By Jeff Daniells, DAF

With the outbreak of Fusarium wilt TR4 in Tully there has been increasing interest in tolerant/resistant varieties. Recent studies in the Philippines have indicated that the Saba type cooking banana, Cardaba has tolerance to TR4.

In the Philippines and Indonesia more Saba type bananas are grown than any other type of banana, including both cooking and dessert types. Saba production figures for the Philippines were 2.6 million tonnes in 2011. They are particularly popular as snacks – mostly boiled, fried or barbecued.

DAF imported the Saba type banana Pisang Gajih Merah from Indonesia several years ago and this is what was found…

Subheading: Market opportunities

Given the popularity of this type of banana in the Philippines, Indonesia and to a lesser extent Malaysia, one would expect a small but ready market opportunity amongst these ethnic communities in Australia.

The number of migrants from these three countries living in Australia was 171,000, 63,000 and 116,000 respectively in 2011. However, the target market need not just be restricted to this demographic. All those that I have had the opportunity to introduce to the taste of these bananas, think that they’re great.

An easy and nutritious way to enjoy them is to boil them in the ‘jacket’ (peel on) until cooked through, peel and serve as a side vegetable at meal time.  They are a great ‘light’ alternative to potato.

It is best to select fruit that is not fully ripe for this purpose because this gives the right combination of starchiness and sweetness.

Additionally, this is the preferred variety for the consumption of bells and for leaves for wrapping purposes in cooking for the three countries mentioned.

Subheading: Internal fruit disorder

Unfortunately, since the introduction of this variety we have encountered a physiological disorder greatly affecting internal fruit quality characterized by hard and discoloured regions in the fruit pulp.

The disorder is seasonal in nature but to date no pathogens have been isolated from samples of affected fruit. In north Queensland the disorder is confined to bunches harvested during the period June to November. This translates to bunches which have emerged roughly in the period February to July.

The disorder may be nutritional – perhaps a deficiency of calcium and/or boron brought about by the lack of nutrients reaching the fruit under wet season and/or cooler conditions. Studies are required to investigate this further.

The question is, how else might this problem be approached? Perhaps the disorder may be less of a problem outside of wet tropical coast of north Queensland. Alternatively, one could consider producing/marketing this cooking banana from north Queensland as a seasonal fruit – i.e. managing the time of bunching (time of planting/judicious follower selection/nurse suckering) to coincide with the required harvesting period from December to May and so avoid the disorder.

Subheading:  Yield/plant characteristics

Pisang Gajih Merah is a large vigorous plant with a robust pseudostem and is relatively resistant to important leaf diseases.  The fruit are short and distinctively squarish and angular. The trial data presented in Table 1 shows that Pisang Gajih Merah had slightly heavier bunches than Lady
Finger but still only about 59 per cent of the yield of Williams Cavendish.

Table 1. Yield and plant characteristics of Pisang Gajih Merah (results are from South Johnstone and are averaged over a plant crop and two ratoons – all bunches were harvested when they began to ripen in the field).

Variety	Bunch Wt (kg)	Crop Cycle (months)	Pseudostem Ht. (m)	Finger Length (cm)
Pisang Gajih Merah	25.1	10.8	4.9	20.0
Lady Finger	21.2	11.0	4.1	20.6
Williams	42.8	10.9	2.9	28.2

Sub-heading: Fusarium Wilt tolerance?

Pisang Gajih Merah is being screened against TR4 in the Northern Territory this past year to see just what level of tolerance it might have in Australia.

So far it is looking very promising at the end of the plant crop.  Previously it has been screened against Race 1 and Subtropical race 4 in the cool subtropics of Australia but was considered relatively susceptible to those races under those conditions.

We have also screened it against Race 1 in north Queensland.

Towards the end of the first ratoon crop Pisang Gajih Merah has not had any Fusarium wilt symptoms evident whilst the very susceptible check variety Dwarf Ducasse has exhibited wilt symptoms since early in the plant crop.

Subheading: Planting material?

The recommended type of planting material is pest and disease free tissue cultured plants. This cannot be emphasised enough given the risk of TR4 spread with conventional planting material in north Queensland.

Interested growers should contact Sharon Hamill, Senior Principal Scientist at Queensland DAF’s Maroochy Research Station (07 53811342).