Fieldapplied fungicides and postharvest treatments to control asparagus diseases posing biosecurity threats to New Zealand
| Autor: | L-H. Cheah, C.M. Horlock |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | New Zealand Plant Protection. 60:94-98 |
| ISSN: | 1179-352X 1175-9003 |
| Popis: | Collaborative research between New Zealand and Australia has investigated field-applied fungicides and postharvest treatments for control of asparagus rust (caused by Puccinia asparagi) and phomopsis stem blight of asparagus (caused by Phomopsis asparagi) in Queensland. In a 2004 field trial, the fungicides difenoconazole and propiconazole reduced the incidence of asparagus rust. In a 2005 field trial, four fungicides (carbendazim, chlorothalonil, iprodione and propiconazole) reduced the severity of phomopsis stem blight. Postharvest disinfection with sodium hypochlorite or with calcium hypochlorite at 50 ppm was highly effective at reducing Pu. asparagi and Ph. asparagi spore germination on water agar. Integrated disease management based on field and postharvest methods are suggested to reduce the risk of importation of the diseases to New Zealand. Similar methods could be used for controlling these diseases if they establish. INTRODUCTION Three diseases, asparagus rust (caused by Puccinia asparagi), phomopsis stem blight (caused by Phomopsis asparagi) and asparagus anthracnose (caused by Colletotrichum gloeosporioides), were first detected on asparagus in Queensland, Australia, in 2000, but have not been recorded on asparagus in New Zealand. Both asparagus rust and phomopsis stem blight are causing significant crop losses in Queensland (Cheah et al. 2003; Beasley et al. 2004). These two diseases have already spread to production areas in Victoria, Australia, and since they could possibly spread to New Zealand, they are a threat to New Zealand’s biosecurity. With the emphasis of Biosecurity New Zealand on off-shore auditing, it is important to control or mitigate the risk of unwanted pests and diseases before they arrive at the border. From 2002 to 2004 collaborative research has been undertaken at the Queensland Department of Primary Industry and Fisheries and Crop & Food Research to investigate field and postharvest control of these diseases. This paper reports the results of trials of integrated control strategies based on field and postharvest methods for disease management that could be used before spears are imported into New Zealand. MATERIALS AND METHODS Phomopsis stem blight and asparagus rust field trial – 2004 season A field trial to determine the effectiveness of five different fungicides, benomyl, chlorothalonil, mancozeb, difenoconazole and propiconazole (Tables and 2), on phomopsis stem blight and asparagus rust was established near Warwick, Queensland, on summer regrowth of asparagus during January 2004. The field trial was carried out on established cv. Grande asparagus plants, which were approximately 0 years old. The fungicides were prepared as per manufacturers’ instructions (see Tables and 2 for rates) and applied to asparagus spears once ( days after emergence only) or twice ( days and 8 days after emergence). Fungicides were applied using a petrol-driven © 2007 New Zealand Plant Protection Society (Inc.) www.nzpps.org Refer to http://www.nzpps.org/terms_of_use.html |
| Databáze: | OpenAIRE |
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