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Trunk disease fungal pathogens reduce olive production globally by causing cankers, dieback, and other decline-related symptoms on olive trees. Very few fungi have been reported in association with olive dieback and decline in South Africa. Many of the fungal species reported from symptomatic olive trees in other countries have broad host ranges and are known to occur on other woody host plants in the Western Cape province, the main olive production region of South Africa. This survey investigated the diversity of fungi and symptoms associated with olive dieback and decline in South Africa. Isolations were made from internal wood symptoms of 145 European and 42 wild olive trees sampled in 10 and 9 districts, respectively. A total of 99 taxa were identified among 440 fungal isolates using combinations of morphological and molecular techniques. A new species of Pseudophaeomoniella, P. globosa, had the highest incidence, being recovered from 42.8 % of European and 54.8 % of wild olive samples. This species was recovered from 9 of the 10 districts where European olive trees were sampled and from all districts where wild olive trees were sampled. Members of the Phaeomoniellales (mainly P. globosa) were the most prevalent fungi in five of the seven symptom types considered, the only exceptions being twig dieback, where members of the Botryosphaeriaceae were more common, and soft/white rot where only Basidiomycota were recovered. Several of the species identified are known as pathogens of olives or other woody crops either in South Africa or elsewhere in the world, including species of Neofusicoccum, Phaeoacremonium, and Pleurostoma richardsiae. However, 81 of the 99 taxa identified have not previously been recorded on olive trees and have unknown interactions with this host. These taxa include one new genus and several putative new species, of which four are formally described as Celerioriella umnquma sp. nov., Pseudophaeomoniella globosa sp. nov., Vredendaliella oleae ge

Trunk disease fungal pathogens reduce olive production globally by causing cankers, dieback, and other decline-related symptoms on olive trees. Very few fungi have been reported in association with olive dieback and decline in South Africa. Many of the fungal species reported from symptomatic olive trees in other countries have broad host ranges and are known to occur on other woody host plants in the Western Cape province, the main olive production region of South Africa. This survey investigated the diversity of fungi and symptoms associated with olive dieback and decline in South Africa. Isolations were made from internal wood symptoms of 145 European and 42 wild olive trees sampled in 10 and 9 districts, respectively. A total of 99 taxa were identified among 440 fungal isolates using combinations of morphological and molecular techniques. A new species of Pseudophaeomoniella, P. globosa, had the highest incidence, being recovered from 42.8 % of European and 54.8 % of wild olive samples. This species was recovered from 9 of the 10 districts where European olive trees were sampled and from all districts where wild olive trees were sampled. Members of the Phaeomoniellales (mainly P. globosa) were the most prevalent fungi in five of the seven symptom types considered, the only exceptions being twig dieback, where members of the Botryosphaeriaceae were more common, and soft/white rot where only Basidiomycota were recovered. Several of the species identified are known as pathogens of olives or other woody crops either in South Africa or elsewhere in the world, including species of Neofusicoccum, Phaeoacremonium, and Pleurostoma richardsiae. However, 81 of the 99 taxa identified have not previously been recorded on olive trees and have unknown interactions with this host. These taxa include one new genus and several putative new species, of which four are formally described as Celerioriella umnquma sp. nov., Pseudophaeomoniella globosa sp. nov., Vredendaliella oleae ge

Nineteen Phaeoacremonium species are currently known in South Africa. These have been reported from grapevines, fruit trees, fynbos twig litter and arthropods. In other countries some of these Phaeoacremonium species are also known from hosts such as European olive, quince and willow that commonly occur in the Western Cape Province of South Africa, where most South African records of Phaeoacremonium have been made. The aim of this study was to investigate the species diversity and host-range of Phaeoacremonium in the Western Cape Province of South Africa by characterising 156 isolates collected from 29 woody hosts. Phylogenetic analyses of combined actin and beta-tubulin datasets allowed for the identification of 31 species among the 156 isolates, including 13 new species and 3 known species that had not been recorded in South Africa previously. The new Phaeoacremonium species include P. album, P. aureum, P. bibendum, P. gamsii, P. geminum, P. junior, P. longicollarum, P. meliae, P. oleae, P. paululum, P. proliferatum, P. rosicola and P. spadicum. All previous records of P. alvesii in South Africa were re-identified as P. italicum, but both species were recovered during this survey. A total of 35 described Phaeoacremonium species are now known from South Africa, more than double the number reported from any other country. This high diversity reflects the high diversity of indigenous flora of the Cape Floral Region, a biodiversity hotspot mainly situated in the Western Cape Province. Paraphyly and incongruence between individual phylogenies of the actin and beta-tubulin regions complicated species delimitation in some cases indicating that additional phylogenetic markers should be investigated for use in Phaeoacremonium phylogenies to prevent misidentifications and the introduction of vague species boundaries.

