Plant Profile- Banana

It might sound strange but I am deeply suspicious of bananas, despite them being the most productive fruit producing plants on my farm up to this point. We now eat bananas just about every day, producing reasonable quality bunches throughout the year and freezing peeled ones to add to our smoothies almost every day. Ripening them properly produces a much nicer fruit compared to those in the shops picked green and ripened closer to their final destination with ethylene gas. Despite this generosity bananas encapsulate many things that are wrong with industrial agriculture, even when grown on a home garden scale. But let’s start at the beginning and work forward from there.

Banana is from the genus Musa, a large genus of diverse plants related to gingers and Canna. Wild banana species look similar to the domesticated ones, but with one key difference in their fruit which are filled with tiny rock hard seeds. The fruit are edible but much less appealing than cultivated forms. Naturally seedless mutants were first selected in Papua New Guinea around 10 000 years ago. A range of interspecies hybrids were domesticated mostly in south east Asia, with the hybridisation breaking their seed producing mechanisms, similar to how breeding a horse and donkey will create an infertile mule. Unlike animals these sterile hybrid bananas can be propagated by dividing suckers, allowing each useful hybrid to be propagated and spread by humans. The most productive hybrids that most people know today came from south east Asia, which spread out across the old world around 2000 to 3000 years ago. Most of the banana varieties around the world are grown as a staple crop called plantain, with the unripe starchy fruit being cooked like potato. The varieties that produce acceptable fruit when fully ripe are a small minority.

Growing bananas this way is not without its drawbacks. Over time banana clones accumulate various diseases, including bacteria, fungi and viruses. Normally in populations of plants undergoing sexual reproduction most viruses are eliminated during seed formation. The presence of higher levels of genetic diversity in each species population, along with mechanisms of sexual reproduction, kept a balance between the diseases and the plants. In sterile hybrids these mechanisms were lost, meaning that diseases gradually got worse over time. In areas where the wild species were still growing new hybrids could be created periodically in order to select new strains with sufficient resistance, and to maintain higher levels of diversity among sterile clones. In traditional societies bananas were also usually grown as isolated clumps scattered in the forest, meaning that a disease outbreak at one clump would not easily spread to its neighbours. When suckers are removed from even diseased bananas there is still a reasonable chance the disease will be left behind. After contact with the new world bananas were transported and became significant crops. They were an excellent follow up in heavily logged forest, extracting the nutrients unleashed by the disturbance, but exhausting the soil quite quickly. With the discovery of mined phosphorus and synthetic nitrogen during the industrial age banana quickly became the most dominant export fruit crop. Banana is unusual in being an especially heavy gross feeder, responding to high levels of nutrients with greater production. Plants that lack this ability can instead be overwhelmed by heavy fertiliser applications. This was coupled with cheap coal powered ships and the ability for the fruit to withstand long distance transportation to create the first intensive globalised form of fruit production, with horrific labour practices in the places which grew the crop. The sterile clonal banana was the ultimate mechanical plant, every one identical and predictable, where the input dials could be increased to maximum in order to crank up production.

Such a boom could never last of course. The fungi which had been quietly pushing back and forth with bananas since before domestication quickly cracked the immune system of the dominant commercial cultivar, the Gros Michel, and rapidly spread through the crowded banana monocultures. If you have ever eaten fake banana flavour you may have noticed how it is richer than fresh bananas. This is because the fake flavour composition was designed based on the superior Gros Michel. The fungus led to a collapse of the banana export industry, with the inferior Cavendish taking its place a while later due to its (temporary) resistance. New fungal strains have now emerged which are poised to destroy this cultivar as well. Currently advanced techniques of genetic engineering are being tested to see if the fungal tide can be held back, at least until another fungal strain overcomes that defence.

