caused by Golovinomyces (syn. Erysiphe ) cichoracearum (DC.) V.P. Heluta ( Troisi et al., 2010 ) or Podosphaera xanthii Braun and Shishkoff (syn. P. fusca ) ( Chen et al., 2007 ; Kloos et al., 2004 ). Both of these fungi form a network of hyphae
bamboo poles. Table 1. Summary disease ratings and mean disease reactions of six bitter gourd breeding lines and a susceptible control (THMC 144) to cucurbit powdery mildew incited by Podosphaera xanthii in field tests at 12 locations in five countries
Cucurbit powdery mildew (CPM), a major problem of melon ( Cucumis melo L.) production worldwide, is mostly caused by two fungi: Podosphaera xanthii and Golovinomyces cichoracearum (DC) V.P. Heluta (formerly Erysiphe cichoracearum ) ( Jahn et
( Sitterly, 1978 ). CPM is caused by two fungal species, Podosphaera xanthii (formerly known as Sphaerotheca fuliginea Schlech ex Fr.Poll.) and Golovinomyces cichoracearum (formerly known as Erysiphe cichoracearum DC ex Merat.). P . xanthii has
Powdery mildew is a serious disease of melon (Cucumis melo L.) worldwide. Twenty-two melon cultigens have been used to define 22 reported races of the pathogen Podosphaera xanthii (sect. Sphaerotheca) xanthii (Castag.) U. Braun & N. Shish. Comb. nov. [syn. Sphaerotheca fuliginea (Schlecht. ex Fr.) Poll.]. Discrepancies in the reactions of eight cultigens to populations of P. xanthii races 1 and 2 in California, Japan, and Spain revealed genetic differences among them that can be used to differentiate P. xanthii race 1 and 2 populations in these countries. Implicit in these results is the existence of previously unknown virulence factors in these populations of P. xanthii races 1 and 2 that permit designation of new races of P. xanthii on melon. Synthesis of these results with previous reports resulted in the identification of 28 putative races of P. xanthii on melon that include eight variants of race 1 and six variants of race 2. Six of the cultigens exhibited resistant blisters in response to heavy infection by P. xanthii in field and greenhouse tests.
mildew incited by Podosphaera xanthii (Castagne) U. Braun & N. Shishkoff ( Shishkoff, 2000 ) and the yellowing incited by Cucurbit yellow stunting disorder virus (CYSDV) and the incidence of the cotton-melon aphid, Aphis gossypii are three of the
spread of fungicide-resistant Podosphaera xanthii and will offer growers options for disease control. P. xanthii and Golovinomyces cichoracearum (D.C.) V.P. Heluta (formerly Erysiphe cichoracearum D.C.) are the predominant fungi that cause powdery
associated chlorotic spots ( Davis et al., 2001 ). Podosphaera xanthii and Golovinomyces cichoracearum (D.C.) V.P. Heluta (formerly Erysiphe cichoracearum D.C.) are the predominant fungi that incite powdery mildew in cucurbits. These organisms differ
primary hyphae) × 100 / [∑ (conidia with germ tube only) + ∑ (conidia with germ tube and primary hyphae)]. Fig. 2. Development of Podosphaera xanthii conidia on cucumber seedlings acclimatized to red-to-far-red ratio of 1.2. ( A ) Conidium with a germ
gerbera is caused mainly by Podosphaera ( Sphaerotheca ) xanthii (syn. Podosphaera fusca ) ( Braun et al., 2002 ; Granke et al., 2012 ; Kloos et al., 2005 ; Moyer and Peres, 2012 ). The fungus forms a network of hyphae over the plant surface, and