1. What Counts as an "Off-Spec" Vegetable, and How Much Is There?
Japan's food system grew up around wholesale markets, and the study says that moving large amounts of produce over long distances this way works best when it is sorted by size and shape. Those sorting rules are called specifications, or "specs." A vegetable that does not meet them is called off-spec (some countries say "B-grade" or "cosmetically imperfect"). It can taste exactly the same. It just looks different [1].
The authors of the study I use here estimate the amount indirectly. They subtract the amount of vegetables shipped from the amount harvested, using national statistics from Japan's agriculture ministry. For 2022, that gap was about 1.627 million metric tons, roughly 13% of the harvest. In 2000 it had been about 19%, so the share has been shrinking, partly because growing methods and shipping rules changed [1]. This gap counts everything that was harvested but not shipped, so it is only a rough stand-in for odd-looking vegetables.
That is a lot of food. So what happens when a farmer sells some of it cheaply, close to home?
2. Which Misshapen Vegetables Sold Well at Farmers' Markets, and Which Did Not?
In Japan, a chokubaijo is a farmers' market or farm shop where growers bring their own produce and often choose their own prices. A research team from Japanese universities studied these shops, looking at tomatoes, cucumbers, carrots, and radishes (daikon) [1].
They asked two questions. First, do farmers put in effort to turn off-spec vegetables into something sellable, instead of throwing them away? Second, when an off-spec vegetable sits next to a standard one, do shoppers actually pick it? Tomatoes, cucumbers and carrots passed both tests. Radishes failed the second: shoppers did not choose them often enough, and the authors conclude that off-spec radishes are not yet distributed well through these shops [1].
The study text I could read does not explain why shoppers chose radishes less often, so I will not guess. What it does show is that "off-spec" is not one thing. The same cheap price can help with one vegetable and not with another. And this is a result from particular shops, so it cannot be applied to every vegetable in every store.
3. Is a Low Price the Same as Losing Money?
Not necessarily. A low price hurts a farmer when it falls below what it cost to grow and deliver the vegetable. If a farmer who would otherwise throw a crooked cucumber away can sell it for something, that is money that would not exist otherwise. This is my own reasoning from the study's design, not a number the authors report.
The study's second test matters here, because it asks whether shoppers choose off-spec vegetables on purpose, next to standard ones [1]. Shoppers who pick the cheaper crooked tomato because they like the deal are different from shoppers who only take what is left.
Fresh vegetables also make low prices more likely. Japan's agricultural price agency, ALIC, notes that vegetable harvests change with the weather and that most do not keep well. When the supply rises or falls, prices move with it [2]. In a year with a huge harvest, there may be more off-spec vegetables and lower prices at the same time. That is when a farmer is most likely to lose money. That is a likely effect of the pattern ALIC describes, not a measured figure for off-spec vegetables.
4. Why Do Farmers Grow More Than They Can Sell in the First Place?
Selling off-spec vegetables cheaply turns a leftover into a little income. It does not reduce how much is left over. And leftovers have a cause: Japan's agriculture ministry research office explains that growers deliberately plant a bit more than customers ordered, because running short is worse than having extra. Weather changes the harvest, and the real amount is only clear just before shipping, so extra vegetables sometimes get thrown away [3].
To tackle that, researchers built an app for hydroponic spinach (grown in nutrient water rather than soil) that uses local weather data to forecast the harvest one week ahead. The ministry's summary says it can predict harvest amount with at least 84% accuracy, and length with at least 91%, though the page I read does not explain how that was measured. The idea is that growers can line up buyers for extra spinach earlier, which is expected to cut waste [3]. The page I read describes this as an expectation, and it covers spinach only, so I cannot say how much it would help for radishes or cucumbers.
5. So When Does Selling Odd-Looking Vegetables Cheaply Hurt a Farmer?
Putting it together, a cheap price on odd-looking vegetables seems to be fine for a farmer when three things hold: shoppers really choose the vegetable, the price still covers the cost of growing and selling it, and the farmer did not grow a huge amount that nobody could buy. It tends to cause trouble when a vegetable such as the radish in this study does not attract shoppers, or when a big harvest pushes prices down at the same time.
These are the connections I draw from the sources. None of the sources tests all three conditions together.
6. How Can You Check This at a Store or Farm Shop Near You?
Look for a shelf of odd-shaped or "imperfect" vegetables at a supermarket, farm stand, or farmers' market. Note how much cheaper they are than regular ones. Visit at different times of day and see which items vanish first and which are still there. Just watch; don't touch the vegetables or get in the staff's way.
If you want the details behind the radish result, the study is open to read in the Journal of Food System Research. It is in Japanese, with an English abstract at the top [1].