Fusarium wilt (Panama disease), caused by the pathogen Fusarium oxysporum f.sp. cubense (FOC) Tropical Race 4 (TR4) is considered one of the largest threats to the national and global banana industries. TR4 is known to infect and often kill the economically and globally important Cavendish varieties. Currently, a varietal screening field trial is underway in the Northern Territory, examining 27 banana varieties, including Cavendish, FHIA and selected hybrid cultivars. This screening will determine the levels of tolerance or resistance to FOC TR4 of the tested banana varieties, with the aim of selecting superior tolerant varieties for further studies and improvement.
Trial plants were inoculated with FOC TR4 colonised millet at planting and were assessed for the first appearance of external disease symptoms which is commonly leaf yellowing and wilting and pseudostem splitting, while internal symptoms were assessed following plant death or crop harvest. Agronomic characteristics were also examined, such as bunch emergence, bunch weight and plant height. Assessments of trial plants show the Cavendish varieties Williams and DPM25 are the most susceptible to TR4. However, some FHIA, selected hybrid and other Cavendish varieties have thus far displayed strong tolerances to TR4 with no external symptoms observed with little to no internal symptoms at harvest.