A new semiselective medium, acidified weak potatodextrose agar awpda with mertect active ingredient. Natal submitted in fulfilment of the academic requirements. Alternaria porri altepooverview eppo global database. Because many of the members of this group have similar morphology, alternaria dauci has also been classified as formae specialis of carrots, or a. Alternaria dauci is included in the porri species group of alternaria, which is classified for having large conidium and a long, slender filiform beak. Purple blotch is caused by the fungus alternaria porri. It can infect all aboveground parts of the plant in addition to the bulb. Older leaves and plants are more susceptible to infection.
Because many of the members of this group have similar morphology, alternaria dauci has also been classified as formae specialis of. Pdf morphology of infection of onion leaves by alternaria porri. Kingdom fungi 1fungk phylum ascomycota 1ascop subphylum pezizomycotina. Antracnosis colletotrichum truncatum 1 apply antracnosis colletotrichum truncatum filter.
Oswaldo arnulfo ramosvergara1, luis eduardo gonzalezcepeda1, marcelino federico isaurojeronimo1 y dagoberto guillensanchez2. It is responsible for causing severe yield losses ranging from 2. Mancha purpura alternaria porri na cultura da cebola. 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. Cultural control optimal timing of sowing or transplanting can minimize purple blotch attack by a. Purple blotch, alternaria porri, causing spots on leaves of shallots. The yield loss could vary from 25 to 50% quadri et al. Only induction by sun or ultraviolet light induced sporulation of alternaria porri f. Trichoderma asperellum, a potential biological control agent.
Efectividad biologica del fungicida mirage procloraz. 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. Purple blotch, alternaria porri, on leaves of shallots showing zoned spots. Purple blotch of onion angela madeiras, umass extension diagnostic lab purple blotch is caused by the fungus alternaria porri. The omnipresent fungal genus alternaria was recently divided into 24 sections based on molecular and morphological data. Identification of novel source of resistance and differential. Garlic and leeks may be affected as well as onions. Largespored alternaria pathogens in section porri disentangled.
It is an important disease in warm, humid oniongrowing regions around the world. Documents about alternaria porri altepo this website uses cookies our website uses cookies to ensure that we give you the best possible online experience. Purple blotch caused by alternaria porri, on onion. Common onion diseases to watch out for farmers weekly. Although it can be seedborne, it usually starts off from crop residue. A rotation of several years will be required after an. We do not use these to store personal information about you. Based on these positive results, in this study, we evaluated the potential of t. Effect of light on sporulation of alternaria porri f. The best ways to manage the disease is to grow disease resistant varieties.
The highest spore production ofstemphylium botryosum f. Alternaria porri moho negro aspergillus niger podredumbre del cuello botrytis aclada. Development of selective media for the isolation and. Increased ploughing between seasons reduced the disease, probably by reducing the amount of soilborne inoculum gupta and pathak, 1987. Phytophthora porri foister, transactions of the botanical society of edinburgh 30.
Article history evaluation of onion genotypes against purple. Late varieties on the highveld and in northern areas are vulnerable as they will still be growing when the rainy season starts. Biological effectiveness of mirage procloraz for the control of purple blotch alternaria porri on onion. Article history evaluation of onion genotypes against. A total of 43 allium genotypes were screened for purple blotch resistance under field conditions.
Oct 16, 2014 the omnipresent fungal genus alternaria was recently divided into 24 sections based on molecular and morphological data. Spores are produced in large numbers on these spots. 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. 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. Evaluation of several fungicidas in the control of alternaria porri ellis cif. Productos con alternaria en cebolla, pagina 1 informacion y precios. Malezas enfermedades plagas mancha purpura alternaria porri. Continuing to use this website means you agree to our use of cookies.
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. Morphology of infection of onion leaves by alternaria porri. Rabi season problem of purple blotch alternaria porri and stemphylium blight stemphylium vesicarium, which again pulls down the productivity. Download fulltext pdf download fulltext pdf morphology of infection of onion leaves by alternaria porri article pdf available in canadian journal of botany 728. Image subid scientific name common name autid photographer org baseimgurl landscape description. Hence, the present study was undertaken to evaluate the. Trichoderma asperellum, a potential biological control. All the fungicides tested show control of purple botch alternaria porri in the onion crop. The large spots are oval, purple and up to 150 mm long.