Zacharias Pretorius

[Zacharias Pretorius @PretoriusZak]

@alabamaED @JDPretorius You are most welcome to use the pictures

[Zacharias Pretorius @PretoriusZak]

Bunch rot of Chardonnay grapes following a spell of wet weather in the Western Cape, ZA.
@JDPretorius
#Botrytiscinerea

[Zacharias Pretorius @PretoriusZak]

#Rust of #Ehrharta calycina. Probably #Uromyces quaggafonteinus according to Berndt & Wood (2012). From Wonderfontein, Northern Cape, ZA.

[Zacharias Pretorius @PretoriusZak]

#Rust on #Bromus pectinatus most likely caused by #Puccinia recondita. From Northern Cape, ZA. Any suggestions on the f. sp.?@striiformis, @wheatpath

[Zacharias Pretorius @PretoriusZak]

@_maya_jones @B12272396Willem @LandbouLisa There is no control of poplar rust as far as I know.

[Zacharias Pretorius @PretoriusZak]

Poplar #rust is a common and widespread disease of #Populus species in South Africa. Analysis of recent samples from the Western Cape and Free State provinces confirmed #Melampsora larici-populina in all cases. Thanks Botma Visser, @B12272396Willem and @LandbouLisa for helping.

[Zacharias Pretorius @PretoriusZak]

Common #bunt of #wheat (#Triticum aestivum) caused by #Tilletia laevis, a disease rarely seen in South Africa these days. From the 2024 wheat harvest, Northern Cape, ZA.

[Zacharias Pretorius @PretoriusZak]

@striiformis Thanks

[Zacharias Pretorius @PretoriusZak]

Yellow rust on leaves, sepals, and fruit of red raspberry (#Rubus idaeus). Infection levels were unexpectedly high at the end of a relatively dry summer. Looks like #Phragmidium rubi-idaei. From Western Cape, ZA.

[Zacharias Pretorius @PretoriusZak]

Privileged to have been part of the Wheat Rust Training team at Njoro, Kenya. Strong lecture component from international colleagues, appreciative trainees, and excellent field plots and greenhouse screening.
@MaricelisAceve1
@SridharBhavani

[Zacharias Pretorius @PretoriusZak]

#Blueberry (#Vaccinium sp.) #rust from Napier, Western Cape, ZA. Should be #Pucciniastrum minimum (= Thekopsora minima) according to a previous report.

[Zacharias Pretorius @PretoriusZak]

#Rust caused by #Puccinia lagenophorae on Namaqua daisy (#Dimorphotheca sinuata), Kamieskroon, Northern Cape, ZA.

[Zacharias Pretorius @PretoriusZak]

Pleased to announce our South African plant #rust image repository https://t.co/3hX2Pt0sLC on the International Day of Plant Health 2024. Thanks Emerson Del Ponte @edelponte, Lisa Rothmann @LandbouLisa, and Willem Boshoff @B12272396Willem for reviving our photographs.
#IDPH

[Zacharias Pretorius @PretoriusZak]

#Rust on kikuyu grass (#Pennisetum clandestinum, syn. #Cenchrus clandestinus) caused by #Phakopsora apoda (syn. #Angiopsora apoda). Paraphyses are abundant and a hyperparasite fairly common. From Onrus River, Western Cape, ZA.

[Plant Pathogens (APPS) @Plant_Pathogens]

New is our APP journal:

Pathogenicity of Puccinia porri on Allium in South Africa

https://t.co/IoBH7cItt2

[Zacharias Pretorius @PretoriusZak]

@striiformis @LandbouLisa Urediniospores from pustules on Dactylis leaves (left) and stems (right). Specimen may have mixed infection.

[Zacharias Pretorius @PretoriusZak]

#Rust on #Dactylis glomerata collected at Golden Gate National Park, Free State, ZA. Thanks @LandbouLisa for spotting this.

[Zacharias Pretorius @PretoriusZak]

#Puccinia oxalidis on #Oxalis latifolia (garden pink-sorrel) from Bloemfontein, South Africa.

[Zacharias Pretorius @PretoriusZak]

#Rust caused by #Puccinia thaliae on #canna lily. Hypophyllous uredinia with water-soaked lesions on upper surface. From Onrus River, Western Cape, ZA.

[Zacharias Pretorius @PretoriusZak]

#Stem rust of ryegrass (#Lolium) caused by #Puccinia graminis subsp. graminicola (Paarl, Western Cape, ZA). Mostly telia but a few urediniospores still present.