Formosana
At Du Roi Laboratory, we are future focused. We are invested in developing new disease resistant plants, primary among which is the commercialization of Formosana — a highly tolerant variety to FOC TR4 – Panama Disease.
Introduction
- Formosana is a cavendish banana variety with a high tolerance to Fusarium Oxysporum f. sp. cubense Tropical Race 4 (Foc TR4), which was acquired through somaclonal variation by the Taiwan Banana Research Institute.
- It is derived from tissue culture plants of Giant Cavendish, which was the primary variety used in Taiwan before the presence of Fusarium wilt.
- From a list of Giant Cavendish somaclonal selections, the first tolerant plant to be selected, tested, and released successfully to commercial growers was named Tai Chiao No.1 (also known as GCTCV-215-1).
- Further testing led to the identification of another improved Giant Cavendish selection which has been named Formosana (also known as GCTCV-218). Formosana replaced Tai Chiao No. 1 in infested orchards in Taiwan due to its improved tolerance and horticultural characteristics.
Tolerance to Fusarium Wilt
Tolerant Cavendish varieties has been a long-sought strategy to manage Foc TR4. Studies (Hwang & Ko, 2004; Molina et al., 2016; Viljoen et al., 2020) showed that Formosana is significantly more tolerant to Foc TR4 than susceptible Cavendish varieties such as Williams and Grand Nain.
In Taiwan, Formosana had a disease incidence of 4.3% in the parent crop and 4.1% on the ratoon crop. The corresponding figures were 25.5% and 29.6% for the wilt susceptible Giant Cavendish. In the Philippines, Formosana had an average disease incidence of 6% vs 74% of Grand Nain between 2008 and 2011. In another trial conducted between 2012 and 2015, the disease incidence of Formosana was 8%, comparing to the 87% of susceptible Grand Nain in the same TR4 infested plot.
In Mozambique, a disease rating out of 5 were given to plants planted in TR4 infected soil. Formosana had an average disease rating of less than 2 in the plant crop, and less than 2.5 in the ratoon crop, while Nandi had an average disease rating of more than 4.5 in the plant and ratoon crop (Viljoen et al., 2020)
General cultivation guidelines for Formosana
1) Formosana is a highly tolerant variety to Foc TR4. It will show less severe symptoms than susceptible varieties when grown under similar environmental conditions and inoculum pressure. It is important that the use of Formosana should form part of an integrated approach to the management of Foc TR4.
2) Bunches need good propping in the field due to plants being tall.
3) Formosana need optimal climate, soil, and management conditions to perform at its best. It is not recommended for marginal areas with poor drainage and insufficient irrigation.