Because of this origin story I see banana as a fruit with no long term future in my zero input system. Without the ability to breed the crop it is a dead end that will eventually fall to disease. Currently it is permitted to grow backyard bananas from tissue culture that are free of diseases without a permit in my state (Queensland). This is where I originally got my main varieties. Dwarf ducasse is a very short plant which allows bunches to be managed without a ladder. The fruit are fairly small, thin skinned, with a fairly bland and firm flesh even when fully ripe. The other main variety is bluggoe, a medium height variety that produces large bunches of very tasty fruit. I also trialed pisang ceylon but found it was too tall and narrow and prone to falling over, but might work better in a more protected situation. The novelty types blue java and red ducca were underwhelming, both in productivity and quality and are being phased out. Lady finger are also common in the area but too tall to be easily managed. I prefer to leave bunches unprotected and monitor them closely. Most of the time I can tell when the bunch is close to ripe due to the skin changing to a different more silvery shade of green, and the final leaves on the stalk being reabsorbed (though different varieties vary in how they do this). I can then usually time bringing in the bunch so I only lose a couple of bananas to birds that ripen first at the top. For taller varieties I cut half way through the stem at chest height, allowing me to pull the top of the plant and bunch over slowly to allow for safe harvesting. No bunch of bananas is worth falling of a ladder. I also found bunches covered in protective bags normally got left until all the fruit was over ripe since they cannot be easily inspected at a distance.

I have also tried different ways of growing the bananas. Originally they were planted on a fairly flat area upstream from a dam, a site I thought would have ample water. The location turned out to collect cold air in winter and be relatively dark at that time due to nearby trees. The soil was also fairly shallow and likely acidic, better for blueberries. The plants grew but struggled. A nearby clump on a higher soil shelf were more productive, likely since cool air couldn’t pool there in winter. I moved some suckers up hill to the gentle downhill slope from my vegetable garden, thinking that the bananas would readily soak up any nutrients leaching downhill. I also dug shallow trenches uphill from them to help collect and slow down run off water. I made sure to interrupt these trenches along the long banana row. That way I didn’t need to worry too much about orientation relative to contour since water was unable to run from one end of the trench to the other uninterrupted. These plants closer to the house also get a regular splash of undiluted urine, pandering to their gross feeding tendencies. The result has been spectacularly healthy plants and ample production.

Bananas also suffer from relatively synchronised production in my non-irrigated system, with plants slowing growth during dry spells then tending to fruit all together when rain returns. This means I can often harvest several large bunches within days of each other. With current technology they can be easily peeled and frozen in zip lock bags, but this approach may not be possible one day as industrial society unwinds. They can also be dehydrated, but this approach requires a lot of electricity or at a minimum heat energy. Solar dehydrators are possible, but do not perform well during the extended wet weather that usually coincides with bumper harvests. Growing plantains could be an option but they would still suffer the sterile clone issues, and are not particularly productive outside of the wet tropics.

Ideally bananas could be grown much as they are in south east Asia, with established populations of diverse wild species providing a genetic resource for the creation of new and diverse sterile clones as required. Instead the industrial approach is to try to control and eliminate multiple serious microbial diseases that routinely break through the most thorough countermeasures and are almost impossible to eradicate once established. This is to protect an intensive industrialised industry with no long term future in a deindustrialised world, at the expense of preventing a more small scale, diverse and sustainable system forming instead. But I have the sense to know to pick my fights carefully and even in a best case scenario the banana is a strange dead end crop. It is a perfect example of how a breeding program can find itself trapped in an optimum where maximum productivity is the only criteria at play. It is kind of like choosing for all your children to be Olympic level athletes, but at the expense of them all being infertile. That cold, dead gold will be their only enduring legacy. I would prefer to invest my energy in plants that have a life of their own so we can forge our destinies together.

Remnants of my original planting, already showing cold stress

The smaller planting of dwarf ducasse on a higher shelf, with good bunches forming

Medium height bluggoe with a bunch starting to change colour in front, and one just forming behind. Winged yams make a good companion.

A dwarf ducasse bunch colouring up, with only a couple of fruit lost to birds despite being unprotected. If I waited another few days though I would lose them all.