Rabi season problem of purple blotch alternaria porri and stemphylium blight stemphylium vesicarium, which again pulls down the productivity. Purple blotch, alternaria porri, causing spots on leaves of shallots. Largespored alternaria pathogens in section porri disentangled. Hence, the present study was undertaken to evaluate the. It is an important disease in warm, humid oniongrowing regions around the world. The best ways to manage the disease is to grow disease resistant varieties.
Dec 01, 2016 purple blotch, caused by alternaria porri ellis cifferi is the most destructive foliar disease, prevalent in all allium growing countries of the world kareem et al. A total of 43 allium genotypes were screened for purple blotch resistance under field conditions. Older leaves and plants are more susceptible to infection. Based on these positive results, in this study, we evaluated the potential of t. Oswaldo arnulfo ramosvergara1, luis eduardo gonzalezcepeda1, marcelino federico isaurojeronimo1 y dagoberto guillensanchez2. We do not use these to store personal information about you. Garlic and leeks may be affected as well as onions. Initial symptoms appear on older leaves, usually late in the summer as spores are blown from infested debris. Mancha purpura alternaria porri na cultura da cebola. Biological effectiveness of mirage procloraz for the control of purple blotch alternaria porri on onion. Pdf morphology of infection of onion leaves by alternaria porri. Article history evaluation of onion genotypes against purple.
Increased ploughing between seasons reduced the disease, probably by reducing the amount of soilborne inoculum gupta and pathak, 1987. Late varieties on the highveld and in northern areas are vulnerable as they will still be growing when the rainy season starts. The yield loss could vary from 25 to 50% quadri et al. The large spots are oval, purple and up to 150 mm long. Because many of the members of this group have similar morphology, alternaria dauci has also been classified as formae specialis of. Purple blotch, alternaria porri, on leaves of shallots showing zoned spots. Antracnosis colletotrichum truncatum 1 apply antracnosis colletotrichum truncatum filter. On potato leaves few spores were produced without induction, some by drying the conidiophorebearing leaves in darkness, more by exposing wet leaves to fluorescent. Kingdom fungi 1fungk phylum ascomycota 1ascop subphylum pezizomycotina. Image subid scientific name common name autid photographer org baseimgurl landscape description. It is responsible for causing severe yield losses ranging from 2. Natal submitted in fulfilment of the academic requirements for the degree of doctor of philosophy in the department of microbiology and plant pathology university of natal. Porri is the largest section, containing almost all alternaria species with medium to large conidia and long beaks, some of which are important plant pathogens e.
Article history evaluation of onion genotypes against. Purple blotch is caused by the fungus alternaria porri. Trichoderma asperellum, a potential biological control agent. Common onion diseases to watch out for farmers weekly. Efectividad biologica del fungicida mirage procloraz. Purple blotch, caused by alternaria porri ellis cifferi, is a serious disease incurring heavy yield losses in the bulb and seed crop of onion and garlic worldwide. Identification of novel source of resistance and differential. Although it can be seedborne, it usually starts off from crop residue. Evaluation of several fungicidas in the control of alternaria porri ellis cif. Development of selective media for the isolation and.
Trichoderma asperellum, a potential biological control. Alternaria porri moho negro aspergillus niger podredumbre del cuello botrytis aclada. On potato leaves few spores were produced without induction, some by drying the conidiophorebearing leaves in darkness, more by exposing wet leaves to fluorescent light and most by illuminating and drying the leaves. Malezas enfermedades plagas mancha purpura alternaria porri. The highest spore production ofstemphylium botryosum f. Effect of light on sporulation of alternaria porri f. Because many of the members of this group have similar morphology, alternaria dauci has also been classified as formae specialis of carrots, or a. Phytophthora porri foister, transactions of the botanical society of edinburgh 30. Alternaria porri altepooverview eppo global database.
Download fulltext pdf download fulltext pdf morphology of infection of onion leaves by alternaria porri article pdf available in canadian journal of botany 728. Documents about alternaria porri altepo this website uses cookies our website uses cookies to ensure that we give you the best possible online experience. Productos con alternaria en cebolla, pagina 1 informacion y precios. Continuing to use this website means you agree to our use of cookies. A new semiselective medium, acidified weak potatodextrose agar awpda with mertect active ingredient. Only induction by sun or ultraviolet light induced sporulation of alternaria porri f. It can infect all aboveground parts of the plant in addition to the bulb.
There is an immediate need for identification of effective resistance sources for use in host resistance breeding. Alternaria leaf blight is a foliar disease of carrots caused by the fungus alternaria dauci. In south texas, usa, purple blotch causes major foliage losses in onion miller, 1983. All the fungicides tested show control of purple botch alternaria porri in the onion crop. Oct 16, 2014 the omnipresent fungal genus alternaria was recently divided into 24 sections based on molecular and morphological data. Purple blotch caused by alternaria porri, on onion. Morphology of infection of onion leaves by alternaria porri. Cultural control optimal timing of sowing or transplanting can minimize purple blotch attack by a.