White blister disease control in radish seed crops
DOI:
https://doi.org/10.30843/nzpp.2018.71.172Abstract
Albugo candida is a significant pathogen of many brassica species causing leaf spotting but, more importantly, hypertrophy of flowering stems (“stagheads”) resulting in yield loss. No chemicals are currently registered for white blister control in New Zealand. Little research has been carried out on white-blister management. The implications of seed transmission and subsequent disease expression in radish are not fully understood and control has relied on products containing metalaxyl-m+mancozeb. A range of fungicides were evaluated in two field trials and a pot trial for both efficacy against the disease and effect on radish yield. While metalaxyl-m+mancozeb improved yields in field trials and provided good disease suppression in pot trials, the fungicides azoxystrobin, boscalid+pyraclostrobin and cyazofamid were also equally effective or better than metalaxyl-m+mancozeb. Treatments were able to suppress leaf spotting by up to 90% and inflorescence infection by 50%. Seed yield increases of up to 67% were recorded. Potential new control options for white blister were identified providing alternatives to metalaxyl-m+mancozeb and thus contributing to an anti-resistance strategy.
References
CABI 2016. Crop Protection compendium datasheet for <em>Albugo candida</em> (white rust of crucifers). Wallingford, UK.
Cook RJ, Zhang BX 1985. Degrees of sensitivity to metalaxyl within the <em>Pythium</em> spp. pathogenic to wheat in the Pacific Northwest. Plant Disease 69: 686-688.
FAR 2016. White blister (white rust) disease in radish. Arable Updates - Vegetable Seeds 3. Foundation for Arable Research, Christchurch, New Zealand: 4 pp.
Fisher DJ, Hayes AL 1984. Studies of mechanisms of metalaxyl fungitoxicity and resistance to metalaxyl. Crop Protection 3: 177-184. <a href="https://doi.org/10.1016/0261-2194(84)90052-8">https://doi.org/10.1016/0261-2194(84)90052-8</a>
Kaur P, Sivasithamparam K, Barbetti MJ 2011. Host range and phylogenetic relationships of <em>Albugo candida</em> from cruciferous hosts in Western Australia, with special reference to <em>Brassica juncea</em>. Plant Disease 95: 712-718. <a href="https://doi.org/10.1094/PDIS-10-10-0765">https://doi.org/10.1094/PDIS-10-10-0765</a>
Matson MEH, Small IM, Fry ME, Judelson HS 2015. Metalaxyl resistance in <em>Phytophthora infestans</em>: assessing role of RPA190 gene and diversity within clonal lineages. Phytopathology 105: 1594-1600. <a href="https://doi.org/10.1094/PHYTO-05-15-0129-R">https://doi.org/10.1094/PHYTO-05-15-0129-R</a>
Molinero-Ruiz ML, Cordón-Torres MM, Martínez-Aguilar J, Melero-Vara M, Domínguez J 2010. Resistance to metalaxyl and to metalaxyl-M in populations of <em>Plasmopara halstedii</em> causing downy mildew in sunflower. Canadian Journal of Plant Pathology 30: 97-105. <a href="https://doi.org/10.1080/07060660809507500">https://doi.org/10.1080/07060660809507500</a>
Minchinton EJ, Galea V, Thomson F, Trapnell L, Murdoch C, Nadesan S, Kita N 2005. Disease management strategies for downy mildew on spring onions and white blister on radish. Horticulture Australia Ltd, Final Report: VG01045. Department of Primary Industries, Victoria, Australia. Pp. 35-37.
R Core Team 2014. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL <a href="http://www.R-project.org/">http://www.R-project.org/</a>.
Rimmer SR, Shattuck VI, Buchwaldt L (eds) 2007. Compendium of brassica diseases, APS Press, St Paul, MN, USA. Pp. 54-56.
