This is where the problem lies. Some farming is speculative and when a crop proved to be highly profitable one year, the following year others tend to join the bandwagon to see if they can cash in on its success. The additional production floods the market and causes a crash in farm gate prices.
This unfortunately is a fact of life in an unregulated market and has happened with may forms of agricultural production, some well known like aloe vera and ostriches to common crops which are less known.
Some markets have been regulated in the past such a dairy, but regulation often inflates prices and encourages lower efficiency production (those potentially on marginal land with high cost/impacts continue to farm due to high prices). The last industry I recall be regulated was potatoes in Western Australia.
Regulation would potentially suit some farmers as it would inflate farm gate prices at the expense of consumers and the export industry.
What is needed is for the industry associations to invest in research and development, such has been done with the likes of the wheat, sugar, cotton etc industry boards/association. Research and development leads not only to better yielding crops and lower per unit production costs, but also leads to post production product development. This is where it can be exciting as products can be developed to improve longevity of a product (e.g. turning bananas or sweet potatoes into flour or starches) and stabilise farm gate price fluctuations.
The only downside is that if the post production processing of the product becomes more lucrative than fresh, it can push up the fresh produce prices as fresh competes directly with the processed product demand. Such impacts are usually short term (a few years) until additional production occurs to meet the shortfall.