Subtropically grown bananas have differential interactions with Fusarium oxysporum f. sp. cubense (Foc), causal agent of Fusarium wilt of banana (FWB), when compared with those grown in the tropics. The designation 'subtropical' race 4 (SR4) was assigned to Foc strains able to infect Cavendish (AAA) cultivars in the subtropics, but not in the tropics. 'Tropical' race 4 (TR4) gained prominence with the appearance and spread of a Foc strain that severely affects Cavendish bananas in both the tropics and subtropics. Recent surveys in Asia revealed TR4 as the predominant strain both in the tropics and subtropics, affecting not only Cavendish, but also many other cultivars. In many subtropical banana zones, Foc races 1 and 2, which complete the racial structure of Foc, are also found and cause severe losses in certain market-preferred dessert bananas. Environmental constraints increase the susceptibility of Cavendish bananas to SR4. However, the role of abiotic stresses in cultivar susceptibility to FWB needs to be better understood. It is not clear why some Foc strains only affect Cavendish in the subtropics, and what other factors, including pathogen virulence and microbial functional diversity, might be driving disease epidemics. Field experience suggests that optimum soil and water management strategies can reduce disease intensity, but targeted studies are needed to understand the virulence of different strains, the impact of fluctuating temperatures, soil pH, organic matter breakdown and soil microbial dynamics. Research findings on the epidemiology and management of FWB in Australia, Brazil, China, India and South Africa are discussed to propose priority areas for the development of improved disease management practices.

Abstract. Grapevine leaf rust, caused by Phakopsora euvitis Y. Ono, was detected on grapevine leaves (Vitis sp.) in Darwin, in the Northern Territory. This is the first record of this pathogen in Australia.A P 0 2 0 6 0 M . P . W e i n e r t e t a l .

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Isolates of Pseudoperonospora cubensis from the Murrumbidgee Irrigation Area (MIA), New South Wales, and the Burdekin district, Queensland, were compared for metalaxyl sensitivity with a known sensitive isolate. Several different fungicide application techniques were used (foliar sprays, soil drenches, floating leaf discs), but the relativity of metalaxyl sensitivity between isolates was maintained. Isolates from the Burdekin district were highly resistant and came from fields where control of downy mildew was poor. Isolates from the MIA showed intermediate sensitivity but there was no apparent loss of field control. In a floating disc experiment the EC50 values of sensitive, intermediate, and resistant isolates were in the ranges >0.01-<0.1, >1-<10, and >100 �g metalaxyl/mL, respectively.

Australia-Pakistan Agriculture Sector Linkage Program collaboration (2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013) is developing integrated crop management practices to enhance value chain outcomes for the mango industry in Pakistan and Australia. One component involves scaling up orchard management strategies which optimise nutrition, enhance constitutive resistance of mango fruit and reduce field disease inoculum as key underpinning the reduction of postharvest disease losses. The strategies include optimal tree nutrition, tree pruning and inoculum reduction and strategic use of field sprays with fungicides. This is coupled with a longer-term improvement of nursery stock, screening for cultivar resistance and selection of clean planting material as means of reducing stem end rot, anthracnose and (inAustralia) dendritic spot. The research outcomes of crop management research from 2005 to 2010 are being demonstrated at different grower orchards in 25 integrated research block sites in both the Punjab and Sindh mango growing areas of Pakistan. The blocks have been established in the form of village or district clusters for easy management and to serve as demonstration blocks to adjacent or neighbouring farms. Pre harvest management protocols will be validated in the research blocks to finetune and assess their agronomic and disease reduction potential, and to foster grower ready adoption. The disease reduction risk and shelf-life potential of fruit from the blocks will be further tested in domestic and export market situations.