Nineteen Phaeoacremonium species are currently known in South Africa. These have been reported from grapevines, fruit trees, fynbos twig litter and arthropods. In other countries some of these Phaeoacremonium species are also known from hosts such as European olive, quince and willow that commonly occur in the Western Cape Province of South Africa, where most South African records of Phaeoacremonium have been made. The aim of this study was to investigate the species diversity and host-range of Phaeoacremonium in the Western Cape Province of South Africa by characterising 156 isolates collected from 29 woody hosts. Phylogenetic analyses of combined actin and beta-tubulin datasets allowed for the identification of 31 species among the 156 isolates, including 13 new species and 3 known species that had not been recorded in South Africa previously. The new Phaeoacremonium species include P. album, P. aureum, P. bibendum, P. gamsii, P. geminum, P. junior, P. longicollarum, P. meliae, P. oleae, P. paululum, P. proliferatum, P. rosicola and P. spadicum. All previous records of P. alvesii in South Africa were re-identified as P. italicum, but both species were recovered during this survey. A total of 35 described Phaeoacremonium species are now known from South Africa, more than double the number reported from any other country. This high diversity reflects the high diversity of indigenous flora of the Cape Floral Region, a biodiversity hotspot mainly situated in the Western Cape Province. Paraphyly and incongruence between individual phylogenies of the actin and beta-tubulin regions complicated species delimitation in some cases indicating that additional phylogenetic markers should be investigated for use in Phaeoacremonium phylogenies to prevent misidentifications and the introduction of vague species boundaries.

The recovery of fine hydrophilic gangue in flotation is related to the recovery of water. Water is carried by bubbles into and through the froth. The amount transported (entrained) depends on bubble size, gas rate and the subject of this paper, frother type. To isolate the effect of frother type from that of bubble size, gas holdup is used as the correlating variable. Measurements were made using a bubble column (no solids) operated continuously with the overflow recycled. Using an automatically controlled 7 cm foam depth, the overflow rate of water is used as a measure of water-carrying rate. It is shown that the common frothers can be grouped into four families on the basis of the relationship between water-carrying rate and gas holdup. These are, from lowest to highest water-carrying rate for a given gas holdup: pentanol; heptanol, hexanol, MIBC and DF200; octanol, ethoxylated C6 alcohol and DF250; and F150., The recovery of fine hydrophilic gangue in flotation is related to the recovery of water. Water is carried by bubbles into and through the froth. The amount transported (entrained) depends on bubble size, gas rate and the subject of this paper, frother type. To isolate the effect of frother type from that of bubble size, gas holdup is used as the correlating variable. Measurements were made using a bubble column (no solids) operated continuously with the overflow recycled. Using an automatically controlled 7 cm foam depth, the overflow rate of water is used as a measure of water-carrying rate. It is shown that the common frothers can be grouped into four families on the basis of the relationship between water-carrying rate and gas holdup. These are, from lowest to highest water-carrying rate for a given gas holdup: pentanol; heptanol, hexanol, MIBC and DF200; octanol, ethoxylated C6 alcohol and DF250; and F150.

A colorimetric analytical technique originally developed for characterising phenols and adapted for methyl isobutyl carbinol has been successfully extended to almost the full range of commercial frothers. Observations from plant surveys have confirmed the technique's effectiveness and robustness. Characterisation of frothers has taken two routes, determining the water-carrying rate and investigating the properties of thin bubble films. The water-carrying rate and gas holdup at controlled froth depths were measured in a specially designed column and the relationship between carrying rate and gas holdup found to be approximately linear and dependent on frother type. Using a representative frother from the four families identified, the water-carrying rate at a given gas holdup was found to increase with film thickness. The implications of the findings for the role of frother in bubble production are discussed., A colorimetric analytical technique originally developed for characterising phenols and adapted for methyl isobutyl carbinol has been successfully extended to almost the full range of commercial frothers. Observations from plant surveys have confirmed the technique's effectiveness and robustness. Characterisation of frothers has taken two routes, determining the water-carrying rate and investigating the properties of thin bubble films. The water-carrying rate and gas holdup at controlled froth depths were measured in a specially designed column and the relationship between carrying rate and gas holdup found to be approximately linear and dependent on frother type. Using a representative frother from the four families identified, the water-carrying rate at a given gas holdup was found to increase with film thickness. The implications of the findings for the role of frother in bubble production are discussed.