot (Chenopodiaceae), sedges (Cyperaceae), ericas (Ericaceae) and ferns (Polypodiaceae). Moulds are low. 5-yr means are shown.
Bloemfontein
Grass pollen at this site is generally high at this time of the year. Trees would be mulberry (Moraceae), poplar (Populaceae), elm (Ulmaceae), olive (Oleaceae) and acacia (Acacia-type). Weeds are likely to be pigmyweeds (Crassulaceae), sedges (Cyperaceae), plantain (Plantaginaceae), goosefoot (Chenopodiaceae) and ferns (Polypodiaceae). Moulds are low. 5-year means are shown.
Kimberley
High concentrations of grasses were seen. Low trees included monkey puzzle (Araucariaceae). Weeds were goosefoot (Chenopodiaceae). Moulds were low, but spikes for ascospores appeared in the air flowing rain.
Durban
Tree, grass and weed pollen concentrations were low at this site. No tree pollen was detected. Weeds included ragweed (Ambrosia) and ferns (Polypodicaeae). Moulds were moderate with strong spikes for ascospores, following rain.
Gqeberha
Grass, tree and weed pollen concentrations were low. Trees included persimmon (Ebenaceae), waxberry (Morella), gum (Myrtaceae) and karee (Rhus/Searsia). Weeds were goosefoot (Chenopodiaceae), sedges (Cyperaceae) and slangbos (Stoebe-type). Moulds were low.
George
Low concentrations were seen for all pollen categories. Trees included olive (Oleaceae), ash (Fraxinus) and waxberry (Morella). Moulds were low. Last year’s findings for the third week in March are shown as the spore trap is malfunctioning, but the repair of this spore trap will be completed next week.
Reference Range
Grass: Low: 0-5 Moderate: 6-20 High: 21-200
Trees: Low: 0-15 Moderate: 16-90 High: 91-1500
Weeds: Low: 0-10 Moderate: 10-50 High: 51-500
Moulds: Low: 0-900 Moderate: 900-2500 High 2500-25000
Unit: per cubic metre
