The introduction of novel vegetables requires extensive research.
A HOST OF UNFAMILIAR VEGETABLES—Japanese artichokes, pepinos, Cape gooseberries, Peruvian parsnips, tuberous chervil, sea kale, skirret—are now available to enliven the diet of those who are tired of carrots, leeks, and potatoes. Jean-Yves Péron and his colleagues at the École Nationale d’Ingénieurs des Travaux de l’Horticulture et du Paysage in Angers are studying forgotten or unknown vegetables with a view to improving their reproduction and cultivation. Not only are food lovers eager to try these novel varieties, but economists also welcome the interest of the Angevin agronomists in promoting diversification because saturation of the market for garden produce diminishes the profitability of capital investment. And from the point of view of farmers, cultivating a new or neglected vegetable sometimes is necessary if they are to increase demand for their products.
In Search of Ancient Agronomists
The introduction of new or forgotten vegetables entails a number of related studies: Producers need to be persuaded of the viability of new crops in both horticultural and commercial terms, and consumers have to be convinced of their gastronomic and nutritional interest. It took decades to bring the first Japanese artichokes and Peruvian parsnips to markets in France and a few restaurants. Tuberous chervil and sea kale will not be slow to follow.
Sometimes the reintroduction of a vegetable is made easier by older agronomic studies of the vegetable itself or, when no study has yet been carried out, members of the same family (the various cabbages in the case of sea kale; members of the parsley family, such as celery, in the case of tuberous chervil, and so on). Tuberous chervil, which grows wild in the east of France, was first identified by French agronomist Charles de l’Écluse in 1846. Nonetheless, despite the efforts of many gardeners of the period, its cultivation was never very widespread. When the researchers in Angers began their work, it was limited to a few truck farms in the Dole and Orléans regions.
Tuberous chervil traditionally is planted in the fall, and its roots, similar to carrots, are harvested the next July. Seed-bearing specimens are planted in December. Why is this vegetable largely unknown? No doubt there are a number of reasons: Germination does not take place without prior stratification; the germinating potency of seeds is limited to a year; crop yields are low; the root becomes edible and gastronomically pleasing only when it reaches a certain size, at which point it has a delicate taste similar to that of the chestnut; and the root is very sensitive to the saprophytic mushrooms that develop on surface lesions.
Seeking to remedy these two last defects, the Angevin researchers studied the genetic variability of the species by crossing wild plants with greenhouse specimens and by means of in vitro cultivation, using plant tissues and growth hormones to develop variants. At the same time they looked for ways to improve cultivation methods. In particular, they wondered how the dormancy period of tuberous chervil seeds could be eliminated and the plant population optimized. Because the mechanisms responsible for inhibiting fertilization in related plants (sometimes associated with the presence in the walls of a ripened ovary of inhibitory substances that are easily removed) were already understood, the agronomists were able to test various methods for eliminating the dormancy period under controlled conditions: variations in temperature, light cycles, application of growth regulators (gibberellin and cytokinin), conservation under oxygen-free conditions, and so on. Finally, they showed that dormancy is embryonic in nature; that its onset occurs during the last stages of the seeds’ maturation, once they have lost most of their water; and that it can be blocked only if the seeds have been exposed to a cool, moist environment for eight to ten weeks.
This research has also led to the creation of new plant lines and the selection of a number of commercially promising hybrids. By themselves, however, such studies do not guarantee that the new vegetable will be brought to market. Growing techniques must be explained to farmers and seed manufacturers, and promotional efforts aimed at bringing it to the attention of the public must continue until it reaches buyers’ dinner tables. Nutritional studies therefore are needed to determine how a new vegetable is best prepared. For example, tuberous chervil loses starch, gains in various reductive sugars, and develops its distinctive flavors during storage. Recipes created by renowned chefs on the basis of these studies can make a great difference in determining whether the new (or newly reintroduced) vegetable is accepted